diff --git a/composer.json b/composer.json
index 40ebdeb5..f71e437f 100644
--- a/composer.json
+++ b/composer.json
@@ -12,6 +12,7 @@
         "sage pay",
         "sagepay"
     ],
+
     "homepage": "https://github.com/thephpleague/omnipay-sagepay",
     "license": "MIT",
     "authors": [
@@ -34,7 +35,7 @@
         }
     },
     "require": {
-        "php": "^5.6|^7",
+        "php": "^5.6|^7|^8",
         "omnipay/common": "~3.0"
     },
     "require-dev": {
diff --git a/src/Message/AbstractRequest.php b/src/Message/AbstractRequest.php
index 31f02334..a7c8106f 100644
--- a/src/Message/AbstractRequest.php
+++ b/src/Message/AbstractRequest.php
@@ -17,6 +17,34 @@ abstract class AbstractRequest extends OmnipayAbstractRequest implements Constan
 {
     use GatewayParamsTrait;
 
+    /**
+     * Flag whether customer's browser can run javascript.
+     */
+    const BROWSER_JAVASCRIPT_YES   = 1;
+    const BROWSER_JAVASCRIPT_NO    = 0;
+
+    /**
+     * Fallback browser language
+     */
+    const BROWSER_LANGUAGE = 'en-GB';
+
+    /**
+     * Dimensions of the challenge window to be displayed to the cardholder.
+     *
+     * 01 = 250 x 400
+     * 02 = 390 x 400
+     * 03 = 500 x 600
+     * 04 = 600 x 400
+     * 05 = Full screen
+     *
+     * @var string
+     */
+    const CHALLENGE_WINDOW_SIZE_01 = '01';
+    const CHALLENGE_WINDOW_SIZE_02 = '02';
+    const CHALLENGE_WINDOW_SIZE_03 = '03';
+    const CHALLENGE_WINDOW_SIZE_04 = '04';
+    const CHALLENGE_WINDOW_SIZE_05 = '05';
+
     /**
      * @var string The service name, used in the endpoint URL.
      */
@@ -70,6 +98,17 @@ public function getTxType()
         throw new InvalidRequestException('Transaction type not defined.');
     }
 
+
+    public function getProtocol()
+    {
+        return $this->getParameter('protocol');
+    }
+
+    public function setProtocol($value)
+    {
+        return $this->setParameter('protocol', $value);
+    }
+
     /**
      * Basic authorisation, transaction type and protocol version.
      *
@@ -79,7 +118,7 @@ protected function getBaseData()
     {
         $data = array();
 
-        $data['VPSProtocol'] = $this->VPSProtocol;
+        $data['VPSProtocol'] = $this->getProtocol() ?: $this->VPSProtocol;
         $data['TxType'] = $this->getTxType();
         $data['Vendor'] = $this->getVendor();
         $data['AccountType'] = $this->getAccountType() ?: static::ACCOUNT_TYPE_E;
diff --git a/src/Message/DirectAuthorizeRequest.php b/src/Message/DirectAuthorizeRequest.php
index 19325f24..4e6179ed 100644
--- a/src/Message/DirectAuthorizeRequest.php
+++ b/src/Message/DirectAuthorizeRequest.php
@@ -56,6 +56,32 @@ protected function getBaseAuthorizeData()
         $data['VendorTxCode'] = $this->getTransactionId();
         $data['ClientIPAddress'] = $this->getClientIp();
 
+        $data['BrowserJavascriptEnabled'] = $this->getBrowserJavascriptEnabled() ?: static::BROWSER_JAVASCRIPT_NO;
+        $data['BrowserLanguage'] = $this->getBrowserLanguage() ?: static::BROWSER_LANGUAGE;
+        $data['ThreeDSNotificationURL'] = $this->getThreeDSNotificationURL();
+        $data['BrowserAcceptHeader'] = $_SERVER['HTTP_ACCEPT'];
+        $data['BrowserUserAgent'] = $_SERVER['HTTP_USER_AGENT'];
+        $data['ChallengeWindowSize'] = $this->getChallengeWindowSize() ?: static::CHALLENGE_WINDOW_SIZE_05;
+        // ----
+        // ---- "4.00" - required if BrowserJavascriptEnabled == "1"
+        $data['BrowserJavaEnabled'] = $this->getBrowserJavaEnabled();
+        $data['BrowserColorDepth'] = $this->getBrowserColorDepth();
+        $data['BrowserScreenHeight'] = $this->getBrowserScreenHeight();
+        $data['BrowserScreenWidth'] = $this->getBrowserScreenWidth();
+        $data['BrowserTZ'] = $this->getBrowserTZ();
+        // ----
+
+        // repeat payments required fields
+        $data['MITType'] = $this->getMITType();
+        $data['COFUsage'] = $this->getCOFUsage();
+        $data['InitiatedType'] = $this->getInitiatedType();
+        $data['SchemeTraceID'] = $this->getSchemeTraceID();
+        $data['RecurringExpiry'] = $this->getRecurringExpiry();
+        $data['RecurringFrequency'] = $this->getRecurringFrequency();
+        $data['ACSTransID'] = $this->getACSTransID();
+        $data['DSTransID'] = $this->getDSTransID();
+
+
         $data['ApplyAVSCV2'] = $this->getApplyAVSCV2() ?: static::APPLY_AVSCV2_DEFAULT;
         $data['Apply3DSecure'] = $this->getApply3DSecure() ?: static::APPLY_3DSECURE_APPLY;
 
diff --git a/src/Message/DirectCompleteAuthorizeRequest.php b/src/Message/DirectCompleteAuthorizeRequest.php
index 973ae88e..863475ca 100644
--- a/src/Message/DirectCompleteAuthorizeRequest.php
+++ b/src/Message/DirectCompleteAuthorizeRequest.php
@@ -16,19 +16,27 @@ public function getService()
 
     public function getData()
     {
-        // Inconsistent letter case is intentional.
-        // The issuing bank will return PaRes, but the merchant
-        // site must send this result as PARes to Sage Pay.
+        if($this->httpRequest->request->has('cres')){
+            $data = array(
+                'CRes' => $this->httpRequest->request->get('cres'), // inconsistent caps are intentional
+                'VPSTxId' => $this->httpRequest->request->get('threeDSSessionData'),
+            );
 
-        $data = array(
-            'MD' => $this->getMd() ?: $this->httpRequest->request->get('MD'),
-            'PARes' => $this->getPaRes() ?: $this->httpRequest->request->get('PaRes'),
-        );
+            if (empty($data['CRes']) || empty($data['VPSTxId'])) {
+                throw new InvalidResponseException;
+            }
+        }else{
+            $data = array(
+                'MD' => $this->httpRequest->request->get('MD'),
+                'PARes' => $this->httpRequest->request->get('PaRes'), // inconsistent caps are intentional
+            );
 
-        if (empty($data['MD']) || empty($data['PARes'])) {
-            throw new InvalidResponseException;
+            if (empty($data['MD']) || empty($data['PARes'])) {
+                throw new InvalidResponseException;
+            }
         }
 
+
         return $data;
     }
 
diff --git a/src/Message/Response.php b/src/Message/Response.php
index 34d54d34..76fefb25 100644
--- a/src/Message/Response.php
+++ b/src/Message/Response.php
@@ -96,11 +96,21 @@ public function getRedirectMethod()
     public function getRedirectData()
     {
         if ($this->isRedirect()) {
-            return array(
-                'PaReq' => $this->getDataItem('PAReq'),
-                'TermUrl' => $this->getRequest()->getReturnUrl(),
-                'MD' => $this->getDataItem('MD'),
-            );
+            if (isset($this->data['CReq'])) {
+                // 3DSv2
+                return [
+                    'creq' => $this->data['CReq'],
+                    'threeDSSessionData' => $this->data['VPSTxId'],
+                ];
+            } else {
+                // fallback from 3DSv2 to 3DSv1
+                return [
+                    'PaReq' => $this->data['PAReq'],
+                    'TermUrl' => $this->getRequest()->getReturnUrl(),
+                    'MD' => $this->data['MD'],
+                ];
+            }
+
         }
     }
 
diff --git a/src/Message/SharedRepeatAuthorizeRequest.php b/src/Message/SharedRepeatAuthorizeRequest.php
index 23331684..a65a72be 100644
--- a/src/Message/SharedRepeatAuthorizeRequest.php
+++ b/src/Message/SharedRepeatAuthorizeRequest.php
@@ -91,6 +91,19 @@ public function getData()
             $data['BasketXML'] = $basketXML;
         }
 
+        // add v4 request fields
+        if ($this->getProtocol() == '4.00'){
+
+            $data['MITType'] = $this->getMITType();
+            $data['COFUsage'] = $this->getCOFUsage();
+            $data['InitiatedType'] = $this->getInitiatedType();
+            $data['SchemeTraceID'] = $this->getSchemeTraceID();
+            $data['RecurringExpiry'] = $this->getRecurringExpiry();
+            $data['RecurringFrequency'] = $this->getRecurringFrequency();
+            $data['ACSTransID'] = $this->getACSTransID();
+            $data['DSTransID'] = $this->getDSTransID();
+        }
+
         return $data;
     }
 
diff --git a/src/Traits/GatewayParamsTrait.php b/src/Traits/GatewayParamsTrait.php
index 83ccdd26..15e56c14 100644
--- a/src/Traits/GatewayParamsTrait.php
+++ b/src/Traits/GatewayParamsTrait.php
@@ -257,4 +257,175 @@ public function setDisableUtf8Decode($value)
     {
         return $this->setParameter('disableUtf8Decode', $value);
     }
+
+    public function setThreeDSNotificationURL($value)
+    {
+        return $this->setParameter('ThreeDSNotificationURL', $value);
+    }
+
+    public function getThreeDSNotificationURL()
+    {
+        return $this->getParameter('ThreeDSNotificationURL');
+    }
+
+    public function setBrowserJavascriptEnabled($value)
+    {
+        return $this->setParameter('BrowserJavascriptEnabled', $value);
+    }
+
+    public function getBrowserJavascriptEnabled()
+    {
+        return $this->getParameter('BrowserJavascriptEnabled');
+    }
+
+    public function setBrowserLanguage($value)
+    {
+        return $this->setParameter('BrowserLanguage', $value);
+    }
+
+    public function getBrowserLanguage()
+    {
+        return $this->getParameter('BrowserLanguage');
+    }
+
+    public function setChallengeWindowSize($value)
+    {
+        return $this->setParameter('ChallengeWindowSize', $value);
+    }
+
+    public function getChallengeWindowSize()
+    {
+        return $this->getParameter('ChallengeWindowSize');
+    }
+
+    public function setBrowserJavaEnabled($value)
+    {
+        return $this->setParameter('BrowserJavaEnabled', $value);
+    }
+
+    public function getBrowserJavaEnabled()
+    {
+        return $this->getParameter('BrowserJavaEnabled');
+    }
+
+
+    public function setBrowserColorDepth($value)
+    {
+        return $this->setParameter('BrowserColorDepth', $value);
+    }
+
+    public function getBrowserColorDepth()
+    {
+        return $this->getParameter('BrowserColorDepth');
+    }
+
+    public function setBrowserScreenHeight($value)
+    {
+        return $this->setParameter('BrowserScreenHeight', $value);
+    }
+
+    public function getBrowserScreenHeight()
+    {
+        return $this->getParameter('BrowserScreenHeight');
+    }
+
+    public function setBrowserScreenWidth($value)
+    {
+        return $this->setParameter('BrowserScreenWidth', $value);
+    }
+
+    public function getBrowserScreenWidth()
+    {
+        return $this->getParameter('BrowserScreenWidth');
+    }
+
+    public function setBrowserTZ($value)
+    {
+        return $this->setParameter('BrowserTZ', $value);
+    }
+
+    public function getBrowserTZ()
+    {
+        return $this->getParameter('BrowserTZ');
+    }
+
+    public function setInitiatedType($value)
+    {
+        return $this->setParameter('InitiatedType', $value);
+    }
+
+    public function getInitiatedType()
+    {
+        return $this->getParameter('InitiatedType');
+    }
+
+    public function setCOFUsage($value)
+    {
+        return $this->setParameter('COFUsage', $value);
+    }
+
+    public function getCOFUsage()
+    {
+        return $this->getParameter('COFUsage');
+    }
+
+    public function setMITType($value)
+    {
+        return $this->setParameter('MITType', $value);
+    }
+
+    public function getMITType()
+    {
+        return $this->getParameter('MITType');
+    }
+
+    public function setSchemeTraceID($value)
+    {
+        return $this->setParameter('SchemeTraceID', $value);
+    }
+
+    public function getSchemeTraceID()
+    {
+        return $this->getParameter('SchemeTraceID');
+    }
+
+    public function setRecurringExpiry($value)
+    {
+        return $this->setParameter('RecurringExpiry', $value);
+    }
+
+    public function getRecurringExpiry()
+    {
+        return $this->getParameter('RecurringExpiry');
+    }
+
+    public function setRecurringFrequency($value)
+    {
+        return $this->setParameter('RecurringFrequency', $value);
+    }
+
+    public function getRecurringFrequency()
+    {
+        return $this->getParameter('RecurringFrequency');
+    }
+
+    public function setACSTransID($value)
+    {
+        return $this->setParameter('ACSTransID', $value);
+    }
+
+    public function getACSTransID()
+    {
+        return $this->getParameter('ACSTransID');
+    }
+
+    public function setDSTransID($value)
+    {
+        return $this->setParameter('DSTransID', $value);
+    }
+
+    public function getDSTransID()
+    {
+        return $this->getParameter('DSTransID');
+    }
 }
diff --git a/src/Traits/ServerNotifyTrait.php b/src/Traits/ServerNotifyTrait.php
index 0d54111b..defc2203 100644
--- a/src/Traits/ServerNotifyTrait.php
+++ b/src/Traits/ServerNotifyTrait.php
@@ -91,6 +91,18 @@ public function buildSignature()
                     $this->getBankAuthCode(),
                 )
             );
+            // new in v4
+            if ( $this->getDataItem('VPSProtocol') =='4.00'){
+                $signatureData = array_merge(
+                    $signatureData,
+                    array(
+                        $this->getDataItem('ACSTransID'),
+                        $this->getDataItem('DSTransID'),
+                        $this->getDataItem('SchemeTraceID'),
+                    )
+                );
+            }
+
         }
 
         return md5(implode('', $signatureData));