diff --git a/plugins/woocommerce/changelog/45979-frosso-patch-1 b/plugins/woocommerce/changelog/45979-frosso-patch-1
new file mode 100644
index 00000000000..a85211a9220
--- /dev/null
+++ b/plugins/woocommerce/changelog/45979-frosso-patch-1
@@ -0,0 +1,4 @@
+Significance: patch
+Type: tweak
+
+refactor: `woocommerce_rest_checkout_process_payment_error` returns a `400` response code, instead of `402`.
\ No newline at end of file
diff --git a/plugins/woocommerce/src/StoreApi/Utilities/CheckoutTrait.php b/plugins/woocommerce/src/StoreApi/Utilities/CheckoutTrait.php
index 865ee511f8b..d811207d54b 100644
--- a/plugins/woocommerce/src/StoreApi/Utilities/CheckoutTrait.php
+++ b/plugins/woocommerce/src/StoreApi/Utilities/CheckoutTrait.php
@@ -85,7 +85,7 @@ trait CheckoutTrait {
 				throw new RouteException( 'woocommerce_rest_checkout_invalid_payment_result', __( 'Invalid payment result received from payment method.', 'woocommerce' ), 500 );
 			}
 		} catch ( \Exception $e ) {
-			throw new RouteException( 'woocommerce_rest_checkout_process_payment_error', $e->getMessage(), 402 );
+			throw new RouteException( 'woocommerce_rest_checkout_process_payment_error', esc_html( $e->getMessage() ), 400 );
 		}
 	}