UK Pension Lump Sum US Tax: Reporting the 25% in One Year or Several
Your 25% tax-free cash is tax-free in Britain, but the US return is another matter. Here is how each treaty reading is reported, why no credit arrives, and how one payment compares with phased slices, in pounds and dollars.
Whether the 25% arrives as one payment or in slices decides how many US returns carry it, so settle the timing before the first payment.
Written by the US UK Tax Experts team, cross-border tax specialists
UK pension lump sum US tax: an introduction
The UK pension lump sum US tax question has no settled answer. Britain does not tax your 25% cash. However, the US may. One reading of the treaty exempts it; another says the saving clause lets the US tax it in full. The point is contested. So the cautious course is to report the cash as taxable, or to disclose an exempt position openly.
This article supports our guide to the US-UK double taxation treaty. It is about the US return for the year the money arrives. We cover how each position is written up and why no UK credit comes with the cash. We also show how timing changes the bill. The lump sum allowance itself is mentioned only in passing.
Why UK pension lump sum US tax is a filing question
Most writing stops at the treaty argument. In practice, you still have to fill in a return. Furthermore, each reading leads to different lines, different forms and different records. Moreover, the timing and size of each payment can matter more than the argument does.
Who this article is for
We write for US citizens and green card holders with a UK defined contribution pension. That includes workplace pots and SIPPs. A SIPP is a self-invested personal pension. We also cover British nationals living in the US. By contrast, final salary schemes raise different points, and we leave them aside.
Is the 25% UK tax-free lump sum taxable in the US?
Possibly. Treasury's own explanation of the treaty supports both answers in different passages, so practitioners disagree. For a US citizen, the cautious approach treats the cash as taxable. The alternative is to disclose and defend an exempt position.
The UK starting point
GOV.UK's page on taking tax-free money from a pension allows up to 25% tax-free. In addition, it sets a cap of £268,275 unless you hold a protected allowance. A pension commencement lump sum is tax-free cash taken when you move a pot into drawdown or buy an annuity. An uncrystallised funds pension lump sum, or UFPLS, is a cash withdrawal from an untouched pot. Of each UFPLS, 25% is tax-free and 75% is taxed as income.
The exemption reading
The treaty's Article 17 gives two hooks. Article 17(2) says a UK scheme lump sum paid to a US resident is taxable only in the UK. Separately, Article 17(1)(b) says the residence country must exempt any pension amount the scheme's own country would exempt. Furthermore, Article 1(5) lists 17(1)(b) among the exceptions to the saving clause. The Technical Explanation adds that a US citizen is taxed only on the part the UK taxes. On that reading, your 25% stays exempt.
The saving clause reading
The saving clause is Article 1(4). It lets the US tax its citizens and residents as if the treaty did not exist. Crucially, Article 17(2) is not on the exception list, so it gives a US person nothing. The same Technical Explanation also says paragraph 2, not paragraph 1, deals with lump sums. In addition, it says a US citizen in the UK is subject to US tax on a lump-sum distribution. On this reading, 17(1)(b) never reaches your tax-free cash.
The cautious approach
For UK pension lump sum US tax, neither passage cancels the other, and the treaty does not mention UK tax-free cash by name. Therefore, we prepare the return on the taxable basis unless you choose otherwise with the risks in view. If you take the exempt position, we write it up so the IRS can see exactly what you claimed. Either way, the decision should be yours, made before the cash arrives.
How do you report UK pension lump sum US tax on Form 1040?
On the taxable reading, the cash goes on the pensions and annuities lines of Form 1040. On the exempt reading, you leave it out of taxable income and explain why, usually on Form 8833. Both need the payment converted into dollars at the right rate.
The taxable reading: lines 5a and 5b
No UK provider sends a Form 1099-R, the US slip for pension payments. As a result, you build the figures yourself from the provider's statement. IRS Publication 575 explains lines 5a and 5b for pensions and annuities. Gross pays go on 5a and the taxable amount on 5b. Your cost is your net investment in the contract. Publication 575 excludes amounts withheld from pay on a tax-deferred basis. For most UK workplace pots, cost is small or nil.
The exempt reading: Form 8833
Form 8833 is the IRS form for disclosing a treaty-based return position. The Form 8833 page on irs.gov links the current form. Its instructions require a separate form each year for each position. Notably, those instructions list pension positions taken by an individual among those for which reporting is waived. The waiver appears in Regulations section 301.6114-1(c). Even so, many preparers attach the form anyway as a protective disclosure. Where disclosure is required and missed, section 6712 sets a $1,000 penalty for each failure.
What the disclosure should say
A useful Form 8833 names Article 17(1)(b) and Article 1(5)(a), not just "Article 17". It states the gross payment in pounds and dollars, and the tax-free amount under UK law. It also explains briefly why the saving clause does not apply. Consequently, a reader at the IRS sees the full argument rather than a missing number.
Converting pounds to dollars
The IRS page on foreign currency and exchange rates says to use the rate prevailing on receipt. For example, a single lump sum uses the rate on the payment date. Record the rate and its source on the day, because a few cents per pound moves a six-figure sum noticeably.
Why does UK pension lump sum US tax get no foreign tax credit?
The UK charges no tax on the 25% slice, so there is nothing to credit against the US tax. That gap is what makes the lump sum expensive on the cautious reading.
Nil UK tax means nil credit
The foreign tax credit is a dollar-for-dollar reduction of US tax for foreign income tax on the same income. Specifically, you claim it on Form 1116. The Form 1116 instructions allow a credit for foreign tax paid on a foreign pension lump sum. However, a pension commencement lump sum carries no UK tax. In the UK pension lump sum US tax calculation, that leaves US tax with nothing to offset it.
When carried-forward credits help
UK income tax is often higher than US tax on the same salary. The unused excess can be carried back one year and forward ten, according to the Form 1116 instructions. Credits in the same Form 1116 category may absorb part of the US tax on the cash. Accordingly, your carryover schedule from earlier returns is worth checking before you decide on timing.
UFPLS: the taxed 75% can cover the 25%
An UFPLS behaves differently. The 75% slice is taxed by HMRC, often at 20%. That UK tax counts towards the credit for the whole payment's foreign income in that category. As a result, the UK tax on the taxed slice can shelter the US tax on the tax-free slice. The worked example below shows the effect in figures.
How does one lump sum compare with phased slices on the US return?
One large payment lands in a single US year and climbs the brackets. Phased slices spread the same cash over several years, so more of it falls into the low brackets. We model both ways for clients, and the gap can be large.
A worked example: one payment
Consider a typical case. Claire, a fictional single US citizen aged 60, lives in Bath and has a £400,000 SIPP. She has no other income. We assume £1 buys $1.30. We also use the 2026 US figures throughout: the IRS 2026 brackets and a $16,100 standard deduction. In August 2026 she takes £100,000 as tax-free cash. In dollars that is $130,000, so her taxable income is $113,900. On the cautious reading, her 2026 US tax is about $19,934, and no UK tax exists to credit.
The same cash in four slices
Alternatively, Claire moves £100,000 into drawdown each year from 2026 to 2029. Each year she takes £25,000 of tax-free cash, which is $32,500. Her taxable income is then $16,400 a year. Consequently, she owes US tax of about $1,720 a year, or $6,880 over four years. The IRS indexes thresholds, so holding 2026 figures constant is a simplification. Still, the UK pension lump sum US tax bill falls by roughly $13,000 simply through timing.
The UFPLS version
Instead, suppose Claire takes a £40,000 UFPLS each year. Here £10,000 is tax-free and £30,000 taxable in the UK. Using the 2026 to 2027 UK rates, her £12,570 personal allowance leaves £17,430 at 20%. Her UK tax is £3,486, or about $4,532. Meanwhile, her US tax on the full $52,000 is about $4,060. The credit wipes that out and leaves roughly $472 to carry forward. On this route, her tax-free slice costs her nothing extra in the US.
What the comparison leaves out
The model ignores investment growth, currency movements and her other needs for cash. Furthermore, an UFPLS can trigger the money purchase annual allowance, which limits future contributions, as GOV.UK's annual allowance page explains. On the exempt reading, all three routes give nil US tax on the cash. Each year, though, needs its own disclosure. Therefore, we model the routes side by side so you can choose with the figures in front of you.
Does UK pension lump sum US tax differ for green card holders?
Yes, for some. The saving clause covers US citizens and US residents as the treaty defines them. A person who is neither can sometimes step outside it, but each route has costs.
Green card holders living in the UK
A green card holder is a lawful permanent resident, taxed by the US like a citizen. Living in the UK, you may be resident only there under the Article 4 tie-breaker. In that case, the Form 8833 instructions say you file Form 1040-NR as a nonresident alien with Form 8833 attached. A lump sum from a pension built up through UK work is then generally outside US tax. However, the same instructions warn long-term residents that this claim ends US residency. It may also trigger the exit tax.
British nationals living in the US
A British national living in the US is usually a US resident for the saving clause. So Article 17(2) is blocked for you too. The Article 17(1)(b) argument stays open, though. Its exception from the saving clause applies to everyone. Similarly, the reporting mechanics above apply in full.
Dual citizens
If you hold both passports, you are a US citizen for these purposes. Accordingly, your British nationality does not change the US reading. Our guide to the US and UK tax for retirees covers the wider income picture once you start drawing pensions.
What records and steps does the reporting year need?
You need the provider's paperwork, each payment date's exchange rate and a note of your position. With those in place, the return follows a short sequence.
Records to keep for UK pension lump sum US tax
Keep the provider's crystallisation statement or UFPLS payment advice showing the tax-free and taxable amounts. Additionally, keep the P45 or payslip showing any UK tax deducted. If too much was taken under emergency tax, keep your form P55 refund claim and HMRC's reply. Importantly, a refund reduces the UK tax you can credit, so it matters for the US return. Finally, keep a copy of any Form 8833 for every year it was filed.
Steps before and during the payment
Step one is to decide your treaty position before you instruct the provider. Step two is to check your foreign tax credit carryovers by category. In step three, you choose the size and number of slices with the US brackets in view. Then, on payment day, step four is to record the sterling amount, the split and the exchange rate.
Steps when you prepare the return
Step five is to convert each payment and enter it on lines 5a and 5b. Step six is to attach Form 1116 for any UK tax on the taxed slice. In step seven, you add Form 8833 if you take the exempt position. Lastly, step eight is to report the pension's maximum value on your FBAR. Our article on UK pensions and the FBAR covers that.
How US UK Tax Experts can help
At US UK Tax Experts, the work starts before the payment. We prepare your US and UK returns from one file, so the two agree. For tax-free cash, we work out the US result on both treaty readings. We then model one payment against phased slices and UFPLS, using your own figures. Our UK and US pension service covers the return in the payment year and the disclosures that go with it.
In our experience, the costly mistakes happen before the cash is paid, not on the return. A short review of your UK pension lump sum US tax position first lets you choose the timing knowingly. We also check carryover credits and records, so your US return can be filed with confidence.
Conclusion
Your 25% cash is tax-free in Britain, but the US answer depends on a contested treaty reading. The cautious course is to report it as taxable, or to disclose an exempt position in full. Because no UK tax comes with the cash, there is usually no credit to soften the US bill.
However, timing is the lever you control. One large payment can push you into higher US brackets, while slices spread the cash across several years. An UFPLS can even let the taxed 75% shelter the tax-free 25%. Above all, get the UK pension lump sum US tax position settled before you instruct your provider.
Contact us
Planning to take tax-free cash? Email hello@usuktaxexperts.com or use our contact page. Tell us the pot size, your plans and your citizenship or visa status. We reply within one working day.
Frequently asked questions
Not necessarily, and the point is contested. One reading of Article 17(1)(b) of the treaty exempts it, while the saving clause reading says a US citizen is taxed on it in full. The cautious approach is to report it as taxable or to disclose an exempt position on Form 8833.
Usually not on the tax-free part, because the UK charges no tax on it. You can only credit foreign tax actually paid. However, excess credits carried forward from earlier years, or UK tax on the taxed 75% of an UFPLS, may absorb some of the US tax.
On the taxable reading, it goes on lines 5a and 5b for pensions and annuities. You will not receive a Form 1099-R, so you work the figures out from the provider's statement. Convert the sterling amount at the exchange rate on the payment date.
The Form 8833 instructions list pension positions taken by individuals among those where reporting is waived. Even so, many preparers attach it as a protective disclosure for the UK pension lump sum US tax position, because it records the article relied on. If you take the exempt position, a full disclosure is the safer course.
Spreading it usually gives a lower US bill on the cautious reading, because more of the cash falls into the low brackets each year. In our worked example, four slices cost about $13,000 less than one payment. The right answer depends on your other income, credits and UK plans, so model both ways first.
Generally yes, unless the treaty tie-breaker makes you resident only in the UK and you file as a nonresident with Form 8833. That claim can end long-term resident status and trigger the exit tax. The UK pension lump sum US tax treatment therefore needs weighing against your wider position.
Keep the provider's statement showing the tax-free and taxable amounts, and any payslip or P45 showing UK tax. Also record the exchange rate on the payment date and keep any P55 refund claim. Keep copies of Form 8833 and Form 1116 for each year you file them.
