diff --git a/composer.json b/composer.json
index f5d1146..653ad69 100644
--- a/composer.json
+++ b/composer.json
@@ -20,12 +20,12 @@
         }
     ],
     "autoload": {
-        "psr-0": { "Omnipay\\Realex\\" : "src/" }
+        "psr-4": { "Omnipay\\Realex\\" : "src/" }
     },
     "require": {
-        "omnipay/common": "~2.0"
+        "omnipay/common": "^3"
     },
     "require-dev": {
-        "squizlabs/php_codesniffer": "~1.4.4"
+        "squizlabs/php_codesniffer": "^3"
     }
 }
diff --git a/src/Omnipay/Realex/Message/AuthRequest.php b/src/Omnipay/Realex/Message/AuthRequest.php
index 5e224f8..f2ced4d 100644
--- a/src/Omnipay/Realex/Message/AuthRequest.php
+++ b/src/Omnipay/Realex/Message/AuthRequest.php
@@ -12,31 +12,16 @@ class AuthRequest extends RemoteAbstractRequest
 {
     protected $endpoint = 'https://epage.payandshop.com/epage-remote.cgi';
 
-    public function getCavv()
-    {
-        return $this->getParameter('cavv');
-    }
-
     public function setCavv($value)
     {
         return $this->setParameter('cavv', $value);
     }
 
-    public function getEci()
-    {
-        return $this->getParameter('eci');
-    }
-
     public function setEci($value)
     {
         return $this->setParameter('eci', $value);
     }
 
-    public function getXid()
-    {
-        return $this->getParameter('xid');
-    }
-
     public function setXid($value)
     {
         return $this->setParameter('xid', $value);
@@ -52,17 +37,18 @@ public function getData()
         $this->validate('amount', 'currency', 'transactionId');
 
         // Create the hash
-        $timestamp = strftime("%Y%m%d%H%M%S");
+        $timestamp  = strftime("%Y%m%d%H%M%S");
         $merchantId = $this->getMerchantId();
-        $orderId = $this->getTransactionId();
-        $amount = $this->getAmountInteger();
-        $currency = $this->getCurrency();
+        $orderId    = $this->getTransactionId();
+        $amount     = $this->getAmountInteger();
+        $currency   = $this->getCurrency();
         $cardNumber = $this->getCard()->getNumber();
-        $secret = $this->getSecret();
-        $tmp = "$timestamp.$merchantId.$orderId.$amount.$currency.$cardNumber";
-        $sha1hash = sha1($tmp);
-        $tmp2 = "$sha1hash.$secret";
-        $sha1hash = sha1($tmp2);
+        $secret     = $this->getSecret();
+        $tmp        = "$timestamp.$merchantId.$orderId.$amount.$currency.$cardNumber";
+        $sha1hash   = sha1($tmp);
+        $tmp2       = "$sha1hash.$secret";
+        $sha1hash   = sha1($tmp2);
+
 
         $domTree = new \DOMDocument('1.0', 'UTF-8');
 
@@ -93,6 +79,7 @@ public function getData()
          * @var \Omnipay\Common\CreditCard $card
          */
         $card = $this->getCard();
+        $this->setCode($card->getBillingPostcode(), $card->getBillingAddress1());
 
         // Card details
         $cardEl = $domTree->createElement('card');
@@ -129,10 +116,10 @@ public function getData()
         $root->appendChild($settleEl);
 
         // 3D Secure section
-        $mpiEl = $domTree->createElement('mpi');
+        $mpiEl  = $domTree->createElement('mpi');
         $cavvEl = $domTree->createElement('cavv', $this->getCavv());
-        $xidEl = $domTree->createElement('xid', $this->getXid());
-        $eciEl = $domTree->createElement('eci', $this->getEci());
+        $xidEl  = $domTree->createElement('xid', $this->getXid());
+        $eciEl  = $domTree->createElement('eci', $this->getEci());
         $mpiEl->appendChild($cavvEl);
         $mpiEl->appendChild($xidEl);
         $mpiEl->appendChild($eciEl);
@@ -141,11 +128,13 @@ public function getData()
         $sha1El = $domTree->createElement('sha1hash', $sha1hash);
         $root->appendChild($sha1El);
 
-        $tssEl = $domTree->createElement('tssinfo');
+        $tssEl     = $domTree->createElement('tssinfo');
         $addressEl = $domTree->createElement('address');
         $addressEl->setAttribute('type', 'billing');
-        $countryEl = $domTree->createElement('country', $card->getBillingCountry());
+        $countryEl  = $domTree->createElement('country', $card->getBillingCountry());
+        $postcodeEl = $domTree->createElement('code', $this->getCode());
         $addressEl->appendChild($countryEl);
+        $addressEl->appendChild($postcodeEl);
         $tssEl->appendChild($addressEl);
         $root->appendChild($tssEl);
 
@@ -154,13 +143,28 @@ public function getData()
         return $xmlString;
     }
 
-    protected function createResponse($data)
+    public function getCavv()
     {
-        return $this->response = new AuthResponse($this, $data);
+        return $this->getParameter('cavv');
+    }
+
+    public function getXid()
+    {
+        return $this->getParameter('xid');
+    }
+
+    public function getEci()
+    {
+        return $this->getParameter('eci');
     }
 
     public function getEndpoint()
     {
         return $this->endpoint;
     }
+
+    protected function createResponse($data)
+    {
+        return $this->response = new AuthResponse($this, $data);
+    }
 }
diff --git a/src/Omnipay/Realex/Message/RemoteAbstractRequest.php b/src/Omnipay/Realex/Message/RemoteAbstractRequest.php
index 22f302a..30070ef 100644
--- a/src/Omnipay/Realex/Message/RemoteAbstractRequest.php
+++ b/src/Omnipay/Realex/Message/RemoteAbstractRequest.php
@@ -11,24 +11,26 @@
 abstract class RemoteAbstractRequest extends AbstractRequest
 {
     protected $cardBrandMap = array(
-        'mastercard' => 'mc',
-        'diners_club' => 'diners'
+        'mastercard'  => 'mc',
+        'diners_club' => 'diners',
     );
 
-    /**
-     * Override some of the default Omnipay card brand names
-     *
-     * @return mixed
-     */
-    protected function getCardBrand()
+    public function getCode()
     {
-        $brand = $this->getCard()->getBrand();
+        return $this->getParameter('code');
+    }
 
-        if (isset($this->cardBrandMap[$brand])) {
-            $brand = $this->cardBrandMap[$brand];
-        }
+    public function setCode($postcode, $billingAddressLine1)
+    {
+        $postcode            = $this->stripNonNumeric($postcode);
+        $billingAddressLine1 = $this->stripNonNumeric($billingAddressLine1);
 
-        return strtoupper($brand);
+        return $this->setParameter('code', $postcode . '|' . $billingAddressLine1);
+    }
+
+    public function stripNonNumeric($value)
+    {
+        return preg_replace("/[^0-9]/", "", $value);
     }
 
     public function getMerchantId()
@@ -74,20 +76,39 @@ public function setReturnUrl($value)
     public function sendData($data)
     {
         // register the payment
-        $this->httpClient->setConfig(
-            array(
-                'curl.options' => array(
-                    'CURLOPT_SSLVERSION'     => 1,
-                    'CURLOPT_SSL_VERIFYPEER' => false
-                )
-            )
+        $headers = array(
+            'curl' => array(
+                CURLOPT_SSLVERSION     => 1,
+                CURLOPT_SSL_VERIFYPEER => false,
+            ),
         );
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), null, $data)->send();
 
-        return $this->createResponse($httpResponse->getBody(true));
+        if (is_array($data)) {
+            $data = http_build_query($data);
+        }
+
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), $headers, $data);
+
+        return $this->createResponse($httpResponse->getBody()->getContents());
     }
 
     abstract public function getEndpoint();
 
     abstract protected function createResponse($data);
+
+    /**
+     * Override some of the default Omnipay card brand names
+     *
+     * @return mixed
+     */
+    protected function getCardBrand()
+    {
+        $brand = $this->getCard()->getBrand();
+
+        if (isset($this->cardBrandMap[ $brand ])) {
+            $brand = $this->cardBrandMap[ $brand ];
+        }
+
+        return strtoupper($brand);
+    }
 }