Do I need a US company to sell to American customers?
Often not, and plenty of businesses sell into the United States for a long time without one. What changes the answer is not the volume of sales on its own but the presence you build up: an employee on the ground, stock held in a warehouse, a contractor with authority to conclude contracts on your behalf, or crossing a state's economic nexus threshold. Any of those can create an obligation. The mistake is to treat the absence of a US entity as the absence of US obligations. They are different questions, and the second one is decided by what you do, not by what you have incorporated.
Does the Canada US tax treaty protect me from state sales tax?
No, and this catches sellers out regularly. The treaty governs federal income tax, where the question is whether you are carrying on a US trade or business and whether you have a permanent establishment. State sales tax runs on a separate track: nexus is tested under each state's own rules and those rules ignore the treaty entirely. So you can be protected federally and registrable in several states at the same time. In practice the first US obligation a foreign seller acquires is usually a state one, which is why the state analysis should not wait for the federal answer.
When does hiring a US salesperson create a US tax problem?
The salesperson matters most when they can bind you. A person who habitually plays the principal role leading to the conclusion of contracts in your name is treated very differently from one who gathers enquiries and passes them to head office for approval. That distinction is a treaty test, so it turns on what the person actually does rather than on their job title or on whether they are an employee or a contractor. Look at the authority in the contract and at the practice in real life. If those two differ, it is the practice that will be examined.
Does keeping stock in a US warehouse create tax obligations?
It can, and it is worth separating the two systems again. For federal purposes, holding inventory is part of the picture that decides whether you are carrying on a US trade or business and whether you have a permanent establishment under the treaty. For state purposes, inventory sitting in a state is one of the classic nexus triggers in its own right, regardless of the treaty. Third-party fulfilment makes this harder to see, because stock can be moved between locations without anyone telling you. Ask your provider where your goods physically are, and keep the answer.
What counts as a permanent establishment for a Canadian seller?
It is the treaty threshold that decides whether the United States can tax your business profits, and it is applied to facts rather than to paperwork. Selling to US customers from Canada, on its own, does not usually reach it. What reaches it is presence in the country: premises you operate from, people acting for you who can conclude contracts in your name, and activity with enough substance behind it that the business is genuinely being carried on there. Because the test is factual, what your people and premises actually do matters more than how the arrangement is described in a contract. That is why records of who went where, and what they agreed while they were there, do most of the work in any review.
Can we owe tax in a state we have never visited?
Yes. State nexus is not only about physical presence. A state can test it on economic activity alone, measured against its own threshold, so a seller with no people, no premises and no stock in a state can still cross into a registration obligation purely on what it sells there. Each state sets its own rules, so the answer is per state rather than for the United States as a whole, and the treaty does not come into it. The practical consequence is that the review has to be run from sales records by destination, period by period, rather than from a list of places anyone has been. Sellers who test only physical presence usually find the economic thresholds were crossed some time earlier.
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.
