Living, working, or owning property on both sides of the US-Canada border makes your taxes more complicated than they need to be. Two countries each want to know about your worldwide income, the rules don't always line up, and one mistake can mean filing in two places, paying tax twice, or both. This page is the entry point to a series of plain-English explainers on how the cross-border rules actually work in practice.
tk.cpa is registered with the Canada Revenue Agency as a non-resident representative. If you are an existing or prospective client, you can authorize tk.cpa through CRA's Represent a Client portal to retrieve your T-slips (T4, T5, T4A, NR4), view your Notices of Assessment, and communicate with the CRA on your behalf. Most US-based tax practices cannot do this. We can.
To get started, contact tk.cpa.
You probably came here because one of these describes you:
The articles below cover what you actually need to know, written for people who want to understand the rules, not just nod along to a tax accountant.
One thing worth understanding before you go deeper: the US and Canada take fundamentally different approaches to taxing their people.
The US taxes citizens no matter where they live. If you have a US passport or green card and you move to Toronto, you still file a US tax return every year. Even if you have not set foot in the US for a decade. This is why FBAR, Form 8938, and Form 8854 (the exit form) exist.
Canada taxes residents no matter their citizenship. A Canadian who genuinely moves to the US stops being a Canadian tax resident on the date of departure. They file a final part-year return, pay departure tax on certain assets, and they're done. A non-Canadian who comes to Canada and stays becomes a tax resident, regardless of whether they're a citizen.
The result: a US citizen in Canada often has to file in both countries on the same income, and use the treaty plus foreign tax credits to avoid being taxed twice. A Canadian who has fully left does not have an ongoing Canadian filing obligation, but a US citizen who has fully left the US still does.
If you are a US citizen or green card holder, you have a US filing obligation every year you have income above the threshold, period - regardless of where you live. If you are a Canadian by citizenship who has clearly moved away, you generally don't have an ongoing Canadian filing obligation. The key word is "clearly" - and that's where the residency rules in the next article come in.
Here are the names that come up in cross-border conversations, in plain English:
T1. The Canadian individual income tax return. Equivalent to Form 1040 in the US. Filed with the CRA, due April 30 (or June 15 if self-employed - but any tax owed is still due April 30).
T2. The Canadian corporation income tax return. Equivalent to Form 1120 in the US. Due six months after the corporation's fiscal year-end.
T1135. Canada's foreign property reporting form. Triggered when foreign property cost more than $100,000 CAD at any time in the year. Full guide.
NR4. The Canadian information slip for non-resident income (interest, dividends, pension paid to non-residents). Roughly equivalent to a 1042-S in the US.
NR73. Determination of residency form, used when leaving Canada. Optional - and not always advisable to file.
NR301 / NR302 / NR303. Forms a non-resident files with the Canadian payer to claim treaty-reduced withholding rates.
Form 8833. The US form for taking a treaty position - "I'm relying on Article IV of the US-Canada treaty to be a non-resident for US tax purposes" type things. Required for many cross-border claims.
Form 8840. The Closer Connection Statement, used by snowbirds in the US for fewer days than the Substantial Presence Test would otherwise require taxation.
Cross-border returns are not a side project. They benefit from someone who understands both the US and Canadian rules in detail and can coordinate the timing of elections, the foreign tax credit baskets, and the matching of T-slips to 1099s.
tk.cpa's CRA non-resident representative status means we can:
For most cross-border clients, having one practice handle both sides eliminates the most common source of cross-border tax errors: each country's preparer assuming the other side handled something.
To engage tk.cpa for cross-border work, visit tk.cpa and use the contact form. Existing clients who want to authorize CRA Represent a Client access can request the authorization workflow during onboarding.