US UK Tax Returns Preparation: The Saving Clause Trap
US UK tax returns preparation for dual nationals: how the treaty saving clause cancels most relief, which carve-outs survive, and how to claim credit properly.
For a US-UK dual national, the treaty gives less relief than most expect.
The US-UK treaty does not stop the United States taxing a US citizen. Article 1(4) — the saving clause — lets each state tax its own citizens and residents as if the Convention had not come into effect. Only a short list of provisions in Article 1(5) survives it. Everything else you assumed the treaty gave you, it does not.
This is the single most expensive misunderstanding in US UK tax returns preparation. A dual national with a London home, a UK employment, a SIPP and a portfolio arrives at Jungle Tax holding a settled belief: there is a treaty, so I cannot be taxed twice. The belief is half true. Relief exists — but it comes almost entirely from one article, Article 24, and from the credit mechanics on Form 1116, not from the distributive articles on dividends, interest, gains or employment income that most people imagine protect them.
What does the saving clause actually say?
Article 1(4) of the 2001 UK-USA Double Taxation Convention, as amended by the 2002 Protocol, provides that notwithstanding any provision of the Convention except paragraph 5 of the same Article, a Contracting State may tax its residents (as determined under Article 4) and, by reason of citizenship, may tax its citizens, as if the Convention had not come into effect. You can read the consolidated text on GOV.UK, and the same Article as enacted into UK law in the Double Taxation Relief (United States of America) Order 2002.
Read that carefully. It is not a limitation on abuse, and it is not an anti-avoidance rule. It is a reservation of the entire domestic taxing right. The United States signed a treaty and then, in the fourth paragraph of the first article, wrote itself out of most of it in respect of its own citizens. The Convention is, for a US citizen, a document that mainly governs how the other state must behave.
Why are dual nationals hit hardest?
A non-US person resident in the UK is protected by the treaty in the ordinary way: the distributive articles limit what the US may tax at source, and Article 4 decides residence where both states claim it. A US/UK dual national gets neither comfort. Citizenship-based taxation means the US taxing right never depends on residence at all, so winning the Article 4 tie-breaker does not remove the US return — a point we set out in detail in our guide to the US-UK treaty tie-breaker for dual residents. The tie-breaker can make you a treaty resident of the UK; the saving clause then permits the US to ignore that result and tax you anyway.
So the dual national is not a person with two half-obligations. They are a person with two full obligations, and one narrow set of provisions that reconciles them.
Which provisions survive the saving clause?
Article 1(5) contains the carve-outs, and it is drafted in two limbs that behave very differently. Limb (a) is available to everyone, including a US citizen. Limb (b) is available only to individuals who are “neither citizens of, nor have been admitted for permanent residence in” the state applying the saving clause. That second limb is where most published summaries mislead: they list Articles 19, 20 and 20A among the exceptions without saying that a US citizen cannot use any of them against the United States.
| Provision | Subject matter | Available to a US citizen against the IRS? |
|---|---|---|
| Article 9(2) | Correlative adjustments, associated enterprises | Yes — Article 1(5)(a) |
| Article 17(1)(b) | Pension amounts exempt in the source state | Yes — Article 1(5)(a) |
| Article 17(3) | Social security payments | Yes — Article 1(5)(a) |
| Article 17(5) | Alimony, separation and child support payments | Yes — Article 1(5)(a) |
| Article 18(1) | Deferral of tax on income earned inside a pension scheme | Yes — Article 1(5)(a) |
| Article 18(5) | Deduction for UK pension contributions on the US return | Yes — Article 1(5)(a) |
| Article 24 | Relief from double taxation (the credit article) | Yes — Article 1(5)(a) |
| Article 25 | Non-discrimination | Yes — Article 1(5)(a) |
| Article 26 | Mutual agreement procedure | Yes — Article 1(5)(a) |
| Article 18(2), 19, 20, 20A, 28 | Pension contributions on secondment, government service, students, teachers, diplomatic and consular officers | No — Article 1(5)(b) is limited to non-citizens and non-green-card holders |
| Articles 7, 10, 11, 12, 13, 14, 15, 16, 17(1)(a), 17(2), 22 | Business profits, dividends, interest, royalties, gains, employment, directors, entertainers, pensions generally, lump sums, other income | No — fully overridden by Article 1(4) |
That final row is the whole problem. The articles a wealthy client actually cares about — the ones covering their portfolio, their property gain, their carried interest, their UK employment — are precisely the ones the saving clause switches off.
The lump sum example that proves the point
Article 17(2) says a lump sum from a pension scheme established in one state and beneficially owned by a resident of the other is taxable only in the first-mentioned state. Read alone, that appears to hand a UK-resident US citizen a tax-free UK pension commencement lump sum on both sides. Article 17(2) is not in the Article 1(5)(a) list. It is therefore fully saved, and the United States taxes the lump sum under its domestic rules regardless of the UK exemption. Because the UK charges nothing, there is no UK tax to credit, and the US charge stands naked.
This is the clearest demonstration of the mechanism: the treaty relief is real, but it runs one way only, and it does not run towards the citizen. We deal with the pension consequences in detail across our US tax services work, and it is a routine reason a client who believed themselves protected discovers a large unexpected US liability.
What are the surviving pension provisions genuinely worth?
The carve-outs that do apply to a citizen are not trivial, and they are widely under-claimed on prepared returns:
- Article 18(1) — income earned inside a UK pension scheme is taxed to the individual only when paid out. Without it, a US citizen would face an argument that a SIPP is a currently-taxable foreign arrangement. Because Article 18(1) is carved out of the saving clause, that deferral holds on the US return.
- Article 18(5) — a US citizen resident in the UK who exercises a UK employment borne by a UK employer or UK permanent establishment may deduct or exclude contributions to their UK pension scheme in computing US taxable income. Many prepared returns simply add the employee contribution back into US income. That is a real, recurring overstatement of US tax, and it is recoverable on amendment.
- Article 17(3) — social security paid by one state to a resident of the other is taxable only in the state of residence. For a UK-resident dual national drawing US social security, the charge belongs to HMRC.
How relief actually happens: Article 24, and the ordering rule nobody explains
Because the distributive articles are gone, all the real work falls on Article 24. And Article 24(6) contains the provision that makes the whole system function for a US citizen resident in the UK. It operates as a sequence, and the sequence matters:
- Step one — Article 24(6)(b). The UK, when computing the credit it gives for US tax, takes into account only the amount of tax the US could impose under the Convention on a UK resident who is not a US citizen. In plain terms: HMRC refuses to fund your citizenship. If the treaty would let the US tax a non-citizen UK resident at nil on a given item, the UK gives nil credit, no matter what the IRS actually charged you.
- Step two — Article 24(6)(c). The US then allows a credit against US tax for the UK income tax and capital gains tax paid, computed after the credit given at step one. The US is the residual reliever, not the first.
- Step three — Article 24(6)(d). For the exclusive purpose of making step two work, the income concerned is deemed to arise in the United Kingdom to the extent necessary to avoid double taxation.
Step three is the hinge. A US foreign tax credit under Form 1116 requires foreign-source income. A US citizen with, say, US-source dividends who is resident in the UK would otherwise have UK tax on US-source income and no US foreign-source income against which to credit it. Article 24(6)(d) re-sources that income to the UK so a credit can be claimed. This is why Form 1116 carries a separate category for certain income re-sourced by treaty — and why a return prepared without that category can show tax due that the treaty never intended.
Why is the re-sourced basket so often missed?
Re-sourced income sits in its own limitation category. It cannot be pooled with general or passive category income, which means a separate Form 1116 for each treaty under which income is re-sourced, and a separate limitation computation. Preparers who treat all foreign tax as one pot either lose the credit or create a phantom excess credit that never gets used. The interaction with carryback and carryforward is equally unforgiving; we set out the mechanics in our guide to foreign tax credit baskets and carryovers for US-UK dual filers.
A worked illustration
Consider a UK-resident dual national with UK employment income, a UK-let property, a US brokerage account paying dividends, and a UK pension contribution.
- The UK employment income and UK property income are UK-source. The UK taxes first as state of residence and source; the US taxes under the saving clause and gives credit under Article 24(1) via Form 1116, general and passive categories respectively.
- The US-source dividends are taxed by the US at full domestic rates — the reduced Article 10 rate is unavailable to a citizen, and in any event the saving clause removes it. The UK taxes the same dividends as the resident state, giving credit under Article 24(6)(b) limited to the tax the US could have charged a non-citizen UK resident (in dividend cases, a treaty-rate figure rather than the full US charge). The excess US tax is then relieved by the US itself under Article 24(6)(c), using income re-sourced to the UK by Article 24(6)(d).
- The UK pension contribution reduces UK taxable pay, and under Article 18(5) should also reduce US taxable income — which in turn reduces the US tax the credits have to cover.
Nothing here is exotic. It is simply the correct order of operations, applied consistently across both returns. Applied incorrectly — and it very often is — the same facts produce genuine double taxation on the dividend slice and an overstated US liability on the employment slice.
US and UK side by side
| Question | United States / IRS | United Kingdom / HMRC |
|---|---|---|
| What triggers the filing duty? | US citizenship or green card, wherever you live | UK residence under the Statutory Residence Test, or UK-source income |
| Does the treaty stop the charge? | Generally no — Article 1(4) preserves it | Generally yes for non-residents; the UK also reserves its position over its own residents |
| Primary relief mechanism | Foreign tax credit on Form 1116, by limitation category | Foreign Tax Credit Relief through Self Assessment foreign pages |
| Credit capped at | US tax on the foreign-source income in that category | UK tax on the same income, and the minimum US tax due under the treaty (Article 24(6)(b)) |
| Tax year | Calendar year to 31 December | 6 April to 5 April |
| Disclosure of treaty positions | Form 8833 where required by section 6114 | No equivalent standalone form; disclosed in the return and white space |
| Catch-up route for missed years | Streamlined Filing Compliance Procedures where non-willful | Voluntary disclosure through HMRC’s digital disclosure service |
The mismatched year ends deserve a line of their own. A UK tax year straddles two US tax years, so foreign tax credits rarely map cleanly onto US income. Preparers must decide between the paid and accrued basis and then apply it consistently — an election with long consequences that is easy to make by accident in a catch-up filing.
Do you have to disclose the treaty position on the US return?
Where you take a position that a treaty overrules or modifies US domestic law, section 6114 requires disclosure on Form 8833 unless an exception applies. The IRS explains the form’s purpose on its About Form 8833 page. The regulations list a number of situations where disclosure is mandatory and others where it is waived; claiming a foreign tax credit or the foreign earned income exclusion does not by itself require the form.
Two practical points. First, the penalty for non-disclosure is a fixed statutory amount per failure for individuals, and it is charged per position per year — which compounds unpleasantly across a multi-year catch-up. Second, a Form 8833 is an invitation to read the return. Filing one that asserts a position the saving clause plainly defeats — a common error is a citizen claiming Article 17(2) on a UK lump sum — is worse than filing nothing, because it documents the error in the taxpayer’s own hand.
How do you prepare both returns when US years are missing?
The client this guide is written for usually arrives after the belief has failed: several US years unfiled, UK returns filed and UK tax paid in full, and a growing suspicion that the treaty was never doing the work they thought.
The good news is structural. Because the UK charges tax at rates that in most cases exceed the US charge on the same income, a correctly prepared catch-up frequently produces little or no US tax — the liability is absorbed by Article 24 credits. The exposure is rarely the tax. It is the information returns: FBAR, Form 8938, Form 8621 for non-US funds, Form 5471 where a UK company sits in the structure. Those carry penalties that do not care whether tax was due.
The streamlined route
Where the failure to file was non-willful, the IRS Streamlined Filing Compliance Procedures allow a taxpayer resident outside the United States to file amended or delinquent returns for the most recent three years for which the due date has passed, together with FBARs for the most recent six years, supported by a signed non-willfulness certification. Penalties for the eligible years are waived for those who qualify.
The saving-clause misunderstanding is, in our experience, one of the more credible non-willfulness narratives available — a good-faith misreading of a published treaty is exactly the sort of conduct the procedure contemplates. But the certification must tell the truth, in the taxpayer’s own words, and it must be consistent with what the returns actually show. We handle this end to end through our IRS streamlined filing practice, and the mechanics of running both filings in parallel are covered in our guide to dual-filer return preparation.
The UK side of a catch-up
UK obligations do not pause while US years are corrected. If the missed US years produce a different final US liability, any UK Foreign Tax Credit Relief claimed by reference to US tax may need revisiting. HMRC’s general position on double taxation and credit relief is set out at GOV.UK: if you are taxed twice. Where a client has also been affected by the replacement of the remittance basis with the four-year foreign income and gains regime for arrivals from 6 April 2025, the interaction with US credits should be reviewed rather than assumed — a claim that removes UK tax on an item also removes the credit that was sheltering the US charge on it. Our UK tax services team runs this alongside the US filings rather than after them.
What does the saving clause not defeat?
Two remedies survive, and both are underused by wealthy dual filers:
- Article 25, non-discrimination. Carved out in full. It constrains discriminatory treatment in dealings with residents of the other state.
- Article 26, mutual agreement procedure. Also carved out in full. Where the ordering rules of Article 24 leave genuine unrelieved double taxation — and with re-sourcing limits and mismatched year ends, they sometimes do — the competent authorities can be asked to resolve it. It is slow and formal, but for a large one-off item such as a share disposal or a carried interest realisation, it is a real remedy rather than a theoretical one — and one we assess as part of cross-border tax planning whenever a material item is at stake.
Article 9(2) is worth a mention for founders: where one state adjusts the profits of an associated enterprise, the correlative adjustment obligation survives the saving clause. In a structure with a UK operating company and US shareholders, that is not academic.
The correct mental model
Stop thinking of the treaty as a shield against double taxation and start thinking of it as a set of tie-break and credit rules that assume you are a citizen of only one of the two states. For a dual national, the treaty does three things: it decides residence for its own purposes, it preserves both taxing rights, and it dictates the order in which the two revenue authorities give credit. It does not reduce the number of returns, it does not remove the US charge, and outside the Article 1(5)(a) list it does not exempt a single category of income. Prepared on that basis, the two returns reconcile and the total tax approximates the higher of the two systems rather than the sum. Prepared on the assumption that a treaty prevents double taxation, they do not.
Speak to us before the next filing season
If you are a US/UK dual national with unfiled US years, an unclaimed Article 18(5) pension deduction, or a Form 1116 that has never carried a re-sourced treaty category, the position is almost always fixable — and usually cheaper to fix than clients expect. We prepare both returns together, in the correct order, and we quantify the outcome before you commit to a disclosure route. Our private client and high-net-worth team works exclusively with sophisticated cross-border individuals and their advisers. To review your position in confidence, contact our cross-border team for a discreet, no-obligation consultation.
