Code-Snippets-Functions/Execute a function on a child site/WooCommerce/add-percentage-increase-all-shipping-rates.txt

add_filter('woocommerce_package_rates', 'increase_shipping_costs', 10, 2);
function increase_shipping_costs( $rates, $package ) {
    $rate_multiplier = 1.65; //  65% increase cost
    
    // Loop through shipping rates
    foreach ( $rates as $rate_key => $rate ) {
        
        if ( 'free_shipping' !== $rate->method_id && $rate->cost > 0 ) {
            $has_taxes = false; // Initializing
            $taxes     = array(); // Initializing

            $rates[$rate_key]->cost = $rate->cost * $rate_multiplier; // Set new rate cost
            
            // Loop through taxes array (change taxes rate cost if enabled)
            foreach ($rate->taxes as $key => $tax){
                if( $tax > 0 ){
                    $taxes[$key] = $tax * $rate_multiplier; // Set the new tax cost in the array
                    $has_taxes   = true; // Enabling tax changes
                }
            }
            // set array of shipping tax cost
            if( $has_taxes ) {
                $rates[$rate_key]->taxes = $taxes;
            }
        }
    }
    // For a filter hook, always return the main argument
    return $rates; 
}