diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 8ef9f42d..1c8a1e9c 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -31,6 +31,36 @@ jobs:
 
       - run: composer test
 
+  php8-4:
+    name: Unit Tests php8.4 (php ${{ matrix.php-version }})
+    runs-on: ubuntu-latest
+    # always run on push events
+    # only run on pull_request_target event when pull request pulls from fork repository
+    if: >
+      github.event_name == 'push' ||
+      github.event_name == 'pull_request_target' && github.event.pull_request.head.repo.full_name != github.repository
+    strategy:
+      fail-fast: false
+      matrix:
+        php-version: [ 8.4 ]
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: shivammathur/setup-php@2.9.0
+        with:
+          php-version: ${{ matrix.php-version }}
+
+      # Remove php-cs-fixer until compatible with PHP 8
+      # This step might be removable if php-cs-fixer is compatible with 8.4 by the time this runs
+      - run: composer remove --dev --no-update --no-interaction friendsofphp/php-cs-fixer
+
+      - run: composer self-update
+
+      - run: composer install --no-interaction --prefer-source --dev
+
+      - run: composer test
+
   php7-4:
     name: Unit Tests php7.4 (php ${{ matrix.php-version }})
     runs-on: ubuntu-latest
@@ -109,4 +139,3 @@ jobs:
       - run: composer install --no-interaction --prefer-source --dev
 
       - run: composer test
-
diff --git a/.php-cs-fixer.cache b/.php-cs-fixer.cache
new file mode 100644
index 00000000..c0dde319
--- /dev/null
+++ b/.php-cs-fixer.cache
@@ -0,0 +1 @@
+{"php":"8.1.27","version":"3.22.0:v3.22.0#92b019f6c8d79aa26349d0db7671d37440dc0ff3","indent":"    ","lineEnding":"\n","rules":{"array_syntax":{"syntax":"short"},"no_unused_imports":true,"ordered_imports":{"imports_order":["const","class","function"]},"php_unit_fqcn_annotation":true,"phpdoc_return_self_reference":true,"phpdoc_scalar":true},"hashes":{"\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder2419\/examples\/digitalidentity\/app\/Http\/Controllers\/IdentityController.php":"369515522c3efd6cd55a8363d4e97c05","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder4308\/src\/Identity\/Policy\/Policy.php":"e1bca74eaafe5271dd1a38769fe1c3b2","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder3692\/src\/Identity\/Policy\/PolicyBuilder.php":"88302b88aba33563661d4b989b5dc429","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder2054\/tests\/Identity\/Policy\/PolicyBuilderTest.php":"a262a261102744a1acf6d5d0b421dc44","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder5221\/src\/Identity\/ReceiptBuilder.php":"2e6ef33d3401f7cbd36145ad66b3b2ef","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder289\/examples\/digitalidentity\/app\/Http\/Controllers\/ReceiptController.php":"e79ec7e1511895c954f77c713d435ad2","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder2348\/tests\/Identity\/ReceiptTest.php":"b602e6828020fef411df597e17fa7c88","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder4139\/examples\/digitalidentity\/routes\/web.php":"dcdc77843f3e59dd61467a324edf0c77","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder5396\/src\/Identity\/Receipt.php":"4744c8887009fd9ffbf084f99021eb1c","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder5193\/src\/Identity\/WrappedReceipt.php":"3a77a22be093a1da75438ea2bb9fcb20","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder4416\/examples\/digitalidentity\/app\/Http\/Controllers\/AdvancedIdentityController.php":"6b5c23f2ce8da246bc41d136d87ecdb6","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder5544\/examples\/digitalidentity\/app\/Http\/Controllers\/AdvancedIdentityController.php":"6b5c23f2ce8da246bc41d136d87ecdb6","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder4533\/src\/Identity\/Policy\/Policy.php":"bea4b7ebb268fca1ad719f933ec82cbd","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder3559\/tests\/Identity\/Policy\/PolicyBuilderTest.php":"f6d7380ae2db4eca426bb39ccfb3a900","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder2922\/examples\/digitalidentity\/routes\/web.php":"fdf260e4dfd18c8ba12078943564875a","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder3947\/src\/Constants.php":"4bb1127c9665c5d0496b90ea3211951d","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder4440\/src\/Constants.php":"99a3224f6e3fcae067362798bbab64f0","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder4745\/src\/Constants.php":"afc40e02bdc3a87ff7a874826447c604","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder1311\/src\/Constants.php":"77a8a39eac3e973495b7719ebd41509e","\/private\/var\/folders\/b6\/tqq9d7y54ll62fjfysz50ry80000gn\/T\/PHP CS Fixertemp_folder1635\/examples\/digitalidentity\/app\/Http\/Controllers\/ReceiptController.php":"10f70ffe111a0030b29762494cc5de7d"}}
\ No newline at end of file
diff --git a/README.md b/README.md
index 6f35b579..e6dadebc 100755
--- a/README.md
+++ b/README.md
@@ -42,13 +42,13 @@ Add the Yoti SDK dependency:
 
 ```json
 "require": {
-    "yoti/yoti-php-sdk" : "^4.3.0"
+    "yoti/yoti-php-sdk" : "^4.4.0"
 }
 ```
 
 Or run this Composer command
 ```console
-$ composer require yoti/yoti-php-sdk "^4.3.0"
+$ composer require yoti/yoti-php-sdk "^4.4.0"
 ```
 
 ## Setup
diff --git a/composer.json b/composer.json
index 95ef8a52..b08dca14 100755
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
   "name": "yoti/yoti-php-sdk",
   "description": "Yoti SDK for quickly integrating your PHP backend with Yoti",
-  "version": "4.3.0",
+  "version": "4.4.0",
   "keywords": [
     "yoti",
     "sdk"
@@ -9,7 +9,7 @@
   "homepage": "https://yoti.com",
   "license": "MIT",
   "require": {
-    "php": "^7.4 || ^8.0 || ^8.1",
+    "php": "^7.4 || ^8.0 || ^8.1 || ^8.4",
     "ext-json": "*",
     "google/protobuf": "^3.10",
     "phpseclib/phpseclib": "^3.0",
diff --git a/examples/digitalidentity/README.md b/examples/digitalidentity/README.md
index 3673b72a..9bf2d1b3 100644
--- a/examples/digitalidentity/README.md
+++ b/examples/digitalidentity/README.md
@@ -24,4 +24,4 @@ This example requires [Docker](https://docs.docker.com/)
 ## Digital Identity(Advanced) Share Example
 * Visit [/generate-advanced-identity-share](https://localhost:4002/generate-advanced-identity-share)
 * ## Digital Identity DBS Example
-* Visit [/generate-dbs-share](https://localhost:4002/generate-dbs-share)
\ No newline at end of file
+* Visit [/generate-dbs-share](https://localhost:4002/generate-dbs-share)
diff --git a/examples/digitalidentity/resources/views/dbs.blade.php b/examples/digitalidentity/resources/views/dbs.blade.php
index 1359cc7c..9f325177 100644
--- a/examples/digitalidentity/resources/views/dbs.blade.php
+++ b/examples/digitalidentity/resources/views/dbs.blade.php
@@ -85,5 +85,6 @@ function onErrorListener(...data) {
         await onReadyToStart()
     }</script>
 <script src="https://www.yoti.com/share/client/v2" onload="onClientLoaded()"></script>
+
 </body>
 </html>
diff --git a/examples/digitalidentity/routes/web.php b/examples/digitalidentity/routes/web.php
index 3fb377e7..f0e02806 100644
--- a/examples/digitalidentity/routes/web.php
+++ b/examples/digitalidentity/routes/web.php
@@ -19,4 +19,4 @@
 Route::get('/generate-advanced-identity-share', 'AdvancedIdentityController@show');
 Route::get('/generate-advanced-identity-session', 'AdvancedIdentityController@generateSession');
 Route::get('/generate-dbs-share', 'DbsController@show');
-Route::get('/generate-dbs-session', 'DbsController@generateSession');
\ No newline at end of file
+Route::get('/generate-dbs-session', 'DbsController@generateSession');
diff --git a/examples/doc-scan/app/Http/Controllers/HomeController.php b/examples/doc-scan/app/Http/Controllers/HomeController.php
index 299fa6b1..f116e776 100644
--- a/examples/doc-scan/app/Http/Controllers/HomeController.php
+++ b/examples/doc-scan/app/Http/Controllers/HomeController.php
@@ -103,11 +103,12 @@ public function show(Request $request, DocScanClient $client)
                     ->withMaxRetries(3)
                     ->build()
             )
+            /*
             ->withRequestedCheck(
                 (new RequestedWatchlistAdvancedCaCheckBuilder())
                     ->withConfig($customConfig)
                     ->build()
-            )
+            )*/
             ->withRequestedCheck(
                 (new RequestedFaceMatchCheckBuilder())
                     ->withManualCheckFallback()
@@ -150,6 +151,7 @@ public function show(Request $request, DocScanClient $client)
                     ->withErrorUrl(config('app.url') . '/error')
                     ->withPrivacyPolicyUrl(config('app.url') . '/privacy-policy')
                     ->withBiometricConsentFlow('EARLY')
+                    ->withBrandId('brand_id')
                     ->build()
             )
             ->withRequiredDocument(
diff --git a/src/Aml/Profile.php b/src/Aml/Profile.php
index b0ee2a10..d03219c3 100644
--- a/src/Aml/Profile.php
+++ b/src/Aml/Profile.php
@@ -50,7 +50,7 @@ class Profile implements \JsonSerializable
      * @param \Yoti\Aml\Address $amlAddress
      * @param null|string $ssn
      */
-    public function __construct($givenNames, $familyName, Address $amlAddress, string $ssn = null)
+    public function __construct(string $givenNames, string $familyName, Address $amlAddress, ?string $ssn = null)
     {
         $this->givenNames = $givenNames;
         $this->familyName = $familyName;
diff --git a/src/Constants.php b/src/Constants.php
index b1cb4499..67486d3d 100644
--- a/src/Constants.php
+++ b/src/Constants.php
@@ -31,7 +31,7 @@ class Constants
     public const SDK_IDENTIFIER = 'PHP';
 
     /** Default SDK version */
-    public const SDK_VERSION = '4.3.0';
+    public const SDK_VERSION = '4.4.0';
 
     /** Base url for connect page (user will be redirected to this page eg. baseurl/app-id) */
     public const CONNECT_BASE_URL = 'https://www.yoti.com/connect';
diff --git a/src/DocScan/Session/Create/Check/RequestedLivenessConfig.php b/src/DocScan/Session/Create/Check/RequestedLivenessConfig.php
index 050655db..07db4fea 100644
--- a/src/DocScan/Session/Create/Check/RequestedLivenessConfig.php
+++ b/src/DocScan/Session/Create/Check/RequestedLivenessConfig.php
@@ -23,7 +23,7 @@ class RequestedLivenessConfig implements RequestedCheckConfigInterface
      */
     private $manualCheck;
 
-    public function __construct(string $livenessType, int $maxRetries, string $manualCheck = null)
+    public function __construct(string $livenessType, int $maxRetries, ?string $manualCheck = null)
     {
         $this->livenessType = $livenessType;
         $this->maxRetries = $maxRetries;
diff --git a/src/DocScan/Session/Create/ImportTokenBuilder.php b/src/DocScan/Session/Create/ImportTokenBuilder.php
index 84340213..b40dd9bf 100644
--- a/src/DocScan/Session/Create/ImportTokenBuilder.php
+++ b/src/DocScan/Session/Create/ImportTokenBuilder.php
@@ -10,7 +10,7 @@ class ImportTokenBuilder
 
     private int $ttl;
 
-    public function withTtl(int $ttl = null): ImportTokenBuilder
+    public function withTtl(?int $ttl = null): ImportTokenBuilder
     {
         $this->ttl = $ttl ?? self::DEFAULT_TTL;
 
diff --git a/src/DocScan/Session/Create/SdkConfig.php b/src/DocScan/Session/Create/SdkConfig.php
index a3c8086d..43c0498d 100644
--- a/src/DocScan/Session/Create/SdkConfig.php
+++ b/src/DocScan/Session/Create/SdkConfig.php
@@ -68,6 +68,21 @@ class SdkConfig implements \JsonSerializable
      */
     private $biometricConsentFlow;
 
+    /**
+     * @var string|null
+     */
+    private $darkMode;
+
+    /**
+     * @var string|null
+     */
+    private $primaryColourDarkMode;
+
+    /**
+     * @var string|null
+     */
+    private $brandId;
+
     /**
      * @param string|null $allowedCaptureMethods
      * @param string|null $primaryColour
@@ -81,6 +96,9 @@ class SdkConfig implements \JsonSerializable
      * @param bool|null $allowHandoff
      * @param array<string, int>|null $idDocumentTextDataExtractionRetriesConfig
      * @param string|null $biometricConsentFlow
+     * @param string|null $darkMode
+     * @param string|null $primaryColourDarkMode
+     * @param string|null $brandId
      */
     public function __construct(
         ?string $allowedCaptureMethods,
@@ -94,7 +112,10 @@ public function __construct(
         ?string $privacyPolicyUrl = null,
         ?bool $allowHandoff = null,
         ?array $idDocumentTextDataExtractionRetriesConfig = null,
-        ?string $biometricConsentFlow = null
+        ?string $biometricConsentFlow = null,
+        ?string $darkMode = null,
+        ?string $primaryColourDarkMode = null,
+        ?string $brandId = null
     ) {
         $this->allowedCaptureMethods = $allowedCaptureMethods;
         $this->primaryColour = $primaryColour;
@@ -110,6 +131,9 @@ public function __construct(
             $this->attemptsConfiguration = new AttemptsConfiguration($idDocumentTextDataExtractionRetriesConfig);
         }
         $this->biometricConsentFlow = $biometricConsentFlow;
+        $this->darkMode = $darkMode;
+        $this->primaryColourDarkMode = $primaryColourDarkMode;
+        $this->brandId = $brandId;
     }
 
     /**
@@ -129,7 +153,10 @@ public function jsonSerialize(): \stdClass
             'privacy_policy_url' => $this->getPrivacyPolicyUrl(),
             'allow_handoff' => $this->getAllowHandoff(),
             'attempts_configuration' => $this->getAttemptsConfiguration(),
-            'biometric_consent_flow' => $this->getBiometricConsentFlow()
+            'biometric_consent_flow' => $this->getBiometricConsentFlow(),
+            'dark_mode' => $this->getDarkMode(),
+            'primary_colour_dark_mode' => $this->getPrimaryColourDarkMode(),
+            'brand_id' => $this->getBrandId()
         ]);
     }
 
@@ -228,4 +255,28 @@ public function getBiometricConsentFlow(): ?string
     {
         return $this->biometricConsentFlow;
     }
+
+    /**
+     * @return string|null
+     */
+    public function getDarkMode(): ?string
+    {
+        return $this->darkMode;
+    }
+
+    /**
+     * @return string|null
+     */
+    public function getPrimaryColourDarkMode(): ?string
+    {
+        return $this->primaryColourDarkMode;
+    }
+
+    /**
+     * @return string|null
+     */
+    public function getBrandId(): ?string
+    {
+        return $this->brandId;
+    }
 }
diff --git a/src/DocScan/Session/Create/SdkConfigBuilder.php b/src/DocScan/Session/Create/SdkConfigBuilder.php
index acf30fcc..5a4661dd 100644
--- a/src/DocScan/Session/Create/SdkConfigBuilder.php
+++ b/src/DocScan/Session/Create/SdkConfigBuilder.php
@@ -71,6 +71,21 @@ class SdkConfigBuilder
      */
     private $biometricConsentFlow;
 
+    /**
+     * @var string|null
+     */
+    private $darkMode;
+
+    /**
+     * @var string|null
+     */
+    private $primaryColourDarkMode;
+
+    /**
+     * @var string|null
+     */
+    private $brandId;
+
     public function withAllowsCamera(): self
     {
         return $this->withAllowedCaptureMethod(self::CAMERA);
@@ -146,6 +161,7 @@ public function withBiometricConsentFlow(string $biometricConsentFlow): self
         $this->biometricConsentFlow = $biometricConsentFlow;
         return $this;
     }
+
     /**
      * Allows configuring the number of attempts permitted for text extraction on an ID document
      *
@@ -199,6 +215,41 @@ public function withIdDocumentTextExtractionGenericAttempts(int $genericRetries)
         return $this;
     }
 
+    public function withDarkMode(string $darkMode): self
+    {
+        $this->darkMode = $darkMode;
+        return $this;
+    }
+
+    public function withDarkModeOn(): self
+    {
+        $this->darkMode = "ON";
+        return $this;
+    }
+
+    public function withDarkModeOff(): self
+    {
+        $this->darkMode = "OFF";
+        return $this;
+    }
+
+    public function withDarkModeAuto(): self
+    {
+        $this->darkMode = "AUTO";
+        return $this;
+    }
+
+    public function withPrimaryColourDarkMode(string $primaryColourDarkMode): self
+    {
+        $this->primaryColourDarkMode = $primaryColourDarkMode;
+        return $this;
+    }
+
+    public function withBrandId(string $brandId): self
+    {
+        $this->brandId = $brandId;
+        return $this;
+    }
 
     public function build(): SdkConfig
     {
@@ -214,7 +265,10 @@ public function build(): SdkConfig
             $this->privacyPolicyUrl,
             $this->allowHandoff,
             $this->idDocumentTextDataExtractionRetriesConfig,
-            $this->biometricConsentFlow
+            $this->biometricConsentFlow,
+            $this->darkMode,
+            $this->primaryColourDarkMode,
+            $this->brandId
         );
     }
 }
diff --git a/src/DocScan/Session/Retrieve/CustomAccountWatchlistCaSearchConfigResponse.php b/src/DocScan/Session/Retrieve/CustomAccountWatchlistCaSearchConfigResponse.php
index efa7819d..6b95fd6c 100644
--- a/src/DocScan/Session/Retrieve/CustomAccountWatchlistCaSearchConfigResponse.php
+++ b/src/DocScan/Session/Retrieve/CustomAccountWatchlistCaSearchConfigResponse.php
@@ -35,7 +35,9 @@ public function __construct(array $searchConfig)
         $this->apiKey = $searchConfig['api_key'];
         $this->monitoring = $searchConfig['monitoring'];
         $this->clientRef = $searchConfig['client_ref'];
-        $this->tags = array_key_exists('tags', $searchConfig) ? json_decode($searchConfig['tags'], true) : [];
+        $this->tags = array_key_exists('tags', $searchConfig) && is_string($searchConfig['tags'])
+            ? json_decode($searchConfig['tags'], true)
+            : (array_key_exists('tags', $searchConfig) && is_array($searchConfig['tags']) ? $searchConfig['tags'] : []);
     }
 
     /**
diff --git a/src/Exception/ActivityDetailsException.php b/src/Exception/ActivityDetailsException.php
index 1913be81..d01f61ac 100644
--- a/src/Exception/ActivityDetailsException.php
+++ b/src/Exception/ActivityDetailsException.php
@@ -25,7 +25,7 @@ public function __construct(
         $message = "",
         ?ResponseInterface $response = null,
         ?array $responseBody = null,
-        \Throwable $previous = null
+        ?\Throwable $previous = null
     ) {
         parent::__construct($message, $response, $previous);
 
diff --git a/src/Exception/base/YotiException.php b/src/Exception/base/YotiException.php
index 8dde0005..b6a7d2e6 100644
--- a/src/Exception/base/YotiException.php
+++ b/src/Exception/base/YotiException.php
@@ -20,7 +20,7 @@ class YotiException extends \Exception
      * @param ResponseInterface|null $response
      * @param \Throwable|null $previous
      */
-    public function __construct($message = "", ?ResponseInterface $response = null, \Throwable $previous = null)
+    public function __construct($message = "", ?ResponseInterface $response = null, ?\Throwable $previous = null)
     {
         parent::__construct($this->formatMessage($message, $response), 0, $previous);
 
diff --git a/src/Http/Exception/NetworkException.php b/src/Http/Exception/NetworkException.php
index 0879d9f9..814871f7 100644
--- a/src/Http/Exception/NetworkException.php
+++ b/src/Http/Exception/NetworkException.php
@@ -19,7 +19,7 @@ class NetworkException extends ClientException implements NetworkExceptionInterf
     public function __construct(
         string $message,
         RequestInterface $request,
-        \Throwable $previous = null
+        ?\Throwable $previous = null
     ) {
         $this->setRequest($request);
         parent::__construct($message, 0, $previous);
diff --git a/src/Http/Exception/RequestException.php b/src/Http/Exception/RequestException.php
index 2ce34d5d..6c3a946c 100644
--- a/src/Http/Exception/RequestException.php
+++ b/src/Http/Exception/RequestException.php
@@ -19,7 +19,7 @@ class RequestException extends ClientException implements RequestExceptionInterf
     public function __construct(
         string $message,
         RequestInterface $request,
-        \Throwable $previous = null
+        ?\Throwable $previous = null
     ) {
         $this->setRequest($request);
         parent::__construct($message, 0, $previous);
diff --git a/src/Http/RequestBuilder.php b/src/Http/RequestBuilder.php
index 8afff19e..e2413181 100644
--- a/src/Http/RequestBuilder.php
+++ b/src/Http/RequestBuilder.php
@@ -73,9 +73,9 @@ class RequestBuilder
     private $multipartEntity;
 
     /**
-     * @param \Yoti\Util\Config $config
+     * @param \Yoti\Util\Config|null $config
      */
-    public function __construct(Config $config = null)
+    public function __construct(?Config $config = null)
     {
         $this->config = $config ?? new Config();
     }
diff --git a/src/Http/RequestSigner.php b/src/Http/RequestSigner.php
index 99bdff79..abf09fe0 100644
--- a/src/Http/RequestSigner.php
+++ b/src/Http/RequestSigner.php
@@ -26,7 +26,7 @@ public static function sign(
         PemFile $pemFile,
         string $endpoint,
         string $httpMethod,
-        Payload $payload = null
+        ?Payload $payload = null
     ): string {
         $messageToSign = "{$httpMethod}&$endpoint";
         if ($payload instanceof Payload) {
diff --git a/src/Identity/Content/ApplicationContent.php b/src/Identity/Content/ApplicationContent.php
index 8487fc4a..7c0d267f 100644
--- a/src/Identity/Content/ApplicationContent.php
+++ b/src/Identity/Content/ApplicationContent.php
@@ -10,7 +10,7 @@ class ApplicationContent
     private ?ApplicationProfile $profile;
     private ?ExtraData $extraData;
 
-    public function __construct(ApplicationProfile $profile = null, ExtraData $extraData = null)
+    public function __construct(?ApplicationProfile $profile = null, ?ExtraData $extraData = null)
     {
         $this->profile = $profile;
         $this->extraData = $extraData;
diff --git a/src/Identity/Content/Content.php b/src/Identity/Content/Content.php
index 9cf61c01..cef3ef37 100644
--- a/src/Identity/Content/Content.php
+++ b/src/Identity/Content/Content.php
@@ -9,7 +9,7 @@ class Content
     private ?string $profile;
     private ?string $extraData;
 
-    public function __construct(string $profile = null, string $extraData = null)
+    public function __construct(?string $profile = null, ?string $extraData = null)
     {
         $this->profile = $profile;
         $this->extraData = $extraData;
diff --git a/src/Identity/Content/UserContent.php b/src/Identity/Content/UserContent.php
index a32c2dfd..a69e24fd 100644
--- a/src/Identity/Content/UserContent.php
+++ b/src/Identity/Content/UserContent.php
@@ -10,7 +10,7 @@ class UserContent
     private ?UserProfile $profile;
     private ?ExtraData $extraData;
 
-    public function __construct(UserProfile $profile = null, ExtraData $extraData = null)
+    public function __construct(?UserProfile $profile = null, ?ExtraData $extraData = null)
     {
         $this->profile = $profile;
         $this->extraData = $extraData;
diff --git a/src/Identity/Policy/PolicyBuilder.php b/src/Identity/Policy/PolicyBuilder.php
index a3b8f479..8ad89aaa 100644
--- a/src/Identity/Policy/PolicyBuilder.php
+++ b/src/Identity/Policy/PolicyBuilder.php
@@ -51,8 +51,8 @@ public function withWantedAttribute(WantedAttribute $wantedAttribute): self
      */
     public function withWantedAttributeByName(
         string $name,
-        array $constraints = null,
-        bool $acceptSelfAsserted = null
+        ?array $constraints = null,
+        ?bool $acceptSelfAsserted = null
     ): self {
         $wantedAttributeBuilder = (new WantedAttributeBuilder())
             ->withName($name);
@@ -71,7 +71,7 @@ public function withWantedAttributeByName(
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withFamilyName(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withFamilyName(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_FAMILY_NAME,
@@ -83,7 +83,7 @@ public function withFamilyName(array $constraints = null, bool $acceptSelfAssert
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withGivenNames(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withGivenNames(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_GIVEN_NAMES,
@@ -95,7 +95,7 @@ public function withGivenNames(array $constraints = null, bool $acceptSelfAssert
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withFullName(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withFullName(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_FULL_NAME,
@@ -107,7 +107,7 @@ public function withFullName(array $constraints = null, bool $acceptSelfAsserted
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withDateOfBirth(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withDateOfBirth(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_DATE_OF_BIRTH,
@@ -119,7 +119,7 @@ public function withDateOfBirth(array $constraints = null, bool $acceptSelfAsser
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withAgeOver(int $age, array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withAgeOver(int $age, ?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withAgeDerivedAttribute(
             UserProfile::AGE_OVER . $age,
@@ -131,7 +131,7 @@ public function withAgeOver(int $age, array $constraints = null, bool $acceptSel
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withAgeUnder(int $age, array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withAgeUnder(int $age, ?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withAgeDerivedAttribute(
             UserProfile::AGE_UNDER . $age,
@@ -145,8 +145,8 @@ public function withAgeUnder(int $age, array $constraints = null, bool $acceptSe
      */
     public function withAgeDerivedAttribute(
         string $derivation,
-        array $constraints = null,
-        bool $acceptSelfAsserted = null
+        ?array $constraints = null,
+        ?bool $acceptSelfAsserted = null
     ): self {
         $wantedAttributeBuilder = (new WantedAttributeBuilder())
             ->withName(UserProfile::ATTR_DATE_OF_BIRTH)
@@ -166,7 +166,7 @@ public function withAgeDerivedAttribute(
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withGender(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withGender(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_GENDER,
@@ -178,7 +178,7 @@ public function withGender(array $constraints = null, bool $acceptSelfAsserted =
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withPostalAddress(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withPostalAddress(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_POSTAL_ADDRESS,
@@ -190,7 +190,7 @@ public function withPostalAddress(array $constraints = null, bool $acceptSelfAss
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withStructuredPostalAddress(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withStructuredPostalAddress(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_STRUCTURED_POSTAL_ADDRESS,
@@ -202,7 +202,7 @@ public function withStructuredPostalAddress(array $constraints = null, bool $acc
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withNationality(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withNationality(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_NATIONALITY,
@@ -214,7 +214,7 @@ public function withNationality(array $constraints = null, bool $acceptSelfAsser
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withPhoneNumber(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withPhoneNumber(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_PHONE_NUMBER,
@@ -226,7 +226,7 @@ public function withPhoneNumber(array $constraints = null, bool $acceptSelfAsser
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withSelfie(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withSelfie(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_SELFIE,
@@ -238,7 +238,7 @@ public function withSelfie(array $constraints = null, bool $acceptSelfAsserted =
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withDocumentDetails(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withDocumentDetails(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_DOCUMENT_DETAILS,
@@ -250,7 +250,7 @@ public function withDocumentDetails(array $constraints = null, bool $acceptSelfA
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withDocumentImages(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withDocumentImages(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_DOCUMENT_IMAGES,
@@ -262,7 +262,7 @@ public function withDocumentImages(array $constraints = null, bool $acceptSelfAs
     /**
      * @param Constraint[]|null $constraints
      */
-    public function withEmail(array $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withEmail(?array $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_EMAIL_ADDRESS,
diff --git a/src/Identity/Policy/WantedAttribute.php b/src/Identity/Policy/WantedAttribute.php
index dc34da79..47005af1 100644
--- a/src/Identity/Policy/WantedAttribute.php
+++ b/src/Identity/Policy/WantedAttribute.php
@@ -29,10 +29,10 @@ class WantedAttribute implements \JsonSerializable
      */
     public function __construct(
         string $name,
-        string $derivation = null,
+        ?string $derivation = null,
         bool $optional = false,
-        bool $acceptSelfAsserted = null,
-        array $constraints = null
+        ?bool $acceptSelfAsserted = null,
+        ?array $constraints = null
     ) {
         Validation::notEmptyString($name, 'name');
         $this->name = $name;
diff --git a/src/Identity/ReceiptBuilder.php b/src/Identity/ReceiptBuilder.php
index 0851a088..1ec378f2 100644
--- a/src/Identity/ReceiptBuilder.php
+++ b/src/Identity/ReceiptBuilder.php
@@ -42,14 +42,14 @@ public function withSessionId(string $sessionId): self
         return $this;
     }
 
-    public function withRememberMeId(string $rememberMeId = null): self
+    public function withRememberMeId(?string $rememberMeId = null): self
     {
         $this->rememberMeId = $rememberMeId;
 
         return $this;
     }
 
-    public function withParentRememberMeId(string $parentRememberMeId = null): self
+    public function withParentRememberMeId(?string $parentRememberMeId = null): self
     {
         $this->parentRememberMeId = $parentRememberMeId;
 
@@ -63,28 +63,28 @@ public function withTimestamp(\DateTime $timestamp): self
         return $this;
     }
 
-    public function withApplicationContent(ApplicationProfile $profile, ExtraData $extraData = null): self
+    public function withApplicationContent(ApplicationProfile $profile, ?ExtraData $extraData = null): self
     {
         $this->applicationContent = new ApplicationContent($profile, $extraData);
 
         return $this;
     }
 
-    public function withUserContent(UserProfile $profile = null, ExtraData $extraData = null): self
+    public function withUserContent(?UserProfile $profile = null, ?ExtraData $extraData = null): self
     {
         $this->userContent = new UserContent($profile, $extraData);
 
         return $this;
     }
 
-    public function withError(string $error = null): self
+    public function withError(?string $error = null): self
     {
         $this->error = $error;
 
         return $this;
     }
 
-    public function withErrorReason(ErrorReason $errorReason = null): self
+    public function withErrorReason(?ErrorReason $errorReason = null): self
     {
         $this->errorReason = $errorReason;
 
diff --git a/src/Identity/ReceiptParser.php b/src/Identity/ReceiptParser.php
index 904ef7b7..39fae9ee 100644
--- a/src/Identity/ReceiptParser.php
+++ b/src/Identity/ReceiptParser.php
@@ -21,7 +21,7 @@ class ReceiptParser
      */
     private $logger;
 
-    public function __construct(LoggerInterface $logger = null)
+    public function __construct(?LoggerInterface $logger = null)
     {
         $this->logger = $logger ?? new Logger();
     }
diff --git a/src/Profile/Attribute.php b/src/Profile/Attribute.php
index 1117f728..39f1d8b2 100644
--- a/src/Profile/Attribute.php
+++ b/src/Profile/Attribute.php
@@ -36,7 +36,7 @@ class Attribute
      * @param Anchor[] $anchors
      * @param string|null $id
      */
-    public function __construct(string $name, $value, array $anchors, string $id = null)
+    public function __construct(string $name, $value, array $anchors, ?string $id = null)
     {
         $this->name = $name;
         $this->value = $value;
diff --git a/src/Profile/ExtraData/AttributeIssuanceDetails.php b/src/Profile/ExtraData/AttributeIssuanceDetails.php
index 019350c6..31d6e9ca 100644
--- a/src/Profile/ExtraData/AttributeIssuanceDetails.php
+++ b/src/Profile/ExtraData/AttributeIssuanceDetails.php
@@ -25,10 +25,10 @@ class AttributeIssuanceDetails
 
     /**
      * @param string $token
-     * @param \DateTime $expiryDate
+     * @param \DateTime|null $expiryDate
      * @param \Yoti\Profile\ExtraData\AttributeDefinition[] $issuingAttributes
      */
-    public function __construct(string $token, \DateTime $expiryDate = null, array $issuingAttributes = [])
+    public function __construct(string $token, ?\DateTime $expiryDate = null, array $issuingAttributes = [])
     {
         $this->token = $token;
 
diff --git a/src/Profile/Util/Attribute/AnchorConverter.php b/src/Profile/Util/Attribute/AnchorConverter.php
index a13d6147..93f9b130 100644
--- a/src/Profile/Util/Attribute/AnchorConverter.php
+++ b/src/Profile/Util/Attribute/AnchorConverter.php
@@ -60,8 +60,31 @@ private static function decodeAnchorValue(string $extEncodedValue): string
     {
         $encodedBER = ASN1::extractBER($extEncodedValue);
         $decodedValArr = ASN1::decodeBER($encodedBER);
+
         if (isset($decodedValArr[0]['content'][0]['content'])) {
-            return $decodedValArr[0]['content'][0]['content'];
+            $value = $decodedValArr[0]['content'][0]['content'];
+
+            if (!is_string($value)) {
+                return '';
+            }
+
+            $detectionOrder = mb_detect_order();
+            $encoding = mb_detect_encoding($value, is_array($detectionOrder) ? $detectionOrder : null, true);
+
+            if (is_string($encoding)) {
+                if ($encoding !== 'UTF-8') {
+                    // PHPStan implies $value is string, $encoding is valid string, so result is string.
+                    return mb_convert_encoding($value, 'UTF-8', $encoding);
+                }
+                // It is UTF-8
+                return $value;
+            } else { // $encoding is false (detection failed)
+                if (!mb_check_encoding($value, 'UTF-8')) {
+                    // PHPStan implies $value is string, so result is string.
+                    return mb_convert_encoding($value, 'UTF-8', 'ISO-8859-1');
+                }
+                return $value; // It's valid UTF-8 despite detection failing
+            }
         }
         return '';
     }
@@ -108,16 +131,28 @@ private static function convertCertToX509(string $certificate): \stdClass
         $X509 = new X509();
         $X509Data = $X509->loadX509($certificate);
 
-        /** We need because of new 3.0 version phpseclib @link https://github.com/phpseclib/phpseclib/issues/1738 */
         array_walk_recursive($X509Data, function (&$item): void {
-            if (is_string($item) && mb_detect_encoding($item) != 'ASCII') {
-                $item = base64_encode($item);
+            if (is_string($item)) {
+                $detectionOrder = mb_detect_order();
+                $encoding = mb_detect_encoding($item, is_array($detectionOrder) ? $detectionOrder : null, true);
+
+                if (is_string($encoding)) {
+                    if ($encoding !== 'UTF-8' && $encoding !== 'ASCII') {
+                        // PHPStan implies $item is string, $encoding is valid string, so result is string.
+                        // The 'else' branch for base64_encode was deemed unreachable by PHPStan.
+                        $item = mb_convert_encoding($item, 'UTF-8', $encoding);
+                    }
+                    // If $encoding is 'UTF-8' or 'ASCII', $item is left as is.
+                } else { // $encoding is false (detection failed)
+                    if (!mb_check_encoding($item, 'UTF-8') && !mb_check_encoding($item, 'ASCII')) {
+                        $item = base64_encode($item);
+                    }
+                    // If it's valid UTF-8/ASCII despite detection failing, $item is left as is.
+                }
             }
         });
 
         $decodedX509Data = Json::decode(Json::encode(Json::convertFromLatin1ToUtf8Recursively($X509Data)), false);
-        // Ensure serial number is cast to string.
-        // @see \phpseclib\Math\BigInteger::__toString()
         $decodedX509Data
             ->tbsCertificate
             ->serialNumber
diff --git a/src/ShareUrl/Policy/DynamicPolicyBuilder.php b/src/ShareUrl/Policy/DynamicPolicyBuilder.php
index 4d3ba083..cf395be2 100644
--- a/src/ShareUrl/Policy/DynamicPolicyBuilder.php
+++ b/src/ShareUrl/Policy/DynamicPolicyBuilder.php
@@ -77,8 +77,8 @@ public function withWantedAttribute(WantedAttribute $wantedAttribute): self
      */
     public function withWantedAttributeByName(
         string $name,
-        Constraints $constraints = null,
-        bool $acceptSelfAsserted = null
+        ?Constraints $constraints = null,
+        ?bool $acceptSelfAsserted = null
     ): self {
         $wantedAttributeBuilder = (new WantedAttributeBuilder())
             ->withName($name);
@@ -100,7 +100,7 @@ public function withWantedAttributeByName(
      *
      * @return $this
      */
-    public function withFamilyName(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withFamilyName(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_FAMILY_NAME,
@@ -115,7 +115,7 @@ public function withFamilyName(Constraints $constraints = null, bool $acceptSelf
      *
      * @return self
      */
-    public function withGivenNames(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withGivenNames(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_GIVEN_NAMES,
@@ -130,7 +130,7 @@ public function withGivenNames(Constraints $constraints = null, bool $acceptSelf
      *
      * @return self
      */
-    public function withFullName(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withFullName(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_FULL_NAME,
@@ -145,7 +145,7 @@ public function withFullName(Constraints $constraints = null, bool $acceptSelfAs
      *
      * @return $this
      */
-    public function withDateOfBirth(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withDateOfBirth(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_DATE_OF_BIRTH,
@@ -161,7 +161,7 @@ public function withDateOfBirth(Constraints $constraints = null, bool $acceptSel
      *
      * @return $this
      */
-    public function withAgeOver(int $age, Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withAgeOver(int $age, ?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withAgeDerivedAttribute(
             UserProfile::AGE_OVER . (string) $age,
@@ -177,7 +177,7 @@ public function withAgeOver(int $age, Constraints $constraints = null, bool $acc
      *
      * @return $this
      */
-    public function withAgeUnder(int $age, Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withAgeUnder(int $age, ?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withAgeDerivedAttribute(
             UserProfile::AGE_UNDER . (string) $age,
@@ -195,8 +195,8 @@ public function withAgeUnder(int $age, Constraints $constraints = null, bool $ac
      */
     public function withAgeDerivedAttribute(
         string $derivation,
-        Constraints $constraints = null,
-        bool $acceptSelfAsserted = null
+        ?Constraints $constraints = null,
+        ?bool $acceptSelfAsserted = null
     ): self {
         $wantedAttributeBuilder = (new WantedAttributeBuilder())
             ->withName(UserProfile::ATTR_DATE_OF_BIRTH)
@@ -216,7 +216,7 @@ public function withAgeDerivedAttribute(
      *
      * @return $this
      */
-    public function withGender(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withGender(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_GENDER,
@@ -231,7 +231,7 @@ public function withGender(Constraints $constraints = null, bool $acceptSelfAsse
      *
      * @return $this
      */
-    public function withPostalAddress(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withPostalAddress(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_POSTAL_ADDRESS,
@@ -246,8 +246,10 @@ public function withPostalAddress(Constraints $constraints = null, bool $acceptS
      *
      * @return $this
      */
-    public function withStructuredPostalAddress(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
-    {
+    public function withStructuredPostalAddress(
+        ?Constraints $constraints = null,
+        ?bool $acceptSelfAsserted = null
+    ): self {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_STRUCTURED_POSTAL_ADDRESS,
             $constraints,
@@ -261,7 +263,7 @@ public function withStructuredPostalAddress(Constraints $constraints = null, boo
      *
      * @return $this
      */
-    public function withNationality(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withNationality(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_NATIONALITY,
@@ -276,7 +278,7 @@ public function withNationality(Constraints $constraints = null, bool $acceptSel
      *
      * @return $this
      */
-    public function withPhoneNumber(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withPhoneNumber(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_PHONE_NUMBER,
@@ -291,7 +293,7 @@ public function withPhoneNumber(Constraints $constraints = null, bool $acceptSel
      *
      * @return $this
      */
-    public function withSelfie(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withSelfie(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_SELFIE,
@@ -306,7 +308,7 @@ public function withSelfie(Constraints $constraints = null, bool $acceptSelfAsse
      *
      * @return $this
      */
-    public function withDocumentDetails(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withDocumentDetails(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_DOCUMENT_DETAILS,
@@ -321,7 +323,7 @@ public function withDocumentDetails(Constraints $constraints = null, bool $accep
      *
      * @return $this
      */
-    public function withDocumentImages(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withDocumentImages(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_DOCUMENT_IMAGES,
@@ -336,7 +338,7 @@ public function withDocumentImages(Constraints $constraints = null, bool $accept
      *
      * @return $this
      */
-    public function withEmail(Constraints $constraints = null, bool $acceptSelfAsserted = null): self
+    public function withEmail(?Constraints $constraints = null, ?bool $acceptSelfAsserted = null): self
     {
         return $this->withWantedAttributeByName(
             UserProfile::ATTR_EMAIL_ADDRESS,
@@ -411,7 +413,7 @@ public function withIdentityProfileRequirements($identityProfileRequirements): s
      * @param object $advancedIdentityProfileRequirements
      * @return $this
      */
-    public function withAdvancedIdentityProfileRequirements($advancedIdentityProfileRequirements): self
+    public function withAdvIdentityProfileReqs($advancedIdentityProfileRequirements): self
     {
         $this->advancedIdentityProfileRequirements = $advancedIdentityProfileRequirements;
         return $this;
diff --git a/src/ShareUrl/Policy/WantedAttribute.php b/src/ShareUrl/Policy/WantedAttribute.php
index a5b0f2ed..d176070a 100644
--- a/src/ShareUrl/Policy/WantedAttribute.php
+++ b/src/ShareUrl/Policy/WantedAttribute.php
@@ -32,17 +32,24 @@ class WantedAttribute implements \JsonSerializable
      */
     private $acceptSelfAsserted;
 
+    /**
+     * @var bool|null
+     */
+    private $optional;
+
     /**
      * @param string $name
      * @param string $derivation
      * @param bool $acceptSelfAsserted
      * @param \Yoti\ShareUrl\Policy\Constraints $constraints
+     * @param bool $optional
      */
     public function __construct(
         string $name,
-        string $derivation = null,
-        bool $acceptSelfAsserted = null,
-        Constraints $constraints = null
+        ?string $derivation = null,
+        ?bool $acceptSelfAsserted = null,
+        ?Constraints $constraints = null,
+        ?bool $optional = null
     ) {
         Validation::notEmptyString($name, 'name');
         $this->name = $name;
@@ -50,6 +57,7 @@ public function __construct(
         $this->derivation = $derivation;
         $this->acceptSelfAsserted = $acceptSelfAsserted;
         $this->constraints = $constraints;
+        $this->optional = $optional;
     }
 
     /**
@@ -97,6 +105,14 @@ public function getAcceptSelfAsserted(): ?bool
         return $this->acceptSelfAsserted;
     }
 
+    /**
+     * @return bool|null
+     */
+    public function getOptional(): ?bool
+    {
+        return $this->optional;
+    }
+
     /**
      * @inheritDoc
      *
@@ -106,7 +122,7 @@ public function jsonSerialize(): array
     {
         $json = [
             'name' => $this->getName(),
-            'optional' => false,
+            'optional' => $this->getOptional(),
         ];
 
         if ($this->getDerivation() !== null) {
@@ -121,6 +137,12 @@ public function jsonSerialize(): array
             $json['accept_self_asserted'] = $this->getAcceptSelfAsserted();
         }
 
+        if ($this->getOptional() !== null) {
+            $json['optional'] = $this->getOptional();
+        }
+
+
+
         return $json;
     }
 
diff --git a/src/ShareUrl/Policy/WantedAttributeBuilder.php b/src/ShareUrl/Policy/WantedAttributeBuilder.php
index 37f381e7..9995cfdb 100644
--- a/src/ShareUrl/Policy/WantedAttributeBuilder.php
+++ b/src/ShareUrl/Policy/WantedAttributeBuilder.php
@@ -29,6 +29,10 @@ class WantedAttributeBuilder
      */
     private $acceptSelfAsserted;
 
+    /**
+     * @var bool|null
+     */
+    private $optional = false;
     /**
      * @param string $name
      *
@@ -73,6 +77,16 @@ public function withAcceptSelfAsserted(?bool $acceptSelfAsserted = true): self
         return $this;
     }
 
+    /**
+     * @param bool $optional
+     *
+     * @return $this
+     */
+    public function withOptional(?bool $optional = false): self
+    {
+        $this->optional = $optional;
+        return $this;
+    }
     /**
      * @return \Yoti\ShareUrl\Policy\WantedAttribute
      */
@@ -82,7 +96,8 @@ public function build(): WantedAttribute
             $this->name,
             $this->derivation,
             $this->acceptSelfAsserted,
-            $this->constraints
+            $this->constraints,
+            $this->optional
         );
     }
 }
diff --git a/src/Util/Json.php b/src/Util/Json.php
index 8be63f78..81f7bdb7 100644
--- a/src/Util/Json.php
+++ b/src/Util/Json.php
@@ -65,7 +65,7 @@ private static function validate(): void
     public static function convertFromLatin1ToUtf8Recursively($dat)
     {
         if (is_string($dat)) {
-            return utf8_encode($dat);
+            return mb_convert_encoding($dat, 'UTF-8', 'ISO-8859-1');
         } elseif (is_array($dat)) {
             $ret = [];
             foreach ($dat as $i => $d) {
diff --git a/tests/Aml/ResultTest.php b/tests/Aml/ResultTest.php
index 76dd42d0..86f83eaf 100644
--- a/tests/Aml/ResultTest.php
+++ b/tests/Aml/ResultTest.php
@@ -21,6 +21,11 @@ class ResultTest extends TestCase
      */
     public $amlResult;
 
+    /**
+     * @var \PHPUnit\Framework\MockObject\MockObject&\Psr\Http\Message\ResponseInterface
+     */
+    private $responseMock;
+
     public function setup(): void
     {
         $this->responseMock = $this->createMock(ResponseInterface::class);
diff --git a/tests/DocScan/Session/Create/SdkConfigBuilderTest.php b/tests/DocScan/Session/Create/SdkConfigBuilderTest.php
index 3c84f5d2..846f2433 100644
--- a/tests/DocScan/Session/Create/SdkConfigBuilderTest.php
+++ b/tests/DocScan/Session/Create/SdkConfigBuilderTest.php
@@ -23,7 +23,9 @@ class SdkConfigBuilderTest extends TestCase
     private const SOME_CATEGORY = 'someCategory';
     private const SOME_NUMBER_RETRIES = 5;
     private const SOME_BIOMETRIC_CONSENT_FLOW = 'someBiometricConsentFlow';
-
+    private const SOME_DARK_MODE = 'someDarkMode';
+    private const SOME_PRIMARY_COLOUR_DARK_MODE = 'somePrimaryColourDarkMode';
+    private const SOME_BRAND_ID = 'someBrandId';
 
     /**
      * @test
@@ -38,6 +40,7 @@ class SdkConfigBuilderTest extends TestCase
      * @covers ::withErrorUrl
      * @covers ::withPrivacyPolicyUrl
      * @covers ::withAllowHandoff
+     * @covers ::withBrandId
      * @covers \Yoti\DocScan\Session\Create\SdkConfig::__construct
      * @covers \Yoti\DocScan\Session\Create\SdkConfig::getAllowedCaptureMethods
      * @covers \Yoti\DocScan\Session\Create\SdkConfig::getPrimaryColour
@@ -49,6 +52,9 @@ class SdkConfigBuilderTest extends TestCase
      * @covers \Yoti\DocScan\Session\Create\SdkConfig::getErrorUrl
      * @covers \Yoti\DocScan\Session\Create\SdkConfig::getPrivacyPolicyUrl
      * @covers \Yoti\DocScan\Session\Create\SdkConfig::getAllowHandoff
+     * @covers \Yoti\DocScan\Session\Create\SdkConfig::getDarkMode
+     * @covers \Yoti\DocScan\Session\Create\SdkConfig::getPrimaryColourDarkMode
+     * @covers \Yoti\DocScan\Session\Create\SdkConfig::getBrandId
      */
     public function shouldCorrectlyBuildSdkConfig()
     {
@@ -63,6 +69,10 @@ public function shouldCorrectlyBuildSdkConfig()
             ->withErrorUrl(self::SOME_ERROR_URL)
             ->withPrivacyPolicyUrl(self::SOME_PRIVACY_POLICY_URL)
             ->withAllowHandoff(true)
+            ->withBiometricConsentFlow(self::SOME_BIOMETRIC_CONSENT_FLOW)
+            ->withDarkMode(self::SOME_DARK_MODE)
+            ->withPrimaryColourDarkMode(self::SOME_PRIMARY_COLOUR_DARK_MODE)
+            ->withBrandId(self::SOME_BRAND_ID)
             ->build();
 
         $this->assertEquals(self::SOME_CAPTURE_METHOD, $result->getAllowedCaptureMethods());
@@ -74,7 +84,11 @@ public function shouldCorrectlyBuildSdkConfig()
         $this->assertEquals(self::SOME_SUCCESS_URL, $result->getSuccessUrl());
         $this->assertEquals(self::SOME_ERROR_URL, $result->getErrorUrl());
         $this->assertEquals(self::SOME_PRIVACY_POLICY_URL, $result->getPrivacyPolicyUrl());
+        $this->assertEquals(self::SOME_BIOMETRIC_CONSENT_FLOW, $result->getBiometricConsentFlow());
         $this->assertTrue($result->getAllowHandoff());
+        $this->assertEquals(self::SOME_DARK_MODE, $result->getDarkMode());
+        $this->assertEquals(self::SOME_PRIMARY_COLOUR_DARK_MODE, $result->getPrimaryColourDarkMode());
+        $this->assertEquals(self::SOME_BRAND_ID, $result->getBrandId());
     }
 
     /**
@@ -121,6 +135,8 @@ public function shouldProduceTheCorrectJsonString()
             ->withPrivacyPolicyUrl(self::SOME_PRIVACY_POLICY_URL)
             ->withAllowHandoff(true)
             ->withBiometricConsentFlow(self::SOME_BIOMETRIC_CONSENT_FLOW)
+            ->withPrimaryColourDarkMode(self::SOME_PRIMARY_COLOUR_DARK_MODE)
+            ->withDarkMode(self::SOME_DARK_MODE)
             ->build();
 
         $expected = [
@@ -134,7 +150,9 @@ public function shouldProduceTheCorrectJsonString()
             'error_url' => self::SOME_ERROR_URL,
             'privacy_policy_url' => self::SOME_PRIVACY_POLICY_URL,
             'allow_handoff' => true,
-            'biometric_consent_flow' => self::SOME_BIOMETRIC_CONSENT_FLOW
+            'biometric_consent_flow' => self::SOME_BIOMETRIC_CONSENT_FLOW,
+            'dark_mode' => self::SOME_DARK_MODE,
+            'primary_colour_dark_mode' => self::SOME_PRIMARY_COLOUR_DARK_MODE
         ];
 
         $this->assertJsonStringEqualsJsonString(json_encode($expected), json_encode($result));
@@ -291,4 +309,43 @@ public function attemptsConfigurationShouldAllowMultipleCategories(): void
             ->getIdDocumentTextDataExtraction()
         );
     }
+
+    /**
+     * @test
+     * @covers ::withDarkModeAuto
+     */
+    public function shouldSetCorrectValueWithDarkModeAuto()
+    {
+        $result = (new SdkConfigBuilder())
+            ->withDarkModeAuto()
+            ->build();
+
+        $this->assertEquals('AUTO', $result->getDarkMode());
+    }
+
+    /**
+     * @test
+     * @covers ::withDarkModeOn
+     */
+    public function shouldSetCorrectValueWithDarkModeOn()
+    {
+        $result = (new SdkConfigBuilder())
+            ->withDarkModeOn()
+            ->build();
+
+        $this->assertEquals('ON', $result->getDarkMode());
+    }
+
+    /**
+     * @test
+     * @covers ::withDarkModeOff
+     */
+    public function shouldSetCorrectValueWithDarkModeOff()
+    {
+        $result = (new SdkConfigBuilder())
+            ->withDarkModeOff()
+            ->build();
+
+        $this->assertEquals('OFF', $result->getDarkMode());
+    }
 }
diff --git a/tests/Profile/BaseProfileTest.php b/tests/Profile/BaseProfileTest.php
index 71fce4bb..20c7b122 100644
--- a/tests/Profile/BaseProfileTest.php
+++ b/tests/Profile/BaseProfileTest.php
@@ -138,7 +138,7 @@ public function testGetAttributeById()
 
         $givenNamesAttribute = new ProtobufAttribute([
             'name' => self::SOME_ATTRIBUTE,
-            'value' => utf8_decode('Alan'),
+            'value' => mb_convert_encoding('Alan', 'ISO-8859-1', 'UTF-8'),
             'content_type' => self::CONTENT_TYPE_STRING,
         ]);
         $newAttribute = AttributeConverter::convertToYotiAttribute($givenNamesAttribute);
diff --git a/tests/Profile/Util/EncryptedDataTest.php b/tests/Profile/Util/EncryptedDataTest.php
index 1680c9a8..4d1e8741 100644
--- a/tests/Profile/Util/EncryptedDataTest.php
+++ b/tests/Profile/Util/EncryptedDataTest.php
@@ -28,6 +28,11 @@ class EncrypedDataTest extends TestCase
      */
     private $wrappedKey;
 
+    /**
+     * @var \Yoti\Protobuf\Compubapi\EncryptedData
+     */
+    private $encryptedDataProto;
+
     /**
      * Setup test data.
      */
diff --git a/tests/ShareUrl/Policy/DynamicPolicyBuilderTest.php b/tests/ShareUrl/Policy/DynamicPolicyBuilderTest.php
index 0980b58e..0c1680a6 100644
--- a/tests/ShareUrl/Policy/DynamicPolicyBuilderTest.php
+++ b/tests/ShareUrl/Policy/DynamicPolicyBuilderTest.php
@@ -719,7 +719,7 @@ public function testWithAdvancedIdentityProfileRequirements()
         ];
 
         $dynamicPolicy = (new DynamicPolicyBuilder())
-            ->withAdvancedIdentityProfileRequirements($advancedIdentityProfileSample)
+            ->withAdvIdentityProfileReqs($advancedIdentityProfileSample)
             ->build();
 
         $this->assertEquals(json_encode($expectedWantedAttributeData), json_encode($dynamicPolicy));
diff --git a/tests/ShareUrl/Policy/WantedAttributeBuilderTest.php b/tests/ShareUrl/Policy/WantedAttributeBuilderTest.php
index 5abb542e..2b1c20f3 100644
--- a/tests/ShareUrl/Policy/WantedAttributeBuilderTest.php
+++ b/tests/ShareUrl/Policy/WantedAttributeBuilderTest.php
@@ -32,6 +32,7 @@ public function testBuild()
         $wantedAttribute = (new WantedAttributeBuilder())
             ->withName($someName)
             ->withDerivation($someDerivation)
+            ->withOptional(false)
             ->build();
 
         $expectedJsonData = [
@@ -91,6 +92,7 @@ public function testAcceptSelfAsserted()
         $wantedAttributeDefault = (new WantedAttributeBuilder())
             ->withName($someName)
             ->withAcceptSelfAsserted()
+            ->withOptional(false)
             ->build();
 
         $this->assertEquals(json_encode($expectedJsonData), json_encode($wantedAttributeDefault));
@@ -124,6 +126,7 @@ public function testWithoutAcceptSelfAsserted()
         $wantedAttribute = (new WantedAttributeBuilder())
             ->withName($someName)
             ->withAcceptSelfAsserted(false)
+            ->withOptional(false)
             ->build();
 
         $this->assertEquals(json_encode($expectedJsonData), json_encode($wantedAttribute));
@@ -149,6 +152,7 @@ public function testWithConstraints()
 
         $wantedAttribute = (new WantedAttributeBuilder())
             ->withName($someName)
+            ->withOptional(false)
             ->withConstraints($constraints)
             ->build();
 
diff --git a/tests/Util/JsonTest.php b/tests/Util/JsonTest.php
index df232c6e..30a9b29b 100644
--- a/tests/Util/JsonTest.php
+++ b/tests/Util/JsonTest.php
@@ -81,18 +81,27 @@ public function testWithoutNullValues()
      */
     public function testConvertFromLatin1ToUtf8Recursively()
     {
-        $latin1String = utf8_decode('éàê');
-        $latin1Array = [utf8_decode('éàê'), utf8_decode('çî')];
-        $nestedLatin1Array = [utf8_decode('éàê'), [utf8_decode('çî'), utf8_decode('üñ')]];
+        $latin1String = mb_convert_encoding('éàê', 'ISO-8859-1', 'UTF-8');
+        $latin1Array = [
+            mb_convert_encoding('éàê', 'ISO-8859-1', 'UTF-8'),
+            mb_convert_encoding('çî', 'ISO-8859-1', 'UTF-8')
+        ];
+        $nestedLatin1Array = [
+            mb_convert_encoding('éàê', 'ISO-8859-1', 'UTF-8'),
+            [
+                mb_convert_encoding('çî', 'ISO-8859-1', 'UTF-8'),
+                mb_convert_encoding('üñ', 'ISO-8859-1', 'UTF-8')
+            ]
+        ];
 
         $latin1Object = new \stdClass();
-        $latin1Object->property1 = utf8_decode('éàê');
-        $latin1Object->property2 = utf8_decode('çî');
+        $latin1Object->property1 = mb_convert_encoding('éàê', 'ISO-8859-1', 'UTF-8');
+        $latin1Object->property2 = mb_convert_encoding('çî', 'ISO-8859-1', 'UTF-8');
 
         $nestedLatin1Object = new \stdClass();
-        $nestedLatin1Object->property = utf8_decode('çî');
+        $nestedLatin1Object->property = mb_convert_encoding('çî', 'ISO-8859-1', 'UTF-8');
         $latin1ObjectWithNestedObject = new \stdClass();
-        $latin1ObjectWithNestedObject->property1 = utf8_decode('éàê');
+        $latin1ObjectWithNestedObject->property1 = mb_convert_encoding('éàê', 'ISO-8859-1', 'UTF-8');
         $latin1ObjectWithNestedObject->property2 = $nestedLatin1Object;
 
         $this->assertSame('éàê', Json::convertFromLatin1ToUtf8Recursively($latin1String));