Introduction: The 1031 Exchange and the Atlantic Divide
A 1031 exchange lets an American investor sell one property, buy another, and defer the entire capital gain. Furthermore, the relief is generous, well established, and survived the 2025 tax reforms untouched. However, it carries a devastating flaw for Americans living in Britain that almost no guidance mentions.
The flaw is simple. Britain does not recognise the deferral. Consequently, HMRC charges capital gains tax on the swap immediately and in cash. Meanwhile, no US tax exists to credit against it. At TaxYork we have seen clients pay six-figure UK bills on transactions their American adviser described as tax-free.
This guide explains exactly how the relief works. Furthermore, it shows why section 1031(h) blocks the transatlantic swap most people want. Additionally, it sets out how the timing mismatch converts a 1031 exchange into permanent double taxation, and which planning routes still function.
Why a 1031 Exchange Appeals to Americans in Britain
Many wealthy Americans in London retain US rental property from before they moved. Typically, that property carries a large embedded gain and years of accumulated depreciation. Therefore, selling outright triggers a substantial federal bill.
Naturally, a 1031 exchange looks like the answer. Additionally, the investor keeps the capital working rather than surrendering a quarter of it to tax. Nevertheless, the analysis that works perfectly for an American in Boston breaks down entirely for the same American in Belgravia.
What the Relief Actually Does
The relief defers rather than forgives. Specifically, the gain rolls into the basis of the replacement property and surfaces on a later sale. The IRS guidance on like-kind exchanges confirms the mechanism, and section 1031 of the Internal Revenue Code supplies the statutory basis.
Importantly, deferral is not exemption. Consequently, the gain remains alive indefinitely, waiting for a disposal that does not qualify. That distinction becomes critical once a second tax authority enters the picture.
How the Rules Work Before You Cross a Border
The mechanics are strict, and the deadlines are unforgiving. Furthermore, failure at any stage collapses the whole transaction into a taxable sale.
The 45-Day and 180-Day Deadlines
Two clocks start on completion of the sale. The Form 8824 instructions require replacement property to be designated in writing no later than 45 days after you transfer the property you gave up. Subsequently, you must receive that property by the 180th day, or by your return due date including extensions, whichever falls earlier.
Both periods of a 1031 exchange run concurrently rather than consecutively. Moreover, weekends and holidays count. Therefore, a 1031 exchange demands replacement targets lined up before the first sale completes.
Real Property Only Since 2018
The Tax Cuts and Jobs Act narrowed the relief sharply. Consequently, exchanges of machinery, vehicles, artwork, collectibles and intellectual property no longer qualify. Only real property held for investment or business use survives.
Notably, the 2025 reforms left this position alone. Specifically, repeated proposals to cap deferrals at $500,000 failed, so no dollar limit, income limit or transaction limit applies in 2026. Therefore, the relief remains fully intact for real estate.
The Qualified Intermediary Requirement
You may never touch the sale proceeds. Instead, a qualified intermediary holds the funds between the two transactions. Accordingly, the instructions treat a properly structured deferred exchange through an intermediary as a like-kind exchange.
However, related parties cannot act as intermediary. Furthermore, your own accountant or solicitor is generally a disqualified person. Therefore, appoint an independent professional intermediary before marketing the property.
Section 1031(h): You Cannot Swap a US Property for a London Flat
Here the first cross-border wall appears, and it stops most plans dead.
The Statutory Bar on Transatlantic Swaps
The IRS states the position without qualification. Real property in the United States is not like-kind to real property outside the United States. Consequently, section 1031(h) blocks any attempt to sell a Florida rental and roll the proceeds into a Kensington flat.
Therefore, the 1031 exchange most Americans in Britain actually want is simply unavailable. Moreover, no structuring fixes it, because the bar is geographic rather than technical. Many clients arrive convinced otherwise, having read general American guidance written for a domestic audience.
Foreign-to-Foreign Exchanges Do Qualify
A genuine concession exists in the other direction. Specifically, foreign real property is like-kind to other foreign real property. Consequently, an American could exchange a Manchester rental for a property in Spain and defer the US gain.
Furthermore, the two properties need not sit in the same country. Nevertheless, this concession helps far fewer people than it appears to, for the reason set out next.
Why That Concession Rarely Helps a UK Resident
The US deferral is worthless if Britain taxes the same transaction anyway. Consequently, a UK-resident American using a 1031 exchange between two UK properties achieves nothing in net terms. HMRC charges the gain immediately, and the American simply loses the foreign tax credit that a straightforward sale would have generated.
Therefore, the foreign-to-foreign route suits Americans living outside the United Kingdom in low-tax jurisdictions. Meanwhile, for a UK resident it usually makes the position worse rather than better.
The HMRC Problem: Britain Taxes the Swap Immediately
This section contains the point that costs clients the most money, and it appears almost nowhere online.
No UK Rollover Relief for Investment Property
Britain has a rollover relief, but it does not reach investment property. HMRC's Capital Gains Manual at CG60250 sets out the conditions under sections 152 to 159A of the Taxation of Chargeable Gains Act 1992. Critically, the taxpayer must carry on a trade. Furthermore, both the old and new assets must be used only for that trade.
Consequently, a buy-to-let or a commercial investment holding fails at the first condition. Therefore, no UK equivalent to a 1031 exchange exists for the properties investors actually hold.
The Timing Mismatch That Destroys the Credit
HMRC treats the exchange as a disposal at market value on the day it completes. Accordingly, UK capital gains tax on the 1031 exchange falls due for that tax year in the ordinary way. Meanwhile, the US gain sits deferred, so there is no American liability against which to claim relief.
Consequently, the client pays real UK tax in cash at the precise moment the foreign tax credit is unavailable. Furthermore, current UK rates run at 18% within the basic rate band and 24% above it from 6 April 2026. Additionally, the annual exempt amount is only £3,000. Therefore, the immediate cost of a 1031 exchange is substantial.
What Happens When the US Gain Finally Crystallises
Years later the replacement property sells, and the deferred American gain arrives at last. However, Britain taxed that economic gain long ago. Consequently, no UK liability exists in the later year to absorb the US charge. Moreover, no mechanism carries the earlier UK tax forward to meet it.
Therefore, the 1031 exchange converts a creditable transaction into genuine double taxation. In our experience, this is the single most expensive misunderstanding in US-UK property planning, and it is entirely avoidable with advice taken before completion. Proper tax treaty planning has to model both years together rather than each in isolation.
Currency, Depreciation and Two Different Base Costs
Even where the headline analysis is right, the two computations rarely match.
Sterling Gains the IRS Never Sees
Britain computes the gain in sterling. Specifically, HMRC converts the acquisition cost at the exchange rate on purchase and the proceeds at the rate on sale. Consequently, a dollar-flat transaction can still produce a large sterling gain when the pound has weakened between the two dates.
Therefore, currency movement alone creates UK tax on economic profit the American computation never recognises. Accordingly, a 1031 exchange must be modelled in both currencies, using the Treasury reporting rates of exchange and the IRS yearly averages as appropriate. Additionally, HMRC guidance on foreign income and gains confirms that UK residents report worldwide gains. Therefore, the US location of the property offers no shelter.
Unrecaptured Depreciation at 25%
American landlords must claim depreciation, and it reduces basis whether or not they took the deduction. Consequently, a long-held rental carries substantial unrecaptured section 1250 gain, taxed at up to 25% rather than the ordinary long-term rate.
However, Britain grants no depreciation on residential investment property at all. Therefore, the UK base cost stays at original cost while the US basis falls year by year. Accordingly, the two gains diverge steadily. Consequently, a 1031 exchange leaves the American figure larger than the British one.
The State Clawback Most Londoners Never Hear About
Federal analysis is only half the American picture. Notably, several states track deferred gains long after the taxpayer leaves. California is the sharpest example, and many of our London clients once owned Californian property.
Where a Californian property is exchanged for replacement property in another state, the Franchise Tax Board preserves its right to tax the deferred Californian gain. Consequently, the taxpayer must file FTB Form 3840 for the year of the exchange and every year afterwards, until the gain is finally recognised.
Critically, that duty continues even after you move to London and stop filing Californian returns entirely. Therefore, an American in Britain can carry an annual state filing obligation from a 1031 exchange completed a decade earlier. Furthermore, California grants no relief under the US-UK treaty, so the eventual state charge sits outside the credit system altogether.
Reporting Deadlines on Each Side
A 1031 exchange still requires a US filing. Specifically, you report it on Form 8824 with the return for the year of transfer, even though no tax falls due.
Meanwhile, the UK charge goes through Self Assessment. Notably, the 60-day online property reporting service applies only to UK land and property, so a US disposal does not use it. Therefore, the UK tax is payable by the following 31 January, which at least buys planning time.
Who FIRPTA Actually Catches
Confusion about withholding sends many clients down the wrong path entirely.
US Citizens Are Not Foreign Persons
The Foreign Investment in Real Property Tax Act imposes withholding on dispositions by foreign persons. However, an American citizen remains a US person regardless of where they live. Consequently, FIRPTA withholding does not apply to a US citizen selling American property from London.
Therefore, clients should resist advisers who raise withholding as an obstacle to a 1031 exchange. Moreover, guidance aimed at non-resident aliens simply does not describe their position.
Where Withholding Genuinely Bites
Withholding matters when the seller genuinely is foreign. Specifically, a British spouse holding property in their sole name, or a non-US entity, falls squarely within the rules. Consequently, joint ownership structures need checking carefully before any sale.
Additionally, a 1031 exchange by a foreign person can still proceed, though the withholding interacts awkwardly with the intermediary arrangements. Therefore, mixed-nationality couples should take advice well before marketing.
A Worked Case Study With Real Numbers
Consider Sarah, a 51-year-old US citizen who has lived in London since 2019. She is UK resident and domiciled for tax purposes. She retained a Miami rental bought in 2014 for $600,000. In 2026 she agrees a sale at $1,500,000 and her US adviser proposes a 1031 exchange into a Texas apartment block.
The US Position
Sarah claimed depreciation of roughly $209,000 over twelve years, reducing her adjusted basis to $391,000. Consequently, an outright sale would produce a total gain of $1,109,000. That splits into $209,000 of unrecaptured depreciation taxed at 25%, producing $52,250, and $900,000 of long-term gain at 20%, producing $180,000.
Furthermore, the investment income surcharge adds roughly $42,000. Therefore, an outright sale costs approximately $274,000 in US federal tax. Understandably, deferring that figure through a 1031 exchange looks extremely attractive.
The UK Position
Britain ignores the deferral completely. Specifically, HMRC treats the exchange as a disposal at market value in the 2026 to 2027 tax year. Sarah's UK base cost is the full $600,000 purchase price, because Britain grants no depreciation relief.
Converting at illustrative rates of $1.65 on acquisition and $1.32 on disposal gives a sterling cost of £364,000 against proceeds of £1,136,000. Consequently, the UK gain is £772,000. After the £3,000 annual exempt amount, £769,000 falls chargeable at 24%, producing £184,560.
The Real Cost
Sarah therefore owes £184,560 to HMRC by 31 January 2028, in cash, on a transaction her adviser called tax-free. Moreover, she has no US liability that year to credit, because the 1031 exchange removed it.
Subsequently, when she sells the Texas building in 2033, the deferred $274,000 of US tax finally arrives. However, Britain taxed that gain seven years earlier, and nothing carries the 2026 UK payment forward. Consequently, Sarah pays both charges in full on one economic gain.
Had she simply sold outright, the US tax of roughly $274,000 would have arisen in the same year as the UK charge. Accordingly, treaty relief would have eliminated most of the duplication. Ultimately, the deferral cost her more than the tax it deferred.
Planning Routes That Still Work
The position is difficult rather than hopeless, and several routes genuinely help.
Aligning the Two Charges in One Year
The core fix is timing. Specifically, if the American gain and the British gain land in the same tax year, the foreign tax credit works as intended. Therefore, an outright sale often beats a 1031 exchange for a UK resident, despite appearances.
Furthermore, the treaty gives the United States the primary taxing right over US real property gains, with Britain granting credit. Consequently, aligning the years usually leaves only the excess of the UK rate over the American one.
Exchanging Before or After UK Residence
Residence status changes everything. Specifically, an American who completes a 1031 exchange while still non-UK resident escapes the immediate British charge entirely. Similarly, an American planning to leave Britain may prefer to wait.
Nevertheless, the statutory residence test and temporary non-residence rules are unforgiving. Therefore, never rely on a departure date without confirming the position formally.
Getting the Filings Right on Both Sides
Accurate reporting protects the credit position for years afterwards. Accordingly, keep the intermediary agreement, the identification notice, completion statements and exchange rate evidence for both dates. Moreover, retain depreciation schedules, because the divergent base costs must be reconstructed later.
Where a past 1031 exchange went unreported, correction may be needed. In those cases the IRS Streamlined Filing Compliance Procedures sometimes provide the route, and our IRS Streamlined Filing service handles the catch-up. Additionally, undisclosed foreign accounts frequently surface alongside property issues, so FBAR and FATCA reporting needs reviewing at the same time.
Professional guidance from the ICAEW, the AICPA and the Chartered Institute of Taxation reinforces the value of contemporaneous records. Furthermore, Investopedia's overview of section 1031 offers a useful primer on the mechanics. Meanwhile, MoneyHelper explains the UK capital gains framework. Additionally, the HMRC published US treaty texts and the US Treasury treaty library confirm the relief articles.
How TaxYork Can Help
We prepare US and UK returns for high-net-worth Americans across Britain. Our clients include property investors, fund partners, bankers and company owners. Furthermore, we model both sides of a 1031 exchange before you commit, rather than discovering the British charge afterwards.
Specifically, we compute the American and British gains in parallel. Furthermore, we test whether aligning the disposals produces a better outcome. Additionally, we quantify the credit actually available in each year. Additionally, we prepare Form 8824 and the UK Self Assessment pages together so the two filings agree. We also coordinate the analysis with your wider US tax return preparation.
Moreover, our clients typically hold property on both sides of the Atlantic alongside complex remuneration. Therefore, we look at the whole position rather than a single transaction.
Conclusion
A 1031 exchange is a powerful American relief that translates badly across the Atlantic. Above all, section 1031(h) blocks the transatlantic swap most people want, and HMRC refuses to recognise the deferral on the swaps that do qualify. Consequently, a 1031 exchange frequently costs a UK resident more than it saves.
Furthermore, the damage is structural rather than technical. Britain taxes now, America taxes later, and no mechanism bridges the years between. Therefore, a deferral that looks free at completion can crystallise as double taxation a decade afterwards.
Ultimately, the decision turns on residence, timing and the interaction of two computations that never quite match. In summary, model both jurisdictions before you sign, and the 1031 exchange becomes a choice rather than a trap.
Contact Us
Speak to our cross-border team before you commit to any exchange or disposal. To review how a 1031 exchange would affect your US and UK position, book a consultation with our specialists today.
Email hello@taxyork.com or call 020 3488 8606. Alternatively, contact us through our website and we will respond within one working day.
Disclaimer
This article provides general information only and does not constitute tax or legal advice. Tax rules change frequently, and the correct treatment depends entirely on your individual circumstances. Exchange rates used in the illustration are indicative only. Therefore, you should obtain professional advice before acting on anything set out here. TaxYork accepts no liability for any action taken in reliance on this content.