Introduction: Why Treaty Re-Sourcing Decides Your Effective Tax Rate
Treaty re-sourcing stops a wealthy American in Britain paying full US tax and full UK tax on the same dividend. Furthermore, it is the most valuable provision in the US-UK treaty that almost nobody claims correctly. Most cross-border filers understand the foreign tax credit. However, far fewer understand that the credit collapses the moment your income is American rather than British.
The problem is structural. Your US portfolio pays US-source dividends and US-source interest. Britain taxes that income because you live here. Meanwhile, the United States taxes it because you hold a US passport. Consequently, you face two full charges on one income stream. The ordinary foreign tax credit cannot help you.
How Treaty Re-Sourcing Solves the Sourcing Problem
The foreign tax credit only shelters *foreign-source* income. Therefore, UK tax paid on a Wall Street dividend has nothing to offset against on your American return. Treaty re-sourcing repairs that mismatch. Specifically, it deems your US-source income to arise in the United Kingdom, purely so the credit machinery works.
At TaxYork we see the consequences of missing this every filing season. Notably, we rework returns where a client has paid twenty or thirty thousand dollars too much. The cause is almost always the same. Their US-source income sat in the wrong basket. The money is usually recoverable. Nevertheless, recovering it requires understanding exactly what the treaty says.
Who Needs Treaty Re-Sourcing Most
High-net-worth Americans in Britain are the natural candidates. Specifically, investment bankers with US brokerage accounts and founders holding US corporate stock. Executives who kept an American portfolio after relocating face the same issue. Additionally, anyone drawing US pension income while UK resident should examine the position closely.
What Treaty Re-Sourcing Actually Says in Article 24
The authority sits in Article 24 of the 2001 US-UK income tax convention, the relief from double taxation article. Importantly, Article 24 survives the treaty's saving clause. That matters enormously. The saving clause in Article 1(4) lets the United States tax its citizens as though the treaty did not exist. However, Articles 24, 25 and 26 are expressly carved out, so American citizens keep the benefit.
The Exact Wording That Delivers Treaty Re-Sourcing
Article 24(6)(d) states that, for the exclusive purpose of relieving double taxation in the United States, the relevant income "shall be deemed to arise in the United Kingdom to the extent necessary to avoid double taxation." That single sentence is the whole engine. The UK statutory instrument implementing the convention carries identical wording.
Read the qualifier carefully. Treaty re-sourcing operates only "to the extent necessary." Consequently, you cannot re-source your entire American portfolio as a matter of convenience. Instead, you re-source precisely enough income to support the credit you genuinely need.
Article 24(6)(b) and the Restricted UK Credit
Before the American side works, the British side must be settled. Article 24(6)(b) restricts what HMRC must credit. Britain allows only the tax the United States "may impose under the provisions of this Convention on a resident of the United Kingdom who is not a United States citizen." In other words, Britain credits the treaty rate, not your actual US liability.
Those treaty rates are specific. Article 10(2)(b) caps US tax on portfolio dividends at 15 per cent. Article 11(1) makes interest taxable only in the country of residence, so the US rate is nil. Similarly, Article 13(5) assigns gains on securities to the residence state alone. Therefore, HMRC will credit 15 per cent on your US dividends and nothing at all on your US interest.
Category F on Form 1116
On the American return, treaty re-sourcing appears as a separate limitation category. The Form 1116 instructions label it "Certain income re-sourced by treaty," commonly called Category F. Critically, you must file a separate Form 1116 for each treaty country. Additionally, only income the treaty actually re-sources belongs there. The IRS confirms this in its guidance on foreign tax credit special issues.
The Three-Bite Rule Behind Treaty Re-Sourcing
Practitioners describe the Article 24(6) sequence as the three-bite rule. Furthermore, the IRS uses the same language in its technical webinar on income re-sourced by treaty. Understanding the order is essential, because performing the steps out of sequence produces the wrong answer.
Bite One: The Treaty-Rate US Charge
First, the United States takes the tax it could charge a non-citizen British resident. For dividends that is 15 per cent. For interest, royalties and securities gains it is nothing. Importantly, this first bite is protected. Article 24(6)(c) says the American credit "shall not reduce the portion of the United States tax that is creditable against the United Kingdom tax."
Bite Two: The UK Charge After Credit
Second, Britain taxes the income at domestic rates and credits only that first bite. UK dividend rates rose on 6 April 2026 to 10.75 per cent at the basic rate and 35.75 per cent at the higher rate. The additional rate remains at 39.35 per cent, as the government's dividend tax guidance confirms. Meanwhile, interest is charged at ordinary rates reaching 45 per cent.
Bite Three: The Residual US Charge and the Re-Sourced Credit
Third, the United States taxes you as a citizen on the full amount. It then allows a credit for the UK tax you paid after the British credit. This is where treaty re-sourcing does its work. Without it, no foreign-source income exists to support the limitation. Accordingly, the credit would be zero.
A Worked Case Study in Treaty Re-Sourcing
Consider a client we will call a London-based fund principal. They are a US citizen and long-term UK resident, taxed at additional rates. Their US brokerage portfolio produces $120,000 of qualified dividends from US-listed companies. It also pays $40,000 of US corporate bond interest. Assume an exchange rate of $1.27 to the pound.
The Position Without Treaty Re-Sourcing
Britain charges 39.35 per cent on the dividends, which is £37,181. Interest attracts 45 per cent, or £14,173. HMRC then credits the 15 per cent treaty tax on the dividends, worth £14,173. That leaves a net UK charge of £37,181, or roughly $47,220.
America then charges 20 per cent on the qualified dividends and 37 per cent on the interest. Regular US tax reaches $38,800. Additionally, the 3.8 per cent net investment income tax adds $6,080. Because every dollar is US-source, the foreign tax credit limitation is nil. Therefore, the total burden reaches $92,100 on $160,000 of income — an effective rate of 57.6 per cent.
The Position With Treaty Re-Sourcing Claimed Correctly
Now apply Article 24(6)(d). Enough of the income is deemed to arise in Britain to support a Category F credit. The client claims $20,800 of UK tax as a credit, reducing US regular tax from $38,800 to $18,000. That $18,000 floor is the protected first bite, which the credit cannot touch.
The total becomes $18,000 of US regular tax, $6,080 of surcharge and $47,220 of UK tax. That is $71,300 overall. Consequently, the effective rate falls to 44.6 per cent. The client saves $20,800 in a single year. Moreover, the unused $26,420 of UK tax carries back one year and forward ten within the Category F basket.
What the Case Study Proves
The saving came from paperwork, not planning. Nothing about the portfolio changed. Instead, the income simply landed in the correct limitation category on the correct form. In our experience, this pattern repeats across hundreds of US tax returns for Americans in Britain that arrive for review.
Which Income Qualifies for Treaty Re-Sourcing
Not every American dollar qualifies, and misclassification invites an IRS adjustment. Therefore, test each income stream against the treaty separately.
Dividends, Interest and Securities Gains
These are the classic candidates. US dividends, US bond interest and gains on US-listed shares all become re-sourceable. Britain taxes them as your country of residence. Publication 514, the IRS foreign tax credit guide for individuals, sets out the mechanics. Furthermore, the same logic covers US royalties, which Article 12 assigns exclusively to the residence state.
US Real Property and Rental Income
Here treaty re-sourcing fails, and it fails by design. Article 6 gives the United States primary taxing rights over income from American real property. Similarly, Article 13(1) preserves US taxing rights over gains on a United States real property interest. Consequently, Britain must give the credit for that income, not America.
US Social Security and Pension Payments
This area produces the most confusion, and most published guidance gets it wrong. Article 17(3) makes US social security payments taxable *only* in the United Kingdom when you are UK resident. Crucially, that paragraph is carved out of the saving clause. Therefore, the payments escape US tax entirely and never belong in Category F at all. You disclose the position instead, and the Social Security Administration's international pages confirm the payment mechanics.
The Traps That Cost High-Net-Worth Filers Money
Treaty re-sourcing rewards precision. Equally, it punishes assumption. Four traps account for most of the adjustments we see.
The Net Investment Income Tax Cannot Be Sheltered
Article 24(1) allows the American credit "in accordance with the provisions and subject to the limitations of the law of the United States." In *Toulouse v. Commissioner*, decided in 2021, the Tax Court read that exact language as confining the treaty credit to chapter 1 taxes. Accordingly, the 3.8 per cent surcharge survives. Later cases involving other treaties have gone the other way, so the position is contested. Nevertheless, we would not file a UK-treaty return on the assumption that the surcharge is creditable.
The High-Tax Kickout Interferes With the Basket
Passive income taxed abroad above the top US rate of 37 per cent is automatically reclassified into the general basket. The kickout is not elective. Consequently, UK additional-rate tax on interest can move income unexpectedly. Check the interaction with your Category F computation every year.
Form 8833 and the $1,000 Penalty
Section 6114 requires you to disclose treaty positions that override domestic law. You do that on Form 8833. Section 6712 then imposes a $1,000 penalty on individuals for each year you fail to file it. Additionally, an undisclosed position weakens your defence if the IRS later challenges the claim. The Taxpayer Advocate Service publishes useful background on how such disputes escalate.
The Six-Year Departure Rule Runs in Reverse
Article 13(6) lets Britain tax gains realised by someone who was UK resident within the preceding six years. However, Article 24(2)(b) then re-sources those gains *back* to the United States for a resident who has moved to America. The direction of travel flips, and filers who assume the rule is symmetrical claim credits they cannot support. Our cross-border planning team models this before any transatlantic move.
Filing a Treaty Re-Sourcing Claim That Survives Review
A claim is only as strong as its evidence. Therefore, build the file as you go rather than reconstructing it under audit.
Documentation the IRS Expects
Keep the UK tax calculation showing the charge on each income stream, plus proof of payment. Additionally, retain your Self Assessment return and the HMRC statement of account. The HMRC international manual on double taxation relief explains the British computation. Meanwhile, HMRC's guidance on income taxed twice sets out the claim route.
Reconciling Two Different Tax Years
Britain runs to 5 April and America to 31 December. Consequently, the UK tax you paid rarely matches the American year cleanly. You must decide between the paid and accrued methods, and the accrued basis usually aligns better for treaty re-sourcing claims. Importantly, the election binds you in later years.
Amending Earlier Years
If you missed the claim, the position is recoverable. Section 6511(d)(3) gives you ten years from the original due date to claim or adjust a foreign tax credit. That is far longer than the ordinary three-year window. Therefore, filers who discover the issue in 2026 can often reach back to 2016. We routinely pair such amendments with FBAR and FATCA reporting reviews. Where returns were missed altogether, IRS Streamlined Filing becomes the route back. The full list of American treaty partners appears in the IRS treaties A-to-Z index. Professional guidance is also available through bodies such as ICAEW.
How TaxYork Can Help With Treaty Re-Sourcing
We prepare cross-border returns for wealthy Americans in Britain, and treaty re-sourcing sits at the centre of that work. Specifically, we compute the three bites in the correct order. We then allocate income to the right limitation baskets and prepare the supporting Form 8833 disclosure. Furthermore, we reconcile the two tax years so your UK payments land in the right American period.
Our team reviews the whole picture rather than a single form. Accordingly, we test whether your dividends, interest, gains and pension income each qualify. We quantify the credit before we file. Where earlier years were mishandled, we prepare amended returns within the ten-year window. Above all, we tell you the number before you commit.
Conclusion
Treaty re-sourcing converts a punitive double charge into a single, manageable tax bill. The mechanism is written into Article 24(6)(d) and it survives the saving clause. Moreover, it is available to every American citizen resident in Britain. Nevertheless, it works only when the income is correctly identified. The three bites must be taken in order, and the disclosure must be filed.
The case study above saved $20,800 in one year on $160,000 of investment income. Similarly sized savings sit unclaimed on thousands of American returns filed from Britain each year. Ultimately, the difference between 57.6 per cent and 44.6 per cent is not luck. It is preparation.
Contact Us
Speak to a specialist who prepares these claims every week. You can book a consultation with our cross-border team, or email hello@taxyork.com directly. Alternatively, call 020 3488 8606 to discuss your position. We will review your US-source income, quantify the treaty re-sourcing benefit, and confirm whether earlier years should be amended.
Disclaimer
This article provides general information about treaty re-sourcing and the US-UK income tax convention. It does not constitute tax advice for any individual or entity. Tax law changes frequently, and the correct treatment depends entirely on your personal circumstances. Accordingly, you should obtain professional advice before acting on anything set out above. TaxYork accepts no liability for action taken solely on the basis of this article.