Who pays the GST when my goods arrive in Canada?
The importer of record does. Duty and import tax are assessed at the border on the customs value of the shipment, and they are charged to whoever is shown as the importer on the entry — commonly through a customs broker, who then bills it on. That is a separate matter from the tax on the onward sale to your Canadian customer, which is worked out under the domestic rules on the price you charge. Two charges, two bases, two moments in the transaction. Sellers who see one number arrive from a broker and assume it has dealt with everything usually find the domestic side untouched.
Can I recover the GST paid at the border without a Canadian company?
Recovery does not turn on having a Canadian company; it turns on being registered appropriately. A non-resident that imports as importer of record can recover the import tax where its registration supports doing so, and cannot where it holds none. This is the decision most often made by default: the shipment has to clear, somebody is named on the entry, and the tax follows that name. If the party named cannot recover it, the charge simply becomes a cost of the sale. Settle the registration question before the first shipment moves rather than after a broker invoice raises it.
Should I or my Canadian customer be the importer of record?
It is a commercial choice with a tax consequence, and the consequence runs one way: who is shown as importer of record decides who can recover which charge. If your customer imports, the import tax lands with a party that can usually recover it, but your customer takes on the clearance, the paperwork and the exposure to a valuation query. If you import, you keep control of the border process and can quote a cleared delivered price, but you need your own registration in place for the tax to be recoverable. Decide it deliberately, put it in the shipping terms, and instruct the broker to match.
Is customs duty the same thing as import tax?
No. They are separate charges that happen to arrive on the same shipment and often on the same broker invoice. Duty depends on what the goods are and where they come from, and it is a cost. Import tax is a tax on bringing the goods in, assessed on the customs value, and whether it is a cost or a recoverable amount depends entirely on who imported and how they are registered. Treating the broker total as a single expense buries a potentially recoverable amount inside a genuine cost. Split the entry documents into their components before anything is posted to the accounts.
Do I charge Canadian tax on the sale as well as at the border?
The onward sale is taxed under the domestic rules, independently of what happened at the border. So a shipment can attract duty and import tax on its customs value on entry, and the sale to the Canadian buyer can then be taxable on the price charged. This is not the same amount counted twice: the base is different, and where the importer is properly registered the border amount is recoverable while the tax on the sale is charged to the customer. The mistake to avoid is treating the border charge as having settled the sale. Work out the two obligations separately, then reconcile them.
Why did my shipment attract tax at the border and on my invoice?
Because those are two different charges. One is assessed on the customs value when the goods cross, and it belongs to whoever is named as importer. The other arises on your supply to the Canadian customer, under the domestic rules, on what you charge them. They sit at different points in the transaction and they are worked out on different figures. Whether you are worse off overall depends on the recovery position of the importer of record, which in turn depends on registration. If nobody in the chain can recover the border amount, it is the arrangement that is worth revisiting rather than the invoice.
Is moving money between my own accounts in two countries taxable?
Moving your own capital between your own accounts is not itself income, so the transfer is not what creates tax. What can create tax or reporting is the income the money earned before it moved, a foreign-exchange gain on certain holdings, and the reporting obligations the balances themselves trigger — foreign account and asset reports keyed to balances rather than income. Remittances out of some countries also need certification before the bank will send them. See foreign account reporting.
How do I actually stop being taxed twice?
In this order. Fix your residence under each country's own rules, and if both claim you, apply the treaty tie-breaker. Identify where each type of income is sourced. Read the article that covers that income type, because it decides who taxes and at what maximum rate. Then claim the relief on the residence-country return, with proof of the foreign tax. Most of the tax people lose to double taxation is lost at the last step, not the first. See how double taxation is relieved.