diff --git a/CHANGELOG.md b/CHANGELOG.md
index 76e4f8b..4252824 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 9.3.0
+
+- Add `Castle::PaymentRequiredError` for HTTP 402 responses.
+
 ## 9.2.0
 
 **Changes:**
diff --git a/Gemfile.lock b/Gemfile.lock
index 559224c..529a5c0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    castle-rb (9.2.0)
+    castle-rb (9.3.0)
       base64 (~> 0.2)
 
 GEM
diff --git a/README.md b/README.md
index 7856934..6aa4e6f 100644
--- a/README.md
+++ b/README.md
@@ -293,6 +293,7 @@ All exceptions inherit from `Castle::Error`. The most useful ones:
 | `Castle::InvalidRequestTokenError` | The `request_token` is missing or invalid.                    |
 | `Castle::InvalidParametersError`   | 422 response with validation details.                         |
 | `Castle::RateLimitError`           | 429 response — back off and retry.                            |
+| `Castle::PaymentRequiredError`     | 402 response.                                                 |
 | `Castle::UnauthorizedError`        | 401 — bad API secret.                                         |
 | `Castle::InternalServerError`      | 5xx response from Castle.                                     |
 | `Castle::WebhookVerificationError` | Webhook signature did not match.                              |
diff --git a/lib/castle/core/process_response.rb b/lib/castle/core/process_response.rb
index 9797266..8788927 100644
--- a/lib/castle/core/process_response.rb
+++ b/lib/castle/core/process_response.rb
@@ -7,6 +7,7 @@ module ProcessResponse
       RESPONSE_ERRORS = {
         400 => Castle::BadRequestError,
         401 => Castle::UnauthorizedError,
+        402 => Castle::PaymentRequiredError,
         403 => Castle::ForbiddenError,
         404 => Castle::NotFoundError,
         419 => Castle::UserUnauthorizedError,
diff --git a/lib/castle/errors.rb b/lib/castle/errors.rb
index 7530aeb..589eb35 100644
--- a/lib/castle/errors.rb
+++ b/lib/castle/errors.rb
@@ -65,6 +65,9 @@ class UnauthorizedError < Castle::ApiError
   class RateLimitError < Castle::ApiError
   end
 
+  class PaymentRequiredError < Castle::ApiError
+  end
+
   # all internal server errors
   class InternalServerError < Castle::ApiError
   end
diff --git a/lib/castle/version.rb b/lib/castle/version.rb
index c4adb7b..88daa75 100644
--- a/lib/castle/version.rb
+++ b/lib/castle/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Castle
-  VERSION = '9.2.0'
+  VERSION = '9.3.0'
 end
diff --git a/spec/lib/castle/core/process_response_spec.rb b/spec/lib/castle/core/process_response_spec.rb
index f52053d..f64a2e4 100644
--- a/spec/lib/castle/core/process_response_spec.rb
+++ b/spec/lib/castle/core/process_response_spec.rb
@@ -92,6 +92,7 @@
 
     it_behaves_like 'response_failed', '400', Castle::BadRequestError
     it_behaves_like 'response_failed', '401', Castle::UnauthorizedError
+    it_behaves_like 'response_failed', '402', Castle::PaymentRequiredError
     it_behaves_like 'response_failed', '403', Castle::ForbiddenError
     it_behaves_like 'response_failed', '404', Castle::NotFoundError
     it_behaves_like 'response_failed', '419', Castle::UserUnauthorizedError