Recently I was contacted by a user of our PayPal for WooCommerce extension to inform me of a bug in the plugin. Custom fees were not getting included in the cart totals. As such, PayPal would return an invalid cart totals error upon checkout. Doh!

I needed a quick way to easily add custom fees to the shopping cart so that I could test this issue and get it resolved, which has been done as of our 1.1.3 version update.

I was provided with the following snippet to do just that. Simply placing this in my child theme’s functions.php file causes a $2.00 fee to be applied to all orders.

// Add Fee to all products
function woo_add_cart_fee()
	global $woocommerce;
	$additional_fee_name = "Service Fee";
	$extra_fee = 2;
	$additional_fee_taxable = true;
	$addedFee = false;
	// first check to make sure it isn't already there
	foreach ( $woocommerce->cart->get_fees() as $_fee ) 
		if ($_fee->id == sanitize_title($additional_fee_name) ) 
			$_fee->amount = (float) esc_attr( $extra_fee );
			$_fee->taxable = $additional_fee_taxable;
			$addedFee = true;
	if (!$addedFee) 
		$woocommerce->cart->add_fee( __($additional_fee_name, 'woocommerce'), 
                              $extra_fee, $additional_fee_taxable );
add_action( 'woocommerce_before_calculate_totals', 'woo_add_cart_fee' );

Of course, this can be manipulated to handle any sort of custom fee you might need to add to your orders, and I found it very useful for testing and troubleshooting the fees.