diff --git a/src/v4/Exception/BringApiException.php b/src/v4/Exception/BringApiException.php
index 24f9623..07a5813 100644
--- a/src/v4/Exception/BringApiException.php
+++ b/src/v4/Exception/BringApiException.php
@@ -102,9 +102,60 @@ public static function fromResponse(ResponseInterface $response, ?\Throwable $pr
         }
 
         if ($errors === []) {
-            $errors[] = new BringApiError('', sprintf('HTTP %d (no parsable error body)', $status), null);
+            // No recognised error envelope. Surface a snippet of the raw body
+            // so the actual Bring rejection reason isn't lost — without this,
+            // unfamiliar 4xx shapes (plain text, HTML, JSON envelopes other
+            // than errors/messages) collapse to "no parsable error body" and
+            // the operator has nothing to act on. The body is redacted and
+            // truncated; the parseable-envelope path is unchanged so the
+            // "Bring sometimes echoes credentials" guarantee on getMessage()
+            // still holds for the case it was written for.
+            $snippet = self::redactBodySnippet($body);
+            $errors[] = new BringApiError(
+                '',
+                $snippet === ''
+                    ? sprintf('HTTP %d (empty error body)', $status)
+                    : sprintf('HTTP %d: %s', $status, $snippet),
+                null,
+            );
         }
 
         return new self($status, $errors, $response, $previous);
     }
+
+    /**
+     * Trim, single-line, truncate and redact obvious credential-shaped values
+     * from a response body so it's safe to embed in an exception message.
+     */
+    private static function redactBodySnippet(string $body): string
+    {
+        $body = trim($body);
+        if ($body === '') {
+            return '';
+        }
+
+        // Collapse whitespace so multi-line HTML/JSON doesn't blow up logs.
+        $body = (string) preg_replace('/\s+/u', ' ', $body);
+
+        // Redact common credential shapes: JSON "key":"value", form key=value,
+        // and Authorization-style header values. Match key names case-insensitively.
+        $sensitive = '(?:api[_-]?key|apikey|x-mybring-api-key|authorization|password|secret|token)';
+        $body = (string) preg_replace(
+            '/"(' . $sensitive . ')"\s*:\s*"[^"]*"/i',
+            '"$1":"[REDACTED]"',
+            $body,
+        );
+        $body = (string) preg_replace(
+            '/\b(' . $sensitive . ')\s*=\s*[^&\s"\']+/i',
+            '$1=[REDACTED]',
+            $body,
+        );
+
+        $limit = 500;
+        if (mb_strlen($body) > $limit) {
+            $body = mb_substr($body, 0, $limit) . '…';
+        }
+
+        return $body;
+    }
 }
diff --git a/tests/v4/Http/TransportTest.php b/tests/v4/Http/TransportTest.php
index 4173b5d..e52af47 100644
--- a/tests/v4/Http/TransportTest.php
+++ b/tests/v4/Http/TransportTest.php
@@ -101,6 +101,45 @@ public function testApiExceptionMessageEmbedsFirstErrorButNotRawBody(): void
         }
     }
 
+    public function testUnparsableErrorBodyIsSurfacedInMessage(): void
+    {
+        // Bring occasionally returns a 4xx with a body that doesn't fit the
+        // errors/messages envelope (plain text, HTML, a different JSON shape).
+        // We must still surface enough of it that the operator can act on it
+        // instead of collapsing to "no parsable error body".
+        $body = 'Recipient postal code 1642 is not serviced by BUSINESS_PARCEL';
+        $client = new RecordingClient([new Response(400, ['Content-Type' => 'text/plain'], $body)]);
+        $transport = new Transport($client, $this->factory, $this->factory, $this->factory, new NullAuthorization());
+
+        try {
+            $transport->send(new PostalCodeEndpoint('0150'));
+            self::fail('expected BringApiException');
+        } catch (BringApiException $e) {
+            self::assertStringContainsString('HTTP 400', $e->getMessage());
+            self::assertStringContainsString('postal code 1642', $e->getMessage());
+            self::assertStringNotContainsString('no parsable error body', $e->getMessage());
+        }
+    }
+
+    public function testUnparsableErrorBodyRedactsCredentialShapedValues(): void
+    {
+        // If the unparsable body happens to echo credential-shaped values,
+        // they must be redacted before being embedded in getMessage().
+        $body = '{"detail":"unauthorized","api_key":"secretKey","Authorization":"Basic abc"}';
+        $client = new RecordingClient([new Response(401, ['Content-Type' => 'application/json'], $body)]);
+        $transport = new Transport($client, $this->factory, $this->factory, $this->factory, new NullAuthorization());
+
+        try {
+            $transport->send(new PostalCodeEndpoint('0150'));
+            self::fail('expected BringApiException');
+        } catch (BringApiException $e) {
+            self::assertStringContainsString('HTTP 401', $e->getMessage());
+            self::assertStringContainsString('unauthorized', $e->getMessage());
+            self::assertStringNotContainsString('secretKey', $e->getMessage());
+            self::assertStringNotContainsString('Basic abc', $e->getMessage());
+        }
+    }
+
     public function testTransportExceptionWrapsPsr18Failure(): void
     {
         $networkFail = new class ('boom') extends \RuntimeException implements ClientExceptionInterface {