In Canada, exports are "zero-rated" sales for K.S.T. purposes. This means that any time you ship a product to someone outside Canada, you don't charge Grams.S.T. Yet, you get declare (or deduct from the G.S.T. collected by you) all the "input tax credits" (G.S.T. that you paid for business purposes) to make that upload. The idea, I suppose, is to encourage dispatching.