Foreign Tax Credit Carryforward and Carryback: Ten Years Forward, One Back, and Only Within the Basket

Short version: Form 1116 Explained: The Foreign Tax Credit for Individuals

Americans living in Canada pay more Canadian tax on their employment income than the US would charge, and the foreign tax credit is limited to the US tax on that income. The excess is not lost: it carries back one year and forward ten, within the same category of income. Over a decade in Canada, a US citizen can accumulate a large general-basket carryforward that becomes valuable the year they move to a no-tax state and have foreign income the credit can offset. The carryforward is also the reason the foreign tax credit beats the foreign earned income exclusion in Canada: the exclusion produces nothing to carry.

Key takeaways

• Limitation: the credit in each basket is limited to the US tax on foreign-source income in that basket (the limitation fraction: foreign-source taxable income over worldwide taxable income, times US tax).
• Carryover: excess credit carries back one year and forward ten years, within the same basket, on Form 1116 and its carryover schedule.
• Baskets: general (employment, business), passive (interest, dividends, rents, gains), and others (foreign branch, GILTI, treaty-resourced). Credits do not cross baskets.
• Canada's side: the Canadian foreign tax credit for non-business income tax cannot be carried forward; unused amounts may be deducted under section 20(11) or 20(12). The business foreign tax credit carries back three years and forward ten.
• Using the carryforward: it offsets US tax on future foreign-source income in the same basket, which for a general-basket carryforward means future foreign employment or business income, not US wages.

The limitation

The foreign tax credit cannot exceed the US tax that would have applied to the foreign-source income. For an American in Canada with $110,000 USD of Canadian wages and no other income, the limitation is the full US tax (all income is foreign-source), roughly $18,000, and the Canadian tax of about $31,000 USD produces about $13,000 of excess. For one with $110,000 of Canadian wages and $50,000 of US-source investment income, the general-basket limitation is the US tax attributable to the $110,000 (about two-thirds of total US tax), and the passive basket has its own limitation on the US-source income (zero, because it is not foreign-source).

Carryback and carryforward

Excess credit in a basket is first carried back to the preceding year (amending that return if it had unused limitation) and then forward to each of the ten following years, applied in order. The carryforward is tracked on the Form 1116 carryover reconciliation and must be reported each year; credits older than ten years expire.

A carryforward is usable only in a year with excess limitation in the same basket: a year in which US tax on foreign-source income in that basket exceeds the foreign tax paid on it. An American who lives in Canada for ten years and returns to the US with a $150,000 general-basket carryforward can use it only against US tax on foreign general-basket income in the following years. If they take a US job and have no foreign earned income, the carryforward sits unused and expires. If they take a job in Singapore or Dubai (low or no tax), the carryforward eliminates US tax on that income for years.

The baskets

General limitation: employment income, self-employment income, most business income. Passive: interest, dividends, rents, royalties, capital gains. Separate baskets exist for foreign branch income, GILTI, and treaty-resourced income (income that a treaty allows the taxpayer to treat as foreign-source, such as US-source income of a Canadian resident who is a US citizen). A US citizen in Canada with Canadian employment income (general) and US dividends (US-source, not creditable) and Canadian dividends (passive) has three separate computations.

The high-tax kickout moves passive income taxed by the foreign country at a rate above the highest US rate into the general basket, which can help an American in Canada whose Canadian dividend income is taxed at high Canadian rates.

Canada's side

Canada allows a foreign tax credit for non-business income tax paid to another country, limited to the Canadian tax on that foreign income, on Form T2209 (federal) and T2036 (provincial). Unused non-business foreign tax credit cannot be carried forward; the taxpayer can instead deduct the foreign tax under section 20(11) (foreign tax above 15% on property income) or 20(12) (foreign tax not credited). A Canadian resident with US-source income taxed by the US at a higher rate than Canada would charge loses the excess as a credit but may deduct it. Business foreign tax credit carries back three years and forward ten.

Worked example

A US citizen lives in Toronto from 2016 to 2025, earning $150,000 CAD a year, and accumulates about $12,000 USD of general-basket excess credit per year: roughly $120,000 by 2025, with the 2016 amount expiring after 2026.

• 2026: moves to Florida, takes a US job. No foreign general-basket income; carryforward unused; the 2016 layer expires.
• 2026 alternative: moves to Dubai, takes a job at $200,000 USD. No Dubai income tax; US tax on the wages about $40,000; the general-basket carryforward offsets it entirely; repeats for three years until the carryforward is exhausted.
• 2026 alternative: moves to Florida, keeps a Canadian consulting contract worth $60,000 USD. Canadian tax on the consulting income (if taxable in Canada under Article VII with a fixed base) creates new credits; the carryforward offsets US tax on that foreign income.

Official sources

"If you paid or accrued foreign taxes to a foreign country or U.S. possession and are subject to U.S. tax on the same income, you may be able to take either a credit or an itemized deduction for those taxes." — Internal Revenue Service, Foreign Tax Credit, https://www.irs.gov/individuals/international-taxpayers/foreign-tax-credit

"If you have foreign taxes available for credit but you cannot use them because of the foreign tax credit limit, you may be able to carry them back to the previous tax year and forward to the next 10 tax years." — Internal Revenue Service, Foreign Tax Credit – How to Figure the Credit, https://www.irs.gov/individuals/international-taxpayers/foreign-tax-credit-how-to-figure-the-credit

"You may be able to claim the foreign tax credit if you paid foreign income or profit taxes on income you earned outside Canada and reported on your Canadian tax return." — Canada Revenue Agency, Line 40500 – Federal foreign tax credit, https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/deductions-credits-expenses/line-40500-federal-foreign-tax-credit.html

Practitioner note

The carryforward is an asset that most Americans in Canada do not know they have and most preparers do not track. We reconcile it every year on the Form 1116 schedule, and we tell clients what it is worth when they consider a move: a decade of excess Canadian credits can make the first years in a low-tax country US-tax-free.

See also: Planning a move? Start with the Canada-to-US tax checklist and browse every corridor by city, province, and state.

Next step

Fairlight prepares the Form 1116 computations by basket, the carryover reconciliation, and the planning to use accumulated credits after a move. See cross-border pricing or book a call.