Snippet to add handling charge in percent to WooCommerce Shipping Cost based on WooCommerce Shipping method and WooCommerce Shipping Zone. PluginHive Plugins supported - https://www.pluginhive.com/product/multiple-carrier-shipping-plugin-woocommerce/, https://www.pluginhive.com/product/woocommerce-ups-shipping-plugin-with-print-label/, https://w…

functions.php

/**
 * Snippet to add handling charge in percent to to shiiping cost based on shipping method and shipping zone. Use * to define for all the remaining zone.
 * Created at : 09 July 2018
 * Updated at : 18 July 2018
 * PluginHive Plugins : https://www.pluginhive.com/plugins/
 * Gist Link : https://gist.github.com/xadapter/b52eae8ba6d8f8d60513f31bb4cbc630
 */

add_filter( 'woocommerce_package_rates',function( $shipping_rates ){

	$handling_fee_based_on_zone = array(
		array(
			'zone_ids'		=>	array( 11, 5, 7),					// Zone id array
			'adjustment'	=> 10,									// Adjustment in percent
		),
		array(
			'zone_ids'		=>	array( 1, 2, 4 ),
			'adjustment'	=>	100,
		),
		'*'	=>	array(												// For all other remaining zone
			'zone_ids'		=>	array('rest_shipping_zones'),
			'adjustment'	=>	200,
		),
	);

	$shipping_method = array('wf_woocommerce_shipping_pro', 'flat_rate');		// Shipping methods to which handling fee need to be added

	$destination = array(
		'country'	=> WC()->customer->get_shipping_country(),
		'state' 	=> WC()->customer->get_shipping_state(),
		'postcode'	=> WC()->customer->get_shipping_postcode(),
	);

	// Get the matching zone
	$zone = WC_Shipping_Zones::get_zone_matching_package(
		array(
			'destination' => array(
				'country'  => $destination['country'],
				'state' => $destination['state'],
				'postcode' => $destination['postcode'],
			)
		)
	);
	$zone_id 	= $zone->get_id();

	$selected_key = null;
	if( ! empty($zone_id) ) {
		foreach( $handling_fee_based_on_zone as $key => $data ) {
			if( in_array($zone_id, $data['zone_ids']) ) {
				$selected_key = $key;
			}
		}
	}

	if( $selected_key === null ){
		$selected_key = '*';
	}

	if( ! empty($handling_fee_based_on_zone[$selected_key]) ) {
		foreach( $shipping_rates as $shipping_rate ) {
			$method_id = $shipping_rate->get_method_id();
			if( in_array( $method_id, $shipping_method) ) {
				$cost = (float) $shipping_rate->get_cost();
				$new_cost = $cost + ( $cost * $handling_fee_based_on_zone[$selected_key]['adjustment'] / 100 );
				$shipping_rate->set_cost($new_cost);
			}
		}
	}
	return $shipping_rates;
});