Cross-Border Tax Accountant in Ottawa: Ontario Guide

A cross-border tax accountant in Ottawa prepares your Canadian and US returns together, so the treaty claims and foreign tax credits match on both. Ottawa adds its own set of questions: what happens to a federal public service pension once you live in the US, whether you file as an Ontario or a Quebec resident if you live on the Gatineau side, OHIP when you leave, Ontario’s Estate Administration Tax, and stock options for tech workers moving south. How to choose any cross-border accountant is in what to look for in a cross-border tax accountant.

What does a cross-border tax accountant do in Ottawa?

They file your Canadian return with the right provincial calculation and your US return, and they make the two agree on what each country taxes. In Ottawa the mix leans toward government pensions, federal employees posted abroad, and tech-sector equity, alongside the usual departure-tax and account-reporting work.

Your situation	Canadian side	US side	Read next
Retired public servant moving to the US	Non-resident withholding on the pension, capped by the treaty	Pension on the US return, with a foreign tax credit for Canadian tax	Canadian employer pension received in the US
Canadian federal employee posted to the US	Salary taxed in Canada	Generally not taxed by the US if you’re a Canadian citizen doing government work	US-Canada tax treaty
Tech worker moving to the US with options	Option income split by days of employment in Canada	Generally all of it on the US return if you’re a US resident at exercise, with a foreign tax credit for the Canadian share	Cross-border stock options and RSUs
Ottawa family moving to Washington or Austin	Departure-year return and deemed disposition	First-year US return	Moving from Ottawa to Washington DC

The Toronto version of this guide covers the rest of Ontario’s rules for movers: cross-border tax accountant in Toronto. The decisions and dates around a move are in cross-border tax planning.

How is a federal public service pension taxed in the US?

As a pension under the treaty, taxed by the US where you live, with Canada allowed to tax it too up to a cap. The treaty’s government service article covers remuneration “other than a pension,” so a government pension falls under the pension article instead (Canada-United States Tax Convention Act, Schedule I, Article XIX).

Under that pension article, Canada can tax a pension that arises there, but if a US resident is the beneficial owner of a periodic pension payment, the tax can’t exceed 15% of the gross payment (Article XVIII(2)(a), same source). That cuts Canada’s usual 25% Part XIII rate on pensions paid to non-residents (CRA, Non-residents of Canada). The US side has a limit too: any part of the pension Canada would exclude from income for a Canadian resident is exempt in the US (Article XVIII(1), as replaced by the 1983 protocol, same source).

The foreign tax credit is claimed on Form 1116. After you leave, the CRA also lets non-residents elect under section 217 to report certain Canadian pension income on a return instead of leaving the withholding as final tax (CRA, Non-residents of Canada). CPP and OAS are a separate question, covered in how CPP and OAS are taxed if you live in the US.

Federal employees posted to the US

A Canadian citizen posted to the US to do government work generally stays taxable on that salary only in Canada. The treaty says remuneration, other than a pension, paid by a country to a citizen of that country for services in the discharge of functions of a governmental nature is taxable only in that country (Canada-United States Tax Convention Act, Article XIX).

There’s a carve-out. If the work is in connection with a trade or business the government carries on, the ordinary employment article applies instead (same article). Citizenship is part of the test, so a dual citizen or a locally hired non-citizen needs a closer look before relying on it.

Do I file in Ontario or Quebec if I live in Gatineau?

You file by where you live on December 31, and work location doesn’t change that. The CRA tells filers to use the package for the province they resided in on December 31, 2025. A Quebec resident on that date uses the federal-only package and files a separate Revenu Québec return (CRA, 2025 income tax and benefit guide).

So a Gatineau resident commuting to an Ottawa office files as a Quebec resident, and an Ottawa resident working in Gatineau files as an Ontario resident. If you had residential ties in more than one province on December 31, the CRA says to use the package for the province where your most important ties are (same page). The provincial rate table follows the same December 31 rule (CRA, 2026 tax rates).

The year you leave Canada is the exception: you use the province you lived in on the day you left (CRA, Leaving Canada).

What are Ontario’s 2026 tax rates and health premium?

Ontario’s 2026 brackets run from 5.05% on the first $53,891 of taxable income to 13.16% on income over $220,000 (CRA, 2026 tax rates). The Ontario Health Premium sits on top, from $0 at taxable income of $20,000 or less to $900 above $200,600 (Ontario, Health premium).

2026 taxable income	Ontario rate	Federal bracket	Federal rate
Up to $53,891	5.05%	Up to $58,523	14%
$53,891 to $107,785	9.15%	$58,523 to $117,045	20.5%
$107,785 to $150,000	11.16%	$117,045 to $181,440	26%
$150,000 to $220,000	12.16%	$181,440 to $258,482	29%
Over $220,000	13.16%	Over $258,482	33%

The two sets of brackets are separate, so read each pair of columns on its own. Ontario also adds a surtax on top of these rates: 20% of the Ontario tax above one threshold plus another 36% of the Ontario tax above a second, which were $5,710 and $7,307 for 2025 (Form ON428, 2025). At high incomes that lifts the top Ontario rate from 13.16% to about 20.5% (13.16% times 1.56). Ontario says the health premium isn’t linked to OHIP and doesn’t affect your eligibility for care. It’s usually withheld from pay or pension along with income tax, and otherwise paid with your return (same Ontario page). Ontario’s HST is 13% (CRA, GST/HST rates).

What happens to OHIP when you move to the US?

It ends after a short window, generally 90 days after the move, once you give ServiceOntario your new address and move date. Ontario says that if you’re cancelling your health card because you’re moving outside Ontario, give ServiceOntario your new address and move date as soon as possible, so OHIP continues for the allowable time, generally 90 days, after the move (Ontario, Replace, cancel or change information on your health card).

You can do that by phone, by mailing a Change of Information form, or at a ServiceOntario centre (same page). For trips rather than moves, Ontario recommends private health insurance before you leave the province (Ontario, OHIP coverage outside Ontario). How OHIP compares with the Alberta and BC plans when you leave is in provincial health insurance when you leave Canada.

How are stock options split when I move to the US?

By days. For options granted to you as an employee, the 2007 diplomatic notes annexed to the treaty say the income is treated as earned in each country in proportion to the days between grant and exercise on which your principal place of employment was in that country (Canada-United States Tax Convention Act, Schedule I, Annex B, paragraph 6).

So an Ottawa engineer whose option ran 1,000 days from grant to exercise, 750 of them based in Ottawa and 250 in Austin, has 75% of the option income allocated to Canadian employment and 25% to US employment (750 ÷ 1,000 = 75%). The two tax authorities can agree to a different split if the option was really a transfer of the shares at grant, for example because it was in the money (same note). RSUs, and how each country times the income, are in cross-border stock options and RSU taxation.

How much is Ontario probate (Estate Administration Tax)?

Nothing on an estate worth $50,000 or less, and $15 for every $1,000 above $50,000, with the value rounded up to the next thousand (Ontario, Estate administration tax). There’s no cap. On an $800,000 estate: ($800,000 − $50,000) ÷ $1,000 × $15 = $11,250.

What counts includes bank accounts at foreign banks. What doesn’t includes RRSPs, RRIFs and TFSAs with a beneficiary designation, jointly owned assets that pass automatically to the other owner, and real estate outside Ontario (same page). So a Florida condo isn’t in the Ontario number. An Estate Information Return is due within 180 calendar days after the estate certificate is issued. Ways to reduce the tax, and how they interact with US estate rules, are in Ontario probate fees and avoidance strategies.

Next steps

Before you meet an accountant, gather your pension statement, your option and RSU grant schedule, the date you expect to stop living in Ottawa or Gatineau, and last year’s returns. Those four set the province, the pension withholding, the option split and the departure-tax picture. If you’re heading for Texas, the corridor guide is moving from Ottawa to Austin.

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.