Quote Originally Posted by Stevis2002 View Post
Right then. Now I know whats happening.....The vat isn't being added on when somebody uses a discount coupon on the order. This is messing up the orders, but im pretty sure that's what is causing edit orders to play up too. ...
If "tax" is not being calculated correctly when a customer goes through the "checkout" process, something is probably not quite "right" with your tax configuration... I'd start by searching other threads on the forums about setting up taxes and/or vat... Or creating a new thread to ask why your "tax" is not being correctly applied during the "checkout" process.

You need to fix all issues with "taxes" during the "checkout" process before you will be able to tackle any issues with "tax" calculation when editing an order.