This PHP code checks if the product id is in cart and if so, removes all other shipping methods leaving free shipping as the selected option. If no free shipping method has been added to the zone, it creates one.
add_filter( 'woocommerce_package_rates', 'wpsites_show_only_free_shipping_for_specific_product', 20, 2 );
function wpsites_show_only_free_shipping_for_specific_product( $rates, $package ) {
$target_product_id = 6455; // 🔹 Replace with your product ID
$product_in_cart = false;
// Check if the target product is in the cart
foreach ( $package['contents'] as $item ) {
if ( $item['product_id'] == $target_product_id ) {
$product_in_cart = true;
break;
}
}
// If the product is in the cart → remove all shipping methods except free shipping
if ( $product_in_cart ) {
$free_shipping_available = false;
// Keep only free shipping if it already exists
foreach ( $rates as $rate_id => $rate ) {
if ( 'free_shipping' !== $rate->method_id ) {
unset( $rates[$rate_id] );
} else {
$free_shipping_available = true;
}
}
// If no free shipping method exists in the zone, create one dynamically
if ( ! $free_shipping_available ) {
$rates = array();
$rates['custom_free_shipping'] = new WC_Shipping_Rate(
'custom_free_shipping',
__( 'Free shipping', 'woocommerce' ),
0,
array(),
'custom_free_shipping'
);
}
}
return $rates;
}The reason you need to use this code rather than the shipping settings is because shipping methods do not enable you to add shipping classes.
Code Installation
Add the code to the end of your child themes functions file or code snippets plugin.
Usage
Swap out the product ID 6455 on line 3 of the code to match your free shipping product.
Free Shipping & Custom Shipping Labels Plugin
This plugin enables you to assign free shipping per product and taxonomy term. You can also customize the shipping label per product and per term as well.
Leave a Reply