Because the final consumption of the goods is not in within Canada. Therefore GST will not apply when you invoice your USA customer. However, because the sales took place in canada and your US customer paid you. Your company will have to pay the tax on the profit that you made as a income to your company.

Majority of them them comes to Toronto by rail. In this case. they normally be customs cleared in Toronto. Some LCL shipment. because not all the goods inside are for Toronto. In these cases. Te container will be destuffed in vancouver and then truck up to Toronto. These case. The goods can be cleared in vancouver. The same goes for Halifax. But the majority in high percentage are from Vancouver. There are some from New York also.

Titus