Do I need to register for GST/HST as a non-resident?
Registration for a non-resident turns on two questions: whether you are carrying on business in Canada, and what kind of supply you are making. Neither is answered by where your company is incorporated or where its bank sits. Carrying on business is judged on the substance of your activity here, including where contracts are concluded, where stock sits, whether people act for you in Canada, and how much of the operation touches the country. The nature of the supply then decides whether it is taxable, exempt or zero-rated. A business can be carrying on business here and still collect very little, and a business with no presence at all can still owe registration on digital supplies.
Is GST the same thing as HST?
They are the same federal tax collected under two labels. GST is the federal tax applied on its own. HST is the federal tax harmonised with a participating province's sales tax and collected as a single amount at a combined rate. You register once and file one return either way. What changes is the rate you charge, and that follows the place of supply rather than where your business sits, so a single national contract can carry different rates for different customers. Provinces outside the harmonised system run their own separate sales taxes, which are not part of this registration at all.
Does a treaty protect me from Canadian GST/HST?
No. Income tax treaties allocate taxing rights over profits and income; they say nothing about sales tax. A business can be fully protected from Canadian income tax by a treaty and still be required to register, charge and remit GST/HST on its Canadian supplies. This is the most common way a foreign seller's first Canadian tax obligation arrives: the income tax question was considered, answered reassuringly, and the indirect tax question was never asked. Test the sales tax position separately, on its own rules, and do it before supplies begin rather than after a threshold has been crossed.
What happens if I should have registered years ago?
The exposure is the tax you should have collected, not merely a penalty, because the obligation to remit does not depend on having charged the customer. That is why an unregistered period is expensive: the tax comes out of your margin unless your contracts let you go back to customers, which they often do not. Deal with it by fixing the start date first, then quantifying the periods, then choosing between a voluntary correction and waiting. Registering from today and hoping the earlier years are not examined leaves the liability in place and forfeits whatever relief a disclosure might have secured.
Can I claim back the GST/HST I paid on Canadian costs?
Only if you are registered, and only under a route that allows recovery. Tax paid on business inputs is recoverable by a registrant against the tax it collects, so a business with substantial Canadian costs usually wants a registration that permits that. Some registration routes for non-resident suppliers deliberately do not, trading simplicity for the loss of recovery. Before choosing a route, add up what you actually bear tax on here, including warehousing, professional fees, local services and tax at the border, because that figure rather than the ease of filing is what decides which route is right for you.
Do I charge GST/HST on sales to customers outside Canada?
Often not, but that is a conclusion to be reached rather than assumed. Exports of goods and certain services supplied to non-residents can be zero-rated, meaning taxable at a nil rate: you charge nothing and you keep the right to recover tax on your inputs. Zero-rating depends on conditions, and the evidence that those conditions were met is yours to hold. Keep the shipping and destination documents, and record who the customer was and where they were when the supply was made. An export treated as zero-rated with nothing in the file to prove it is an assessment waiting to happen.
How do you avoid double taxation?
You claim relief once, in the right country, in the right order. Usually the source country taxes first, the residence country then gives a credit for that tax against its own charge on the same income, and a treaty caps the source-country rate. Getting the order wrong is what produces a double charge you then have to unwind. The mechanism differs by income type, which is why we map the whole position before filing either return. See how to avoid double taxation.
I have not filed for several years while living abroad — what are my options?
Both countries have routes back, and using one before they contact you is what preserves the relief. On the US side there are procedures aimed at taxpayers whose failure was not wilful, including one designed for people living outside the country, and separate procedures for late account reports and information returns alone. Canada has its voluntary disclosures programme and taxpayer relief for penalties and interest. Filing quietly and hoping is the one approach with no protection attached to it. See catch-up filing.
