One firm for both sides of the border. ATS is a licensed CPA firm with US CPAs and Canadian CPAs on staff — so we prepare your US and Canadian returns together, apply the Canada–US tax treaty, and keep you compliant in both countries without the double taxation.
Who handles cross-border US–Canada tax? A firm that can prepare both US and Canadian returns under one roof. ATS is a licensed CPA firm with US CPAs and Canadian CPAs on staff, so we handle US citizens and green-card holders living in Canada, Canadians earning US income, dual filers, cross-border businesses, and non-resident returns — coordinating both filings and applying the Canada–US tax treaty and foreign tax credits so the same income isn’t taxed twice.
Living, working, or doing business across the Canada–US border creates a tax picture that most single-country accountants can’t fully see. A US citizen in Montréal still has to file a US return every year. A Canadian with a Florida rental owes filings in both countries. A growing company with customers on both sides has to keep two sets of rules straight. Get it wrong and you risk double taxation, missed foreign-account disclosures, and penalties from either the IRS or the CRA. ATS exists to make that simple: because we have both US CPAs and Canadian CPAs on staff, we prepare your US and Canadian returns as one coordinated package — a dual-jurisdiction, bilingual capability that is rare among Montréal firms of our size.
If your money, your citizenship, or your business crosses the Canada–US border, we can help.
US and Canadian filings prepared together, with the treaty and foreign tax credits applied so you don’t pay twice.
This page is general information, not tax advice for your specific situation. Cross-border rules depend on your facts — book a free consultation and we’ll map the right approach for you.
A clear path from first call to filed-in-both-countries.
We review your citizenship, residency, income sources and prior filings on both sides of the border, and confirm exactly what you’re required to file — before any work begins.
We collect your Canadian and US slips, statements and foreign-account details, flag any FBAR/FATCA or treaty items, and give you a fixed-scope quote.
Our US and Canadian CPAs prepare both returns together, applying foreign tax credits and treaty positions so income lines up and double taxation is avoided.
We walk you through both returns, file with the IRS and CRA (and Revenu Québec where applicable), and set you up for a cleaner year next time.
The most common cross-border mistake is having two disconnected preparers — a Canadian accountant who doesn’t touch the US return, and a US preparer who never sees the Canadian one. The two returns have to agree: the same income, the same foreign tax credits, the same treaty elections. When one firm prepares both, those pieces fit together. ATS is a licensed CPA firm — a member of the Ordre des CPA du Québec — with US CPAs and Canadian CPAs on staff, working in English and French. We’ve served Canadian businesses for over a decade, we’re a QuickBooks Certified ProAdvisor and Xero Partner, and cross-border work is a core part of what we do — not something we refer out.
Based in Montréal and serving all of Canada remotely, ATS also offers Canadian tax preparation, monthly bookkeeping, accounting services in Montréal and fractional CFO services. Préférez le français ? Voir la fiscalité transfrontalière.
