diff --git a/CHANGELOG.md b/CHANGELOG.md
index 06b129d..5f30030 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,7 @@
 # Changelog
+## 4.1.0
+* added `Castle\PaymentRequiredError` (`Castle_PaymentRequiredError`) for HTTP 402 responses
+
 ## 4.0.0
 **BREAKING CHANGES:**
 
diff --git a/README.md b/README.md
index 2660eec..5e34747 100644
--- a/README.md
+++ b/README.md
@@ -254,6 +254,7 @@ Whenever something unexpected happens, an [exception](lib/Castle/Errors.php) is
 | `Castle_InternalServerError`    | The Castle API returned a `5xx` response (triggers failover) |
 | `Castle_ConfigurationError`     | The Castle secret API key has not been set |
 | `Castle_UnauthorizedError`      | Wrong Castle API secret key |
+| `Castle_PaymentRequiredError`   | HTTP 402 response |
 | `Castle_BadRequest`             | The request was invalid. For example if a challenge is created without the user having MFA enabled. |
 | `Castle_ForbiddenError`         | The user has entered the wrong code too many times and a new challenge has to be requested. |
 | `Castle_NotFoundError`          | The resource requestd was not found. For example if a session has been revoked. |
diff --git a/lib/Castle/Castle.php b/lib/Castle/Castle.php
index 0e40e26..9ee624b 100755
--- a/lib/Castle/Castle.php
+++ b/lib/Castle/Castle.php
@@ -4,7 +4,7 @@
 
 abstract class Castle
 {
-  const VERSION = '4.0.0';
+  const VERSION = '4.1.0';
 
   const HEADER_COOKIE = 'Cookie';
   const HEADER_USER_AGENT = 'User-Agent';
diff --git a/lib/Castle/Errors.php b/lib/Castle/Errors.php
index 9fe5610..a0beb19 100755
--- a/lib/Castle/Errors.php
+++ b/lib/Castle/Errors.php
@@ -65,6 +65,11 @@ class InvalidRequestTokenError extends InvalidParametersError
 
 }
 
+class PaymentRequiredError extends ApiError
+{
+
+}
+
 class WebhookVerificationError extends Error
 {
 
diff --git a/lib/Castle/Request.php b/lib/Castle/Request.php
index 7821792..38f3065 100755
--- a/lib/Castle/Request.php
+++ b/lib/Castle/Request.php
@@ -23,6 +23,8 @@ public function handleApiError($response, $status)
         throw new BadRequest($msg, $type, $status);
       case 401:
         throw new UnauthorizedError($msg, $type, $status);
+      case 402:
+        throw new PaymentRequiredError($msg, $type, $status);
       case 403:
         throw new ForbiddenError($msg, $type, $status);
       case 404:
diff --git a/lib/aliases.php b/lib/aliases.php
index f15aa36..7ccd021 100644
--- a/lib/aliases.php
+++ b/lib/aliases.php
@@ -41,6 +41,7 @@ function castle_legacy_alias_map()
       'Castle_NotFoundError' => 'Castle\\NotFoundError',
       'Castle_InvalidParametersError' => 'Castle\\InvalidParametersError',
       'Castle_InvalidRequestTokenError' => 'Castle\\InvalidRequestTokenError',
+      'Castle_PaymentRequiredError' => 'Castle\\PaymentRequiredError',
       'Castle_WebhookVerificationError' => 'Castle\\WebhookVerificationError',
     );
   }
@@ -82,6 +83,7 @@ class_alias($target, $class);
     'Castle\\NotFoundError',
     'Castle\\InvalidParametersError',
     'Castle\\InvalidRequestTokenError',
+    'Castle\\PaymentRequiredError',
     'Castle\\WebhookVerificationError',
   );
 
diff --git a/test/ErrorsTest.php b/test/ErrorsTest.php
index 252fda9..fc3f626 100644
--- a/test/ErrorsTest.php
+++ b/test/ErrorsTest.php
@@ -27,6 +27,14 @@ public function testUnauthorized()
     $this->request->send('GET', '/test');
   }
 
+  public function testPaymentRequired()
+  {
+    Castle_RequestTransport::setResponse(402);
+
+    $this->expectException(Castle_PaymentRequiredError::class);
+    $this->request->send('GET', '/test');
+  }
+
   public function testForbidden()
   {
     Castle_RequestTransport::setResponse(403);
diff --git a/test/RequestContextTest.php b/test/RequestContextTest.php
index cafc740..c623146 100644
--- a/test/RequestContextTest.php
+++ b/test/RequestContextTest.php
@@ -28,7 +28,7 @@ public function contextProvider() {
   }
 
   public function contextJsonProvider() {
-    return array(array('{"ip":"8.8.8.8","headers":{"User-Agent":"TestAgent","X-Castle-Client-Id":"1ccf8dee-904b-4d20-8a88-55ded468bcc5"},"library":{"name":"castle-php","version":"4.0.0"}}'));
+    return array(array('{"ip":"8.8.8.8","headers":{"User-Agent":"TestAgent","X-Castle-Client-Id":"1ccf8dee-904b-4d20-8a88-55ded468bcc5"},"library":{"name":"castle-php","version":"4.1.0"}}'));
   }
 
   /**