Form 1116 Explained: The Foreign Tax Credit for Americans Abroad

If you're an American living in the UK, you already know the strange part of US citizenship: you file a US tax return every year no matter where you live. So when you're paying UK tax on your salary and the IRS still wants a return, one question matters more than any other are you about to be taxed twice on the same money? Form 1116 is the answer. It's how you turn the foreign tax you've already paid into a credit against your US tax bill, and for most Americans in the UK it wipes that bill out completely. This article walks you through it in plain language: what Form 1116 is, what it's used for, when you have to file it (and the little-known rule that lets some people skip it), how to complete it, and a full real-world example. Every section starts with a short, direct answer — so you can get what you need fast, then read on for the detail if you want it.

What Is Form 1116?

Form 1116 is the IRS form that individuals, estates, and trusts use to claim the Foreign Tax Credit — the credit that offsets income tax you paid to a foreign country against your US tax.

The United States taxes its citizens and green card holders on their worldwide income, wherever they live. That creates an obvious trap: an American living in London already pays UK tax on their paycheck, so without relief the same dollars would get taxed a second time by the IRS. Form 1116 is the form that lets an individual claim relief from that double taxation.

Think of it as the paperwork that proves your claim. It takes the foreign tax you've paid, applies the IRS's rules and limits, and produces the exact credit you're allowed. You attach it to your Form 1040, and the credit itself lands on Schedule 3.

What Is Form 1116 Used For?

It's used to convert the foreign income tax you've already paid into a dollar-for-dollar credit against your US tax, so the same income isn't taxed twice.

Here's the useful way to think about it. The IRS gives you two ways to lower your bill: a deduction, which shrinks the income you're taxed on, and a credit, which cuts the actual tax you owe. A credit is far more powerful. Form 1116 turns the foreign tax you've paid into that stronger, dollar-for-dollar credit.

Because UK tax rates are generally higher than US federal rates, most Americans in the UK find the credit erases their US tax on that income entirely — and often leaves a surplus to use in another year. In practice, that's what Form 1116 is really for: making sure you pay tax on your income once, not twice.

How Do You Fill Out Form 1116, Line by Line?

Form 1116 has four parts: Part I reports your foreign income and related deductions, Part II lists the foreign taxes you paid, Part III applies the limitation and figures the credit, and Part IV totals it up. You file a separate form for each income basket.

Broken down into plain steps, here's the path through the form:

• Category box at the top — check the basket your income belongs to, usually 'passive' for dividends and interest, or 'general' for a salary.
• Part I, Line 1a — enter your gross foreign income for that category, in US dollars.
• Part I, Lines 2 through 5 — subtract expenses tied to that income, plus a share of deductions like the standard deduction.
• Part II — enter the foreign tax you paid or accrued, using the exchange rate on the date you paid it.
• Part III, Lines 9 through 23 — this is the limitation, which scales your credit so it never tops the US tax on that foreign income.
• Part IV, Lines 25 through 33 — add up the credits from each category. For 2025, the IRS now wants Lines 25 to 32 filled in even if you file just one Form 1116.

One detail trips people up more than any other: currency. The IRS wants every figure in US dollars, converted at the exchange rate in effect on the day you paid the tax (or it was withheld from your pay). For a UK salary taxed through PAYE across the whole year, most preparers use a sensible average rate and keep a written note of the method — the instructions specifically ask you to explain how you converted.

Worked Example: An American in London With a Salary and UK Dividends

If you are a US citizen living in London on a UK salary and you also receive some UK dividends, you would report the salary in the general basket and the dividends in the passive basket, on two separate Forms 1116. Because the UK tax on that income is higher than the US tax on it, the credit will usually eliminate your US bill and leave a surplus to carry forward.

Imagine you are a US citizen who has lived and worked in London for several years. For the 2025 tax year you earn a salary of £60,000, taxed at source through PAYE, and you receive around £3,000 in dividends from a portfolio of UK shares. You have already paid UK tax on both, and now you face your annual US return. The practical question is not whether you must report this income to the IRS — as a US citizen you plainly must — but whether you will end up paying US tax on money the UK has already taxed. This is exactly the problem Form 1116 is designed to solve, and getting the mechanics right is what stands between you owing nothing and overpaying.

Your salary is general category income and your dividends are passive category income, so the two cannot be combined; you work out each on its own Form 1116. Converting at an illustrative rate of around £1 = $1.27, your £60,000 salary becomes roughly $76,200, on which you have paid something in the region of $14,900 of UK tax. The US tax that would otherwise fall on that same salary is far lower — in the order of $9,200 — because US federal rates sit below UK rates at this level of income. The Foreign Tax Credit limitation caps the credit you can use at that $9,200 US figure, which is precisely enough to reduce your US tax on the salary to nil. The remaining UK tax you paid, around $5,700, is not wasted: it becomes a carryover you can hold for up to ten years.

Your dividends work the same way in miniature. The roughly $3,810 of converted dividend income might attract about $570 of US tax, but the UK tax you have already paid on those dividends more than covers it, so no US tax is due on that basket either. The overall result is the one most Americans on a normal UK salary reach once Form 1116 is completed correctly: a US return that reports everything the IRS requires, and a US tax bill of zero, with a useful pool of unused credit carried into future years.

These figures are illustrative and depend on your specific facts, your filing status, and the exchange rates in effect on the dates you pay tax. They are used here to show how the mechanics work, not as a substitute for a calculation on your own numbers.

What Is the Limitation, and How Do the Baskets Work?

The credit is capped at the US tax that would apply to your foreign income — you can't use foreign tax to shelter US income. Income is sorted into 'baskets' (mainly passive and general), and the cap is figured separately for each basket.

The limitation is there for one reason: the credit is only meant to cancel out double taxation, never to wipe out tax on your US-source income. Worked through Part III, the cap is essentially your US tax multiplied by the share of your taxable income that came from that foreign basket. Whatever that produces is the most credit you can claim for that basket in that year.

The baskets matter because you can't blend them. The IRS defines several, but two cover most people: passive category income (dividends, interest, royalties, rents, most capital gains) and general category income (an employee's wages and salary, and active business income). There are also specialist baskets — GILTI under section 951A, foreign branch income, income from sanctioned countries under section 901(j), income re-sourced by treaty, and lump-sum distributions — and each needs its own Form 1116. A UK salary sits in the general basket, UK dividends sit in the passive basket, and that is why the example above needed two forms.

What Are Schedule B and Foreign Tax Credit Carryovers?

If your foreign tax is more than the limitation, the extra isn't lost — you carry it back 1 year and forward up to 10 years. Schedule B (Form 1116) tracks that carryover from year to year.

This is where Americans in the UK quietly build up something valuable. Because UK tax rates run higher than US rates, most people generate more credit than they can use in a single year. That surplus — the roughly $5,700 of leftover UK tax in the example above — becomes a carryover. The IRS lets you carry unused foreign tax back one year, then forward for ten, always used within the same basket.

Schedule B (Form 1116) is the worksheet the IRS uses to reconcile last year's carryover with this year's. If you're bringing credit in from prior years, or building new credit to use later, Schedule B keeps that running balance accurate. It's worth maintaining carefully: a healthy carryover can shelter a future spike in US tax — say, a year you sell an asset or move back to the States.

Should You Use TurboTax or Have Form 1116 Prepared?

Software like TurboTax can produce Form 1116 and is fine for a simple, single-basket case. But the basket rules, the limitation, currency conversion, and carryover tracking are where DIY returns most often go wrong — and those mistakes are expensive.

Consumer tax software handles the easy version well enough: one basket, income on a 1099, and a credit that sits under the limitation. The catch is that Form 1116 is one of the more error-prone forms in the entire US system. The mistakes we see most often are putting a salary in the passive basket instead of general, botching the currency conversion, missing the carryover altogether (which throws away real money), and not realizing a treaty position needs separate handling and sometimes Form 8833.

If your situation is one small dividend, software is fine. But if you have a UK salary, dividends, a pension, rental income, or a carryover worth protecting, having a specialist prepare Form 1116 usually costs far less than the tax at stake — and it guards the carryover balance that a single slip can quietly erase.

Frequently asked questions

Conclusion

If your situation looks anything like the example above — an American in the UK with a salary, some dividends, and maybe a carryover to protect — Form 1116 isn't a form you want to guess your way through. The basket rules, the limitation, and the currency conversion are unforgiving, and the carryover you build up is a genuine asset that one mistake can wipe out. Get it wrong in either direction and it costs you: claim too little and you overpay tax you never owed; claim too much and you invite an IRS adjustment with interest. This is exactly the kind of cross-border calculation where a specialist-prepared Form 1116 pays for itself.