Add vat over the commission

// Add 16% VAT to vendor commission 

add_filter( 'wcv_process_commission', 'my_wcv_commission_rate', 10, 5 );

add_filter( 'wcv_commission_rate', 'my_wcv_commission_rate', 10, 5 );

function my_wcv_commission_rate( $commission, $product_id, $product_price, $order, $qty ) {

	$vat_fee = 0.16;

	$marketplace_split = $product_price - $commission; 

	$vat = $marketplace_split * $vat_fee;

	$commission -= $vat; 

	// if there is a negative number then make it 0; 

	if ( $commission < 0 ) $commission = 0;

	// Round commission so it doesn't break gateways

	$commission = round( $commission, 2 );

	// Return commission 

	return $commission;

}