add_filter('woocommerce_add_to_cart_validation', function($valid, $product_id, $qty, $variation_id = null, $variations = []) { // new => old $key_map = [ 'pa-your-window-size' => 'pa-select-your-window-size', 'pa-wall-mount-options' => 'pa-select-wall-mount-options', 'pa-type-of-room' => 'pa-select-type-of-room', 'pa-wall-directions' => 'pa-select-wall-directions', 'pa-rod-type' => 'pa-select-rod-type', ]; foreach ($key_map as $new => $old) { $n = 'attribute_' . $new; $o = 'attribute_' . $old; if (isset($_POST[$n]) && !isset($_POST[$o])) { $_POST[$o] = $_POST[$n]; // provide the value where Woo expects it } } return $valid; }, 10, 5);