How to Add Fee Based on Product Category and Shipping Method in WooCommerce?

By adding fees based on certain parameters, store owners can better reflect real-world costs associated with certain products and shipping methods. The below code snippet can help to add fees based on product category and chosen shipping method in WooCommerce.

add_action( 'woocommerce_cart_calculate_fees','ts_custom_category_fee');
function ts_custom_category_fee( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;
    
    $chosen_shipping_method_id = WC()->session->get( 'chosen_shipping_methods' )[0];
    $chosen_shipping_method    = explode(':', $chosen_shipping_method_id)[0];

    // Set HERE your categories (can be term IDs, slugs or names) in a coma separated array
    $categories = array('50');
    $fee_amount = 0;

    // Loop through cart items
    foreach( $cart->get_cart() as $cart_item ){
        if( has_term( $categories, 'product_cat', $cart_item['product_id']) )
            $fee_amount = 35;
    }
    
    // Only for Local pickup chosen shipping method
    if ( strpos( $chosen_shipping_method_id, 'free_shipping' ) !== false || strpos( $chosen_shipping_method_id, 'filters_by_cities_shipping_method' ) !== false ) {
        // Loop though each cart items and set prices in an array
        foreach ( $cart->get_cart() as $cart_item ) {
            // Get product id
            $product_id = $cart_item['product_id'];

            // Quantity
            $product_quantity = $cart_item['quantity'];

            // Check for category
            if ( has_term( $special_fee_cat, 'product_cat', $product_id ) ) {
                $total += $fee_per_prod * $product_quantity;
            }
        }

    // Adding the fee
    if ( $fee_amount > 0 ){
        // Last argument is related to enable tax (true or false)
        WC()->cart->add_fee( __( "Additional Fees", "woocommerce" ), $fee_amount, false );
    }
}
}

Output

When products from the ‘Electronic’ category are added to the cart and if the chosen shipping method is ‘Free shipping’ an extra fee of $35 is added to the cart totals.

Alternatively, you can also add WooCommerce Checkout fees based on shipping method and payment method.