Form 1116: baskets, carryovers and the credit that saves expats most

Figures relate to tax year 2025 (US)

Form 1116 is how you claim the foreign tax credit on a US return. It converts tax you paid to HMRC into a dollar-for-dollar reduction of your American bill. For most Americans in Britain, it is the single most valuable form in the package, because UK rates run higher than US ones.

It is also the form people fill in worst. Baskets get mixed, carryovers get lost, and credits that should have banked for a decade simply vanish. So this guide covers the limitation, the baskets, and how to keep every dollar of relief you earned.

Key takeaways

• The credit offsets US tax dollar for dollar, up to a limit based on your foreign income share.
• Income sits in separate baskets — mainly general and passive — and each needs its own form.
• Unused credits carry back one year and forward ten, but only within the same basket.
• You elect either paid or accrued treatment, and the choice binds future years.
• A small credit can skip the form entirely under the de minimis election.

What is Form 1116?

It is the IRS form that computes your foreign tax credit and the limit on it. You report foreign income by category, the foreign tax paid on it, and the resulting credit. The IRS page for Form 1116 (opens in a new tab) carries the form and its instructions.

The underlying idea is fairness rather than generosity. America taxes its citizens worldwide, so without relief two countries would tax the same salary. The credit prevents that. It does not, however, refund foreign tax or reduce US tax on US income.

How is the credit limited?

The limitation is the heart of the form. Your credit cannot exceed the US tax attributable to your foreign income. In practice you multiply your total US tax by the share of income that came from abroad, and that product caps the credit for the year.

This is why high UK tax rarely creates a US refund. According to the IRS foreign tax credit guidance (opens in a new tab), excess credits above the limit cannot be refunded. Instead they carry to other years, which makes tracking them genuinely valuable.

What are the baskets, and why do they matter?

Baskets are categories of income, and credits never cross between them. UK tax on salary cannot offset US tax on passive income, however unfair that feels. Each basket you use needs its own Form 1116, filed alongside the others. The IRS treats them as separate calculations sharing one return.

The general and passive split does most of the damage in practice. A salaried expat builds surplus general credits year after year, while a small dividend bill sits unrelieved in the passive basket. The two never meet, and the surplus expires quietly after ten years.

A credit in the wrong basket is not a credit. It is a number waiting ten years to disappear.

How do carryovers work?

Unused credit carries back one year, then forward up to ten. The carryover stays inside its own basket throughout. Each year you use current credits first, then the oldest carryover, which keeps the oldest amounts from expiring unnecessarily.

Carryovers only survive if somebody tracks them. They live on a schedule attached to the return, and a new preparer who never receives the prior years simply starts at zero. In our practice we see six-figure carryover balances rebuilt from old returns, and just as often lost forever.

Paid or accrued: the election that binds you

You choose whether to claim credits when foreign tax is paid or when it accrues. Paid is simpler and suits people whose UK tax settles through PAYE. Accrued matches the tax to the year that generated it, which usually aligns the two systems better.

The mismatch between tax years makes this decision matter. The UK year ends 5 April; the US year ends 31 December. Accruing helps align them, but once you elect accrual you must keep using it. So decide deliberately in the first year rather than drifting into it.

How do you complete Form 1116 correctly?

The mechanics reward order. Sort the income before touching the form, because almost every serious error starts with income in the wrong category. Then work through the sequence below, one basket at a time:

1. Sort each item of foreign income into its basket — general, passive or another category.
2. Convert income and tax to dollars, using consistent rates for the whole year.
3. Allocate deductions against foreign income, because they reduce the limitation.
4. Compute the limitation: total US tax multiplied by the foreign share of income.
5. Apply current-year credits first, then the oldest carryover in that basket.
6. Carry any excess back one year and forward ten, recorded on the schedule.
7. File a separate Form 1116 for each basket you use, and keep the workings.

When can you skip the form?

A de minimis election lets you claim small credits directly on the return. Broadly it applies when your creditable foreign tax is $300 or less, or $600 for joint filers, and all the income is passive with proper statements. It saves real time for people with a modest UK savings account.

The trade-off is invisible but real. Skipping the form means no carryover schedule, so any excess simply disappears. Anyone building surplus credits should file properly instead, however small this year's number looks. A quiet year today can fund relief in a much noisier one later.

Exchange rates: the detail that quietly moves the number

You report every figure in dollars, so the rate you pick shapes the credit. Most filers use the yearly average rate for salary and steady income. For one-off events, such as a bonus or a property sale, the spot rate on the day usually fits better.

Whichever approach you take, apply it consistently across income and tax within the same year. Mixing a spot rate for the tax and an average rate for the income distorts the ratio. Keep a short note of the rates you used, because that note answers most follow-up questions instantly.

Which deductions reduce your limitation?

Deductions that relate to foreign income lower the foreign share, and a lower share means a smaller limitation. So you apportion the standard deduction, mortgage interest and charitable gifts. Many self-prepared returns skip this step and overstate the credit as a result.

The allocation rules run long, but the principle is short. Ask which income a deduction supports. Split it accordingly, then carry the foreign portion into the limitation. Doing this properly costs an hour and protects the whole claim.

A worked example

Take an illustrative example. An American in Bristol earns £70,000 of salary and £2,000 of UK bank interest during 2025. Her UK tax on the salary comfortably exceeds the US charge, so her general basket produces surplus credits after wiping the US tax on that income.

Her interest sits in the passive basket. The UK taxed it lightly, so the passive credit falls short of the US tax on it, leaving a small balance due. Her surplus general credits cannot help, because baskets never mix. She pays a little US tax while carrying thousands of unusable credits forward.

The mistakes and penalties that waste credits

Most Form 1116 problems cost money quietly rather than triggering letters. That makes them easy to repeat for years. These are the errors we correct most often:

• Lumping all foreign income into the general basket, which overstates relief and misstates the return.
• Losing carryover schedules when changing preparer, and restarting a ten-year clock at zero.
• Forgetting to allocate deductions, which inflates the limitation and invites adjustment.
• Using inconsistent exchange rates across income and tax within the same year.
• Taking the de minimis shortcut while sitting on excess credits worth banking.
• Claiming credit for UK tax that was refunded later, without amending the year.

One more trap deserves its own line. Credits cannot be claimed on income you excluded under the earned income exclusion, because no double relief exists on the same dollars. We cover that interaction in the guide to Form 2555 and the exclusion, and the choice between the two routes deserves real modeling in year one.

Does the treaty change any of this?

It underpins it. The US-UK treaty obliges each country to relieve double taxation, and the credit is how America delivers on that promise. In specific cases the treaty also re-sources income, which can move it into a basket where your credits actually work.

Those re-sourcing positions need care and usually disclosure. Our guide to the US UK tax treaty sets out what survives the saving clause, because a re-sourcing claim that fails leaves the original problem untouched.

How US UK Tax Accountants helps

We prepare Form 1116 basket by basket, with carryover schedules maintained year to year rather than rebuilt in a panic. Our US federal returns service covers the whole return, and because we also handle the UK side, the foreign tax figures come from filings we prepared ourselves.

One senior specialist owns the file, on a fixed fee agreed in writing before any work begins. When we take on a new client, we check historic carryovers first. Recovering them often pays for the engagement outright, and it takes one careful pass through the prior returns.

Protect the credits you have earned

If nobody can tell you your carryover balance by basket, you are probably wasting it. Tell us what you hold and where you file. We will rebuild the position, prepare Form 1116 properly, and quote a fixed fee in writing. Book a consultation and hear back within one working day.

Last reviewed 8 September 2026 by the US UK Tax Accountants Tax Team. This article is general information, not personal tax advice — speak to a qualified US/UK tax adviser about your own position.

For the neighbouring question, The child tax credit abroad: how American parents in Britain claim the refund walks through it in detail.