diff --git a/src/Service/PostcodeApiClient.php b/src/Service/PostcodeApiClient.php
index 6a2785a..4e2f9b9 100644
--- a/src/Service/PostcodeApiClient.php
+++ b/src/Service/PostcodeApiClient.php
@@ -3,6 +3,7 @@
 namespace Hurnell\PostcodeApiBundle\Service;
 
 use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Exception\ClientException;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\Exception\GuzzleException;
 use Hurnell\PostcodeApiBundle\Exception\InvalidHouseNumberException;
@@ -107,6 +108,12 @@ public function makeRequest(string $postcode, $number, string $extra): self
             } catch (InvalidJsonException $exception) {
                 throw new InvalidApiResponseException('The API response could not be parsed');
             }
+        } catch (ClientException $e) {
+            $message = 'The API request failed';
+            if (429 === $e->getResponse()->getStatusCode()) {
+                $message = 'The API request failed due to too many requests';
+            }
+            throw new InvalidApiResponseException($message);
         } catch (GuzzleException $e) {
             throw new InvalidApiResponseException('The Guzzle client failed');
         }
diff --git a/tests/Service/PostcodeApiClientTest.php b/tests/Service/PostcodeApiClientTest.php
index 7fcec4b..86691a8 100644
--- a/tests/Service/PostcodeApiClientTest.php
+++ b/tests/Service/PostcodeApiClientTest.php
@@ -300,6 +300,30 @@ public function invalidExtraButValidWhenWithoutExtraProvider(): array
         ];
     }
 
+    public function testPostcodeApiTooManyRequests():void
+    {
+        $this->guzzleExpectsApiException(429);
+        $this->expectException(InvalidApiResponseException::class);
+        $this->expectExceptionMessage('The API request failed due to too many requests');
+        $this->postcodeApiClient
+            ->makeRequest(
+                '2013AH',
+                34,
+                ''
+            );
+    }
+    public function testPostcodeApiTooStatusCodeNotFound():void
+    {
+        $this->guzzleExpectsApiException(404);
+        $this->expectException(InvalidApiResponseException::class);
+        $this->expectExceptionMessage('The API request failed');
+        $this->postcodeApiClient
+            ->makeRequest(
+                '2013AH',
+                34,
+                ''
+            );
+    }
 
     /**
      * Finally check that a valid request does not throw an error and
diff --git a/tests/Service/PostcodeApiClientTestMock.php b/tests/Service/PostcodeApiClientTestMock.php
index b42a88d..c167764 100644
--- a/tests/Service/PostcodeApiClientTestMock.php
+++ b/tests/Service/PostcodeApiClientTestMock.php
@@ -2,7 +2,9 @@
 
 namespace Hurnell\PostcodeApiBundle\Tests\Service;
 
+use GuzzleHttp\Exception\ClientException;
 use GuzzleHttp\Exception\ConnectException;
+use GuzzleHttp\Psr7\Response;
 use Psr\Http\Message\RequestInterface;
 use PHPUnit\Framework\TestCase;
 use GuzzleHttp\ClientInterface;
@@ -28,6 +30,7 @@ class PostcodeApiClientTestMock extends TestCase
 
     private $guzzleException;
 
+
     public function setUp(): void
     {
         $this->guzzleClient = $this->mockGuzzleClientInterface();
@@ -35,6 +38,7 @@ public function setUp(): void
         $this->response = $this->mockResponseInterface();
         $this->stream = $this->mockStreamInterface();
         $this->guzzleException = $this->mockGuzzleException();
+
     }
 
     /**
@@ -64,6 +68,11 @@ private function mockGuzzleException(): ConnectException
     {
         return new ConnectException('this is a guzzle exception', $this->request);
     }
+    private function mockGuzzleApiException($statusCode): ClientException
+    {
+        $response = new Response($statusCode);
+        return new ClientException('this is a guzzle exception', $this->request, $response);
+    }
 
 
     protected function guzzleExpectsResponse(): void
@@ -79,6 +88,12 @@ protected function guzzleExpectsException(): void
             ->method('send')
             ->willThrowException($this->guzzleException);
     }
+    protected function guzzleExpectsApiException($statusCode): void
+    {
+        $this->guzzleClient->expects($this->once())
+            ->method('send')
+            ->willThrowException($this->mockGuzzleApiException($statusCode));
+    }
 
     /**
      * @param int $statusCode