diff --git a/modules/ppcp-api-client/src/Entity/PurchaseUnit.php b/modules/ppcp-api-client/src/Entity/PurchaseUnit.php
index ad138cc75..f2c64c73a 100644
--- a/modules/ppcp-api-client/src/Entity/PurchaseUnit.php
+++ b/modules/ppcp-api-client/src/Entity/PurchaseUnit.php
@@ -211,6 +211,15 @@ class PurchaseUnit {
 		return $this->custom_id;
 	}
 
+	/**
+	 * Sets the custom ID.
+	 *
+	 * @param string $custom_id The value to set.
+	 */
+	public function set_custom_id( string $custom_id ): void {
+		$this->custom_id = $custom_id;
+	}
+
 	/**
 	 * Returns the invoice id.
 	 *
diff --git a/modules/ppcp-button/src/Endpoint/CreateOrderEndpoint.php b/modules/ppcp-button/src/Endpoint/CreateOrderEndpoint.php
index 686b87dd8..39a848433 100644
--- a/modules/ppcp-button/src/Endpoint/CreateOrderEndpoint.php
+++ b/modules/ppcp-button/src/Endpoint/CreateOrderEndpoint.php
@@ -258,6 +258,12 @@ class CreateOrderEndpoint implements EndpointInterface {
 			} else {
 				$this->purchase_unit = $this->purchase_unit_factory->from_wc_cart( null, $this->handle_shipping_in_paypal );
 
+				// Do not allow completion by webhooks when started via non-checkout buttons,
+				// it is needed only for some APMs in checkout.
+				if ( in_array( $data['context'], array( 'product', 'cart', 'cart-block' ), true ) ) {
+					$this->purchase_unit->set_custom_id( '' );
+				}
+
 				// The cart does not have any info about payment method, so we must handle free trial here.
 				if ( (
 					in_array( $payment_method, array( CreditCardGateway::ID, CardButtonGateway::ID ), true )