Sorry, I didn't make myself clear. I was fairly certain that those lines are there, I'm just not sure that they are working correctly with MVS. Try printing out the variables to see if they are being set to a proper value. The code that I quoted should evaluate to a non-blank string. Try inserting something like this just before that line: print 'Shipping Method: ' . $order->info['shipping_method']; If that looks OK, try the same thing with $module, which should also produce a string (the module name, or one of them anyway.) If either or both of those are blank the tax will not get added into the final total.   Regards Jim