diff --git a/src/Gateway.php b/src/Gateway.php
index 5044e98..50c3ef6 100644
--- a/src/Gateway.php
+++ b/src/Gateway.php
@@ -3,8 +3,12 @@
 namespace Omnipay\Netaxept;
 
 use Omnipay\Common\AbstractGateway;
+use Omnipay\Netaxept\Message\AnnulRequest;
+use Omnipay\Netaxept\Message\AuthorizeRequest;
+use Omnipay\Netaxept\Message\CompleteAuthorizeRequest;
 use Omnipay\Netaxept\Message\PurchaseRequest;
 use Omnipay\Netaxept\Message\CompletePurchaseRequest;
+use Omnipay\Netaxept\Message\CreditRequest;
 
 /**
  * Netaxept Gateway
@@ -47,28 +51,38 @@ public function setPassword($value)
         return $this->setParameter('password', $value);
     }
 
+    public function authorize($parameters = array())
+    {
+        return $this->createRequest(AuthorizeRequest::class, $parameters);
+    }
+
+    public function completeAuthorize($parameters = array())
+    {
+        return $this->createRequest(CompleteAuthorizeRequest::class, $parameters);
+    }
+
     public function purchase(array $parameters = array())
     {
-        return $this->createRequest('\Omnipay\Netaxept\Message\PurchaseRequest', $parameters);
+        return $this->createRequest(PurchaseRequest::class, $parameters);
     }
 
     public function completePurchase(array $parameters = array())
     {
-        return $this->createRequest('\Omnipay\Netaxept\Message\CompletePurchaseRequest', $parameters);
+        return $this->createRequest(CompletePurchaseRequest::class, $parameters);
     }
 
     public function capture(array $parameters = array())
     {
-        return $this->createRequest('\Omnipay\Netaxept\Message\CaptureRequest', $parameters);
+        return $this->createRequest(CaptureRequest::class, $parameters);
     }
 
     public function void(array $parameters = array())
     {
-        return $this->createRequest('\Omnipay\Netaxept\Message\AnnulRequest', $parameters);
+        return $this->createRequest(AnnulRequest::class, $parameters);
     }
 
     public function credit(array $parameters = array())
     {
-        return $this->createRequest('\Omnipay\Netaxept\Message\CreditRequest', $parameters);
+        return $this->createRequest(CreditRequest::class, $parameters);
     }
 }
diff --git a/src/Message/AuthorizeRequest.php b/src/Message/AuthorizeRequest.php
new file mode 100644
index 0000000..232082e
--- /dev/null
+++ b/src/Message/AuthorizeRequest.php
@@ -0,0 +1,98 @@
+<?php
+
+namespace Omnipay\Netaxept\Message;
+
+use Omnipay\Common\Message\AbstractRequest;
+
+/**
+ * Netaxept Authorize Request
+ */
+class AuthorizeRequest extends AbstractRequest
+{
+    protected $liveEndpoint = 'https://epayment.nets.eu';
+    protected $testEndpoint = 'https://test.epayment.nets.eu';
+
+    public function getMerchantId()
+    {
+        return $this->getParameter('merchantId');
+    }
+
+    public function setMerchantId($value)
+    {
+        return $this->setParameter('merchantId', $value);
+    }
+
+    public function getPassword()
+    {
+        return $this->getParameter('password');
+    }
+
+    public function setPassword($value)
+    {
+        return $this->setParameter('password', $value);
+    }
+
+    public function getLanguage()
+    {
+        return $this->getParameter('language');
+    }
+
+    public function setLanguage($value)
+    {
+        return $this->setParameter('language', $value);
+    }
+
+    public function setPaymentMethodActionList($value)
+    {
+        return $this->setParameter('paymentMethodActionList', $value);
+    }
+
+    public function getPaymentMethodActionList()
+    {
+        return $this->getParameter('paymentMethodActionList');
+    }
+
+    public function getData()
+    {
+        $this->validate('amount', 'currency', 'transactionId', 'returnUrl');
+
+        $data = array();
+        $data['merchantId'] = $this->getMerchantId();
+        $data['token'] = $this->getPassword();
+        $data['serviceType'] = 'B';
+        $data['orderNumber'] = $this->getTransactionId();
+        $data['transactionId'] = $this->getTransactionReference();
+        $data['currencyCode'] = $this->getCurrency();
+        $data['amount'] = $this->getAmountInteger();
+        $data['redirectUrl'] = $this->getReturnUrl();
+        $data['language'] = $this->getLanguage();
+        $data['paymentMethodActionList'] = $this->getPaymentMethodActionList();
+
+        if ($this->getCard()) {
+            $data['customerFirstName'] = $this->getCard()->getFirstName();
+            $data['customerLastName'] = $this->getCard()->getLastName();
+            $data['customerEmail'] = $this->getCard()->getEmail();
+            $data['customerPhoneNumber'] = $this->getCard()->getPhone();
+            $data['customerAddress1'] = $this->getCard()->getAddress1();
+            $data['customerAddress2'] = $this->getCard()->getAddress2();
+            $data['customerPostcode'] = $this->getCard()->getPostcode();
+            $data['customerTown'] = $this->getCard()->getCity();
+            $data['customerCountry'] = $this->getCard()->getCountry();
+        }
+
+        return $data;
+    }
+
+    public function sendData($data)
+    {
+        $url = $this->getEndpoint().'/Netaxept/Register.aspx?';
+        $httpResponse = $this->httpClient->request('GET', $url.http_build_query($data));
+
+        return $this->response = new Response($this, simplexml_load_string($httpResponse->getBody()->getContents()));
+    }
+
+    public function getEndpoint()
+    {
+        return $this->getTestMode() ? $this->testEndpoint : $this->liveEndpoint;
+    }
+}
diff --git a/src/Message/CaptureRequest.php b/src/Message/CaptureRequest.php
index fe88400..470d6cc 100644
--- a/src/Message/CaptureRequest.php
+++ b/src/Message/CaptureRequest.php
@@ -15,13 +15,13 @@ public function getData()
     {
         $data = array();
         $data['transactionAmount'] = $this->getAmountInteger();
-        $data['transactionId'] = $this->getTransactionId();
+        $data['transactionId'] = $this->getTransactionReference();
         $data['merchantId'] = $this->getMerchantId();
         $data['token'] = $this->getPassword();
         $data['operation'] = 'CAPTURE';
 
         if (empty($data['transactionAmount']) || empty($data['transactionId'])) {
-            throw new InvalidResponseException;
+            throw new InvalidResponseException();
         }
 
         return $data;
diff --git a/src/Message/CompleteAuthorizeRequest.php b/src/Message/CompleteAuthorizeRequest.php
new file mode 100644
index 0000000..5d80991
--- /dev/null
+++ b/src/Message/CompleteAuthorizeRequest.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Omnipay\Netaxept\Message;
+
+use Omnipay\Common\Exception\InvalidResponseException;
+
+/**
+ * Netaxept Complete Purchase Request
+ */
+class CompleteAuthorizeRequest extends PurchaseRequest
+{
+    public function getData()
+    {
+        $data = array();
+        $data['responseCode'] = $this->httpRequest->query->get('responseCode');
+        $data['transactionId'] = $this->httpRequest->query->get('transactionId');
+        $data['merchantId'] = $this->getMerchantId();
+        $data['token'] = $this->getPassword();
+        $data['operation'] = 'AUTH';
+
+        if (empty($data['responseCode']) || empty($data['transactionId'])) {
+            throw new InvalidResponseException();
+        }
+
+        return $data;
+    }
+
+    public function sendData($data)
+    {
+        if ('OK' !== $data['responseCode']) {
+            return $this->response = new ErrorResponse($this, $data);
+        }
+
+        $url = $this->getEndpoint().'/Netaxept/Process.aspx?';
+        $httpResponse = $this->httpClient->request('GET', $url.http_build_query($data));
+
+        return $this->response = new Response($this, simplexml_load_string($httpResponse->getBody()->getContents()));
+    }
+}
diff --git a/src/Message/PurchaseRequest.php b/src/Message/PurchaseRequest.php
index 0419912..55913fa 100644
--- a/src/Message/PurchaseRequest.php
+++ b/src/Message/PurchaseRequest.php
@@ -42,6 +42,16 @@ public function setLanguage($value)
         return $this->setParameter('language', $value);
     }
 
+    public function setPaymentMethodActionList($value)
+    {
+        return $this->setParameter('paymentMethodActionList', $value);
+    }
+
+    public function getPaymentMethodActionList()
+    {
+        return $this->getParameter('paymentMethodActionList');
+    }
+
     public function getData()
     {
         $this->validate('amount', 'currency', 'transactionId', 'returnUrl');
@@ -51,10 +61,12 @@ public function getData()
         $data['token'] = $this->getPassword();
         $data['serviceType'] = 'B';
         $data['orderNumber'] = $this->getTransactionId();
+        $data['transactionId'] = $this->getTransactionReference();
         $data['currencyCode'] = $this->getCurrency();
         $data['amount'] = $this->getAmountInteger();
         $data['redirectUrl'] = $this->getReturnUrl();
         $data['language'] = $this->getLanguage();
+        $data['paymentMethodActionList'] = $this->getPaymentMethodActionList();
 
         if ($this->getCard()) {
             $data['customerFirstName'] = $this->getCard()->getFirstName();
diff --git a/tests/GatewayTest.php b/tests/GatewayTest.php
index 7cfa850..fe3f07e 100644
--- a/tests/GatewayTest.php
+++ b/tests/GatewayTest.php
@@ -103,6 +103,87 @@ public function testCompletePurchaseFailure()
         $this->assertSame('Unable to find transaction', $response->getMessage());
     }
 
+    public function testAuthorizeSuccess()
+    {
+        $this->setMockHttpResponse('AuthorizeSuccess.txt');
+
+        $response = $this->gateway->authorize($this->options)->send();
+
+        $this->assertFalse($response->isSuccessful());
+        $this->assertTrue($response->isRedirect());
+        $this->assertEquals('f3d94dd5c0f743a788fc943402757c58', $response->getTransactionReference());
+        $this->assertSame('GET', $response->getRedirectMethod());
+        $this->assertSame('https://epayment.nets.eu/Terminal/Default.aspx?merchantId=foo&transactionId=f3d94dd5c0f743a788fc943402757c58', $response->getRedirectUrl());
+    }
+
+    public function testAuthorizeFailure()
+    {
+        $this->setMockHttpResponse('AuthorizeFailure.txt');
+
+        $response = $this->gateway->authorize($this->options)->send();
+
+        $this->assertFalse($response->isSuccessful());
+        $this->assertFalse($response->isRedirect());
+        $this->assertNull($response->getTransactionReference());
+        $this->assertSame("Missing parameter: 'Order Number'", $response->getMessage());
+    }
+
+    public function testCompleteAuthorizeSuccess()
+    {
+        $this->getHttpRequest()->query->replace(
+            array(
+                'responseCode' => 'OK',
+                'transactionId' => 'abc123',
+            )
+        );
+
+        $this->setMockHttpResponse('CompleteAuthorizeSuccess.txt');
+
+        $response = $this->gateway->completeAuthorize($this->options)->send();
+
+        $this->assertTrue($response->isSuccessful());
+        $this->assertFalse($response->isRedirect());
+        $this->assertEquals('8a88d40cab5b47fab25e24d6228180a7', $response->getTransactionReference());
+        $this->assertSame('OK', $response->getMessage());
+    }
+
+    public function testCompleteAuthorizeCancel()
+    {
+        $this->getHttpRequest()->query->replace(
+            array(
+                'transactionId' => '1de59458487344759832716abf48109b',
+                'responseCode' => 'Cancel',
+            )
+        );
+
+        $response = $this->gateway->completeAuthorize($this->options)->send();
+
+        $this->assertFalse($response->isSuccessful());
+        $this->assertFalse($response->isRedirect());
+        $this->assertEquals('1de59458487344759832716abf48109b', $response->getTransactionReference());
+        $this->assertEquals('Cancel', $response->getMessage());
+    }
+
+    public function testCompleteAuthorizeFailure()
+    {
+        $this->getHttpRequest()->query->replace(
+            array(
+                'responseCode' => 'OK',
+                'transactionId' => 'abc123',
+            )
+        );
+
+        $this->setMockHttpResponse('CompleteAuthorizeFailure.txt');
+
+        $response = $this->gateway->completeAuthorize($this->options)->send();
+
+        $this->assertFalse($response->isSuccessful());
+        $this->assertFalse($response->isRedirect());
+        $this->assertNull($response->getTransactionReference());
+
+        $this->assertSame('Unable to find transaction', $response->getMessage());
+    }
+
     public function testCaptureSuccess()
     {
         $this->setMockHttpResponse('CaptureSuccess.txt');
diff --git a/tests/Message/AuthorizeRequestTest.php b/tests/Message/AuthorizeRequestTest.php
new file mode 100644
index 0000000..548f043
--- /dev/null
+++ b/tests/Message/AuthorizeRequestTest.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace Omnipay\Netaxept\Message;
+
+use Omnipay\Common\CreditCard;
+use Omnipay\Tests\TestCase;
+
+class AuthorizeRequestTest extends TestCase
+{
+    /**
+     * @var \Omnipay\Netaxept\Message\AuthorizeRequest
+     */
+    private $request;
+
+    public function setUp()
+    {
+        $client = $this->getHttpClient();
+        $request = $this->getHttpRequest();
+
+        $this->request = new AuthorizeRequest($client, $request);
+    }
+
+    public function testGetDataWithCard()
+    {
+        $this->request->setMerchantId('MERCH-123');
+        $this->request->setPassword('PASSWORD-123');
+        $this->request->setAmount('1.23');
+        $this->request->setCurrency('USD');
+        $this->request->setTransactionId('ABC-123');
+        $this->request->setReturnUrl('http://return.domain.com/');
+        $this->request->setLanguage('en_GB');
+
+        $card = new CreditCard(array(
+            'firstName' => 'John',
+            'lastName' => 'Doe',
+            'email' => 'test@email.com',
+            'phone' => '555-555-5555',
+            'address1' => '123 NW Blvd',
+            'address2' => 'Lynx Lane',
+            'postcode' => '66605',
+            'city' => 'Topeka',
+            'country' => 'USA',
+        ));
+        $this->request->setCard($card);
+
+        $expected = array(
+            'merchantId' => 'MERCH-123',
+            'token' => 'PASSWORD-123',
+            'serviceType' => 'B',
+            'orderNumber' => 'ABC-123',
+            'currencyCode' => 'USD',
+            'amount' => 123,
+            'redirectUrl' => 'http://return.domain.com/',
+            'language' => 'en_GB',
+            'customerFirstName' => 'John',
+            'customerLastName' => 'Doe',
+            'customerEmail' => 'test@email.com',
+            'customerPhoneNumber' => '555-555-5555',
+            'customerAddress1' => '123 NW Blvd',
+            'customerAddress2' => 'Lynx Lane',
+            'customerPostcode' => '66605',
+            'customerTown' => 'Topeka',
+            'customerCountry' => 'USA',
+        );
+
+        $this->assertEquals($expected, $this->request->getData());
+    }
+}
diff --git a/tests/Message/CompleteAuthorizeRequestTest.php b/tests/Message/CompleteAuthorizeRequestTest.php
new file mode 100644
index 0000000..04a355d
--- /dev/null
+++ b/tests/Message/CompleteAuthorizeRequestTest.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace Omnipay\Netaxept\Message;
+
+use Omnipay\Tests\TestCase;
+
+class CompleteAuthorizeRequestTest extends TestCase
+{
+    /**
+     * @var \Symfony\Component\HttpFoundation\Request
+     */
+    private $httpRequest;
+
+    /**
+     * @var \Omnipay\Netaxept\Message\CompleteAuthorizeRequest
+     */
+    private $request;
+
+    public function setUp()
+    {
+        $client = $this->getHttpClient();
+        $this->httpRequest = $this->getHttpRequest();
+
+        $this->request = new CompleteAuthorizeRequest($client, $this->httpRequest);
+    }
+
+    /**
+     * @expectedException \Omnipay\Common\Exception\InvalidResponseException
+     */
+    public function testGetDataThrowsExceptionWithoutResponseCode()
+    {
+        $this->httpRequest->query->set('transactionId', 'TRANS-123');
+
+        $this->request->getData();
+    }
+
+    /**
+     * @expectedException \Omnipay\Common\Exception\InvalidResponseException
+     */
+    public function testGetDataThrowsExceptionWithoutTransactionId()
+    {
+        $this->httpRequest->query->set('responseCode', 'ABC-123');
+
+        $this->request->getData();
+    }
+}
diff --git a/tests/Mock/AuthorizeFailure.txt b/tests/Mock/AuthorizeFailure.txt
new file mode 100644
index 0000000..6ed37ee
--- /dev/null
+++ b/tests/Mock/AuthorizeFailure.txt
@@ -0,0 +1,15 @@
+HTTP/1.1 200 OK
+Cache-Control: private
+Content-Type: text/xml
+Server: Microsoft-IIS/7.5
+X-AspNet-Version: 4.0.30319
+X-Powered-By: ASP.NET
+Date: Fri, 22 Feb 2013 15:53:42 GMT
+Content-Length: 259
+
+<?xml version="1.0"?>
+<Exception xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
+  <Error xsi:type="ValidationException">
+    <Message>Missing parameter: 'Order Number'</Message>
+  </Error>
+</Exception>
diff --git a/tests/Mock/AuthorizeSuccess.txt b/tests/Mock/AuthorizeSuccess.txt
new file mode 100644
index 0000000..966cbe4
--- /dev/null
+++ b/tests/Mock/AuthorizeSuccess.txt
@@ -0,0 +1,13 @@
+HTTP/1.1 200 OK
+Cache-Control: private
+Content-Type: text/xml
+Server: Microsoft-IIS/7.5
+X-AspNet-Version: 4.0.30319
+X-Powered-By: ASP.NET
+Date: Fri, 22 Feb 2013 15:55:07 GMT
+Content-Length: 228
+
+<?xml version="1.0"?>
+<RegisterResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
+  <TransactionId>f3d94dd5c0f743a788fc943402757c58</TransactionId>
+</RegisterResponse>
diff --git a/tests/Mock/CompleteAuthorizeFailure.txt b/tests/Mock/CompleteAuthorizeFailure.txt
new file mode 100644
index 0000000..f9481fb
--- /dev/null
+++ b/tests/Mock/CompleteAuthorizeFailure.txt
@@ -0,0 +1,15 @@
+HTTP/1.1 200 OK
+Cache-Control: private
+Content-Type: text/xml
+Server: Microsoft-IIS/7.5
+X-AspNet-Version: 4.0.30319
+X-Powered-By: ASP.NET
+Date: Fri, 22 Feb 2013 16:55:41 GMT
+Content-Length: 245
+
+<?xml version="1.0"?>
+<Exception xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
+  <Error xsi:type="GenericError">
+    <Message>Unable to find transaction</Message>
+  </Error>
+</Exception>
diff --git a/tests/Mock/CompleteAuthorizeSuccess.txt b/tests/Mock/CompleteAuthorizeSuccess.txt
new file mode 100644
index 0000000..062ae13
--- /dev/null
+++ b/tests/Mock/CompleteAuthorizeSuccess.txt
@@ -0,0 +1,19 @@
+HTTP/1.1 200 OK
+Cache-Control: private
+Content-Type: text/xml
+Server: Microsoft-IIS/7.5
+X-AspNet-Version: 4.0.30319
+X-Powered-By: ASP.NET
+Date: Fri, 22 Feb 2013 16:53:34 GMT
+Content-Length: 474
+
+<?xml version="1.0"?>
+<ProcessResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
+  <Operation>AUTH</Operation>
+  <ResponseCode>OK</ResponseCode>
+  <AuthorizationId>090896</AuthorizationId>
+  <TransactionId>8a88d40cab5b47fab25e24d6228180a7</TransactionId>
+  <ExecutionTime>2013-02-22T17:53:33.9906245+01:00</ExecutionTime>
+  <MerchantId>424278</MerchantId>
+  <BatchNumber>246</BatchNumber>
+</ProcessResponse>