Introduction: Why Incorporation Relief Solves a UK Problem and Creates a US One
Incorporation relief lets a British landlord move an entire property business into a limited company without paying capital gains tax on the day of transfer. Furthermore, the relief has become the standard answer to the mortgage interest restriction that squeezed higher-rate landlords for a decade. Consequently, thousands of substantial portfolios now sit inside companies that once sat in personal names, and incorporation relief is the mechanism that made the move painless.
However, the American owner of a British portfolio faces a completely different outcome from incorporation relief. Britain defers the gain. The United States does not. Therefore, a transaction that costs a British neighbour nothing can cost a US citizen dearly. Specifically, the charge reaches a quarter of the latent gain, in cash, in the year of incorporation. Moreover, no foreign tax credit softens it.
At TaxYork we model both sides before a client signs anything. Moreover, the arithmetic frequently reverses the standard British advice. In our experience, the American who claims incorporation relief usually pays more tax across the life of the portfolio than the American who deliberately declines it.
What Incorporation Relief Actually Does
Incorporation relief sits in section 162 of the Taxation of Chargeable Gains Act 1992. It rolls the gain on the transferred business into the base cost of the shares received. Accordingly, no capital gains tax falls due on the transfer itself. Instead, the gain sits latent inside the shares until the owner sells them.
The mechanics are straightforward. You transfer a business as a going concern to a company, wholly or partly in exchange for shares. All of its assets must go, although cash may stay behind. The HMRC Capital Gains Manual at CG65700 sets out the statutory framework, and helpsheet HS276 provides the computation.
Notably, incorporation relief is generous. A portfolio carrying a £2 million latent gain can move into a company with no immediate British tax at all. Additionally, the company acquires the properties at market value, which resets its own base cost for future disposals.
Why the American Position Is Different
The United States taxes its citizens on worldwide income regardless of where they live. Therefore, an American landlord in London reports the same portfolio to two revenue authorities. Ordinarily the foreign tax credit prevents genuine double taxation, because British tax paid offsets American tax due.
Incorporation relief breaks that mechanism. Specifically, incorporation relief removes the British tax, and a credit system needs foreign tax to credit. Meanwhile, the American charge arrives in full, because Congress wrote a rule that switches off the normal deferral when appreciated property moves offshore.
That rule is section 367 of the Internal Revenue Code. Consequently, the transaction that Britain treats as invisible becomes, in Washington, a fully taxable sale of every property in the portfolio at market value.
The 6 April 2026 Change That Changes the Answer
Britain has just rewritten the procedure, and the rewrite helps Americans considerably. For transfers on or after 6 April 2026, incorporation relief is no longer automatic. Instead, the transferor must claim it in the Self Assessment return for the tax year of the transfer. GOV.UK confirms the point in its published claims guidance.
The same measure repeals section 162A, the old election to disapply the relief. Previously an American who wanted British tax to arise had to elect out affirmatively, within a deadline that many people missed. Now the position inverts. Simply declining to claim produces the same result, without an election and without a trap.
Importantly, most UK commentary treats the change as an administrative burden. For a US citizen it is closer to a rescue.
The UK Rules: Conditions, the Business Test and the New Claim
Britain sets a demanding entry standard for incorporation relief, and HMRC challenges weak claims regularly. Therefore, an American considering the step should understand the conditions of incorporation relief before considering the American overlay at all.
The Statutory Conditions in Section 162
Three conditions govern incorporation relief. First, a person other than a company must transfer a business as a going concern. Second, the transfer must include the whole of the assets of that business, although cash may be excluded. Third, the consideration must consist wholly or partly of shares in the transferee company.
Cherry-picking destroys the claim. Specifically, you cannot incorporate four properties and retain two from the same business. Furthermore, HMRC reads the "all assets" requirement strictly, and the Capital Gains Manual at CG65715 explains how the department approaches marginal cases.
Where part of the consideration takes a form other than shares, incorporation relief is proportionate. Accordingly, the deferred gain equals the total gain multiplied by the share consideration over the total consideration. The balance becomes chargeable immediately.
The Business Test After Ramsay
The pivotal question is whether letting property amounts to a business rather than a passive investment. HMRC v Elizabeth Moyne Ramsay settled the point in 2013. There the Upper Tribunal held that "business" carries a wide meaning and turns on the degree of activity.
Practitioners now treat roughly twenty hours a week of genuine management as the working benchmark. Nevertheless, no statutory threshold exists. Instead, HMRC weighs scale, personal involvement, tenant management, repairs, marketing and record-keeping together.
One property managed entirely by a letting agent will not qualify. In contrast, a substantial portfolio run personally, with maintenance diaries and tenant correspondence to prove it, usually will. Consequently, evidence matters as much as scale, and we advise clients to build the file before the transfer rather than after an enquiry.
Mortgages, Liabilities and the Consideration Trap
Liabilities assumed by the company create the most common technical failure. Where the company takes over mortgages, HMRC can treat the debt as consideration other than shares, which reduces incorporation relief proportionately. Extra-statutory concession D32 mitigates that outcome. However, the liabilities must be genuine business debts taken over with the business.
Refinancing shortly before incorporation attracts particular scrutiny. Moreover, drawing cash out of the portfolio and then incorporating can convert a clean transaction into a partly chargeable one. Therefore, sequencing matters enormously.
For an American, the liability point carries an additional sting that no British adviser will mention. American tax law contains its own rule on assumed liabilities, and the two interact badly. We return to that below.
The Claim Requirement From 6 April 2026
From 6 April 2026, incorporation relief requires a claim on the Self Assessment return for the tax year of the transfer. Claimants must supply brief details of the transaction, the supporting computations and the type of business transferred. Additionally, HMRC may require further information.
The measure applies to individuals, partners and trustees. Furthermore, the Exchequer expects it to raise around £110 million in 2029-30, which tells you how many claims HMRC expects to reject. The ICAEW guidance on preparing for 2026-27 covers the wider package of changes taking effect on the same date.
Above all, the claim is now a decision rather than a default. For a US citizen that decision is the single most valuable one in the whole transaction.
Section 367: The US Charge That Ignores the British Deferral
American law would ordinarily treat the transfer of property to a company you control as a non-event. Section 367 removes that treatment whenever the company is foreign. Consequently, incorporation relief and the American rules pull in opposite directions on identical facts. Section 367 is the single provision that turns incorporation relief from a saving into a cost.
Why Section 351 Would Have Worked
Section 351 of the Internal Revenue Code normally prevents gain on a transfer of property to a corporation for stock. However, the transferors must control the corporation immediately afterwards. Control means eighty per cent of voting power and eighty per cent of every other class of shares.
A landlord who moves a portfolio into a wholly owned company satisfies that test comfortably. Therefore, if the company were American, the transaction would carry no US tax, and the two regimes would align neatly.
The company, however, is British. Accordingly, section 351 never gets the chance to apply.
What Section 367(a)(1) Does Instead
Section 367 of the Internal Revenue Code disregards the corporate status of a foreign company. That rule applies when measuring the gain a US person recognises on an outbound transfer. In plain terms, the non-recognition rule switches off. Consequently, the transferor recognises the full built-in gain on every asset moved.
The measure is market value less adjusted basis, asset by asset. Furthermore, losses do not offset gains, because section 367 recognises gain only. Therefore, a portfolio containing one loss-making flat and nine profitable houses produces tax on the nine with no relief for the one.
This is the point that British advisers consistently miss. Incorporation relief protects the client from HMRC, and section 367 hands the identical gain to the IRS in the same tax year. In short, incorporation relief defers one bill and accelerates another.
The Repeal of the Active Trade or Business Exception
Older American guidance describes an exception for property transferred for use in an active trade or business outside the United States. That exception no longer exists. Specifically, Congress repealed section 367(a)(3) for transfers after 31 December 2017 as part of the 2017 tax reform.
Consequently, foreign operational use no longer protects anything. A genuine, actively managed British property business receives exactly the same treatment as a passive holding. Moreover, the parallel concession for foreign goodwill and going concern value disappeared at the same time. Accordingly, section 367(d) now reaches intangibles that once sat outside the net.
Any adviser still citing the active trade or business exception is working from pre-2018 material. Therefore, treat such advice with considerable caution.
Assumed Liabilities, Depreciation Recapture and the NIIT
Three further American rules compound the charge. First, section 357(c) treats liabilities assumed by the company in excess of the transferor's aggregate adjusted basis as gain. A heavily mortgaged portfolio with a low American basis can therefore produce gain even before section 367 bites.
Second, American basis in a British rental property is lower than owners expect, because US law requires depreciation over forty years on the straight-line alternative depreciation system. Accordingly, decades of mandatory depreciation reduce basis and enlarge the gain. Unrecaptured depreciation then attracts tax at up to twenty-five per cent, and IRS Publication 544 explains the ordering.
Third, the net investment income tax adds 3.8 per cent to gain on property held outside an active American trade or business. Critically, no foreign tax credit ever reduces that charge.
Form 926 and the Reporting That Follows Incorporation Relief
The American charge arrives with a reporting obligation that carries its own penalty regime. Furthermore, the penalty is proportionate to the value transferred, which makes it dangerous on a large portfolio.
Who Must File Form 926
A US person who transfers property to a foreign corporation in a section 351 exchange files Form 926 with the return for the year of transfer. The IRS guidance on the Form 926 filing requirement sets out the scope, and the instructions to Form 926 prescribe the content.
The form demands the fair market value, the adjusted basis and the gain recognised for each category of property transferred. Additionally, it requires details of the transferee company and the transferor's resulting ownership percentage. Therefore, a proper valuation file is not optional.
Notably, the obligation applies even where the transfer produces no gain. Consequently, an American who incorporates a portfolio standing at a loss still files.
The Section 6038B Penalty
Failure to report attracts a penalty of ten per cent of the fair market value of the property transferred. The penalty is capped at $100,000 unless the failure resulted from intentional disregard, in which case no cap applies. Regulation 1.6038B-1 contains the detail, together with the reasonable cause defence.
Ten per cent of a £4 million portfolio reaches the cap immediately. Therefore, the practical position is that any unreported incorporation of a substantial portfolio costs $100,000 unless reasonable cause applies. Furthermore, reasonable cause requires evidence, not assertion.
The Extended Assessment Period
Non-filing carries a second consequence that outlasts the penalty. Specifically, the assessment period for tax on the transfer stays open until three years after the required information is supplied. Consequently, an unfiled Form 926 keeps the year permanently exposed.
Americans who discover the problem years later can usually fix it. Moreover, where returns were missed entirely, the IRS Streamlined Filing Compliance Procedures may provide the route back. Nevertheless, the sooner the disclosure, the better the outcome.
The Foreign Tax Credit Arithmetic That Decides the Question
Everything now turns on one comparison. Does the American claim incorporation relief, or decline it? The answer follows from the credit arithmetic of incorporation relief, and the arithmetic is decisive.
Why Claiming the Relief Strands the Credit
Assume a portfolio with a £2 million latent gain. If the owner claims incorporation relief, British tax on the transfer is nil, because incorporation relief rolls the whole gain into the shares. Meanwhile, section 367 produces an American gain on the full amount.
The American tax runs at up to twenty per cent on long-term capital gain, plus 3.8 per cent net investment income tax, giving 23.8 per cent. No British tax exists to credit. Therefore, the owner writes a cheque to the IRS for roughly 23.8 per cent of the gain, in dollars, in the year of incorporation.
Worse, the British gain has not disappeared. Instead, it now sits inside the shares. When those shares are eventually sold, Britain taxes the rolled-over gain at up to twenty-four per cent under the current capital gains tax rates. By then the American basis in the shares already reflects the gain recognised under section 367, so almost no American income exists to absorb the credit. Consequently, that later British tax strands.
Why Declining the Relief Usually Wins
Now assume the owner declines to claim. Britain charges capital gains tax at twenty-four per cent on the £2 million. Furthermore, gain on land and buildings is sourced where the property sits, so the gain is foreign source for American purposes and the British tax is creditable.
The American regular tax of twenty per cent falls away entirely, absorbed by the British credit. Only the 3.8 per cent net investment income tax remains payable. Therefore, the total cash cost is roughly 27.8 per cent, and the excess credit carries forward.
Compare the two paths across the life of the holding. Claiming costs 23.8 per cent now plus up to twenty-four per cent later, much of it unrelieved. Declining costs 27.8 per cent once, and settles the British gain permanently. Accordingly, the four-point premium buys a permanent solution, and IRS Publication 514 governs how the credit and any carryforward operate.
The Third Path: Electing Away From Section 367
A private limited company is not on the American list of entities that must be treated as corporations. Only a public limited company appears there. Consequently, a UK limited company may elect its own classification on Form 8832.
Where a single owner elects to treat the company as disregarded, American law sees no corporate transfer at all. Therefore, section 367 never engages, no gain arises, and no Form 926 falls due. Meanwhile, Britain still treats the company as a company, so incorporation relief and the corporate tax regime operate normally.
The trade-offs are real. Specifically, British corporation tax paid by a disregarded entity flows to the American owner for credit purposes. That usually helps. However, foreign currency rules under section 987 then apply to the branch. Moreover, the election must be in place before the transfer. Therefore, timing governs whether this path is available at all.
Stamp Duty, Corporation Tax and Life Inside the Company
Incorporation relief addresses one tax only. Consequently, three further charges deserve attention before anyone relies on incorporation relief and signs a transfer.
Stamp Duty Land Tax on the Transfer
The company acquires the properties at market value, and stamp duty land tax follows that value rather than any price actually paid. Furthermore, connected-party rules prevent a nominal transfer price from reducing the charge.
Companies buying residential property above £500,000 face a flat seventeen per cent rate, as GOV.UK explains for corporate bodies. However, a genuine property rental business escapes that rate. Specifically, SDLTM09555 grants relief for a qualifying property rental business. The acquisition must be exclusively for exploitation as a source of rents, and the business must run commercially with a view to profit.
Relief from the seventeen per cent rate leaves the higher rates for additional dwellings, which add five percentage points. Additionally, a non-resident purchaser adds a further two. Where the landlords genuinely operate in partnership, Schedule 15 of the Finance Act 2003 can reduce the charge substantially. Notably, stamp duty land tax is a transaction tax. Therefore, it earns no American credit and instead capitalises into basis.
Corporation Tax and the Small Profits Trap
The company pays corporation tax on rental profits at the rates published on GOV.UK. However, a close investment holding company cannot access the small profits rate at all. Consequently, many single-owner property companies pay the main rate on the first pound of profit.
The active rents exception is narrower than most owners assume. Therefore, the anticipated saving against personal higher-rate tax often shrinks once the American overlay is added.
The Company Becomes a Controlled Foreign Corporation
An American who owns a British company outright creates a controlled foreign corporation on day one. Accordingly, Form 5471 becomes an annual obligation. Furthermore, non-filing costs $10,000 per company per year.
Rental income is generally foreign personal holding company income, which the American owner reports currently. Furthermore, the exception for active rents demands substantial in-house management that few property companies satisfy. Therefore, incorporation frequently converts a simple Schedule E filing into a full international compliance package. Our US tax return preparation for expats team sees the consequences every filing season.
Common Mistakes Americans Make With Incorporation Relief
Certain errors recur in almost every file we review. Furthermore, each one is avoidable with modelling done before the transfer rather than after it.
Treating British Advice as Complete
The most expensive mistake is accepting a British incorporation relief proposal without an American computation attached. British accountants rarely hold US qualifications, and nothing in the section 162 analysis prompts them to consider section 367. Consequently, the client sees a projection showing nil tax and signs.
We have reviewed incorporation relief proposals running to twenty pages without one mention of the IRS. Each carried six-figure American consequences. Therefore, insist that both computations sit in the same document before you decide.
Assuming the Deferral Travels
Owners frequently assume that because Britain defers the gain, America follows. It does not. Specifically, incorporation relief is a domestic British rule with no treaty counterpart, and the United States-United Kingdom treaty contains nothing that extends it.
Additionally, the saving clause preserves the American right to tax its citizens as though the treaty did not exist. Consequently, no treaty argument rescues a claim for incorporation relief from section 367.
Missing the Basis Difference
American basis and British base cost diverge sharply on rental property. Specifically, the United States mandates depreciation over forty years, while Britain grants none on the building. Accordingly, the American gain always exceeds the British gain, often by twenty per cent or more.
Owners who model the American cost using their British figures therefore understate it materially. Moreover, that understatement grows with every year of ownership.
Leaving the Classification Election Too Late
Form 8832 can remove section 367 from the transaction entirely, but only if the election takes effect before the transfer. An election filed after completion arrives too late, and incorporation relief then sits alongside an unrelieved American charge. Consequently, the classification decision belongs at the planning stage, not the compliance stage.
Case Study: A £4.2 Million London Portfolio
Numbers make the choice concrete. The following case reflects a composite of engagements we have handled, with figures adjusted for confidentiality.
The Facts
A dual US-UK national in Islington owned nine let properties worth £4.2 million. She had acquired them between 2004 and 2016 for £1.9 million. Consequently, the British latent gain stood at £2.3 million. Mortgages totalled £1.6 million.
Her American adjusted basis was lower still, at £1.55 million. Twenty years of mandatory forty-year depreciation had eroded it. She managed the portfolio personally, roughly twenty-five hours each week, and her records comfortably satisfied the business test.
Her British adviser proposed incorporation with a claim for incorporation relief. That projection showed nil capital gains tax and long-term savings on mortgage interest. Furthermore, the proposal contained no American analysis whatsoever.
What Claiming the Relief Would Have Cost
Section 367 would have produced an American gain of approximately £2.65 million, measured against her lower American basis. At an exchange rate of 1.27, that gain converted to about $3.37 million.
Long-term capital gains tax at twenty per cent came to $674,000. Unrecaptured depreciation added a further charge at twenty-five per cent on the depreciation element. The net investment income tax added $128,000. Consequently, the immediate American bill approached $850,000, payable in cash, against nil British tax and no credit at all.
Additionally, the £2.3 million British gain would have survived inside her shares. Therefore, a future disposal carried up to £552,000 of British tax with almost no American income left to absorb the credit.
What We Did Instead
We recommended incorporating without claiming incorporation relief at all. Britain charged capital gains tax at twenty-four per cent on £2.3 million, producing £552,000. Furthermore, that tax was creditable, because gain on British land is foreign source.
The credit extinguished her American regular tax entirely and left surplus credit to carry forward. Only the net investment income tax of $128,000 remained. Consequently, her total cost fell from roughly $850,000 plus a stranded future British charge to £552,000 plus $128,000. Furthermore, the British gain was settled permanently, and the company held a market-value base cost.
We also filed Form 926 and put the Form 5471 programme in place before the first accounting period ended. Moreover, we modelled the Form 8832 alternative, which she declined for commercial reasons connected to her lender.
How TaxYork Can Help
Cross-border property incorporation demands both sets of rules applied to the same facts at the same time. Furthermore, the decision is effectively irreversible once the transfer completes.
Modelling Both Sides Before You Transfer
We prepare a side-by-side computation for every path. Specifically, it covers the British gain after incorporation relief, the American section 367 gain, depreciation recapture, the net investment income tax and the credit position across several years. Consequently, clients see the real cost of each path rather than the British half of it.
Getting the Claim Decision Right
Since 6 April 2026 the claim is a live choice, and the choice belongs on the Self Assessment return. Therefore, we coordinate the British return and the American return so that the two positions match. Additionally, our tax treaty optimisation work identifies where relief remains available on later disposals.
Handling the Reporting That Follows
Incorporation relief does nothing to reduce the reporting that follows, and incorporation triggers Form 926, an annual Form 5471 and often new account reporting. Accordingly, our FBAR and FATCA compliance team reviews the account position as soon as the company opens its first bank facility. In our experience, the reporting is where penalties actually arise, long after the tax has been settled.
Conclusion
Incorporation relief remains an excellent British answer to a British problem. However, incorporation relief is a poor answer for an American, because section 367 taxes the identical gain in the same year and leaves nothing to credit. Consequently, the standard advice that works for a British landlord can cost a US citizen a quarter of the portfolio gain in cash.
The 6 April 2026 reform improves the position materially. Since incorporation relief now requires a claim, the American can simply decline it, accept a creditable British charge and settle the gain permanently. Furthermore, a Form 8832 election made in good time can remove section 367 from the picture altogether.
Above all, model the numbers before the transfer, not after. In summary, the cheapest British transaction is rarely the cheapest transaction for an American.
Contact Us
Our specialists prepare US and UK returns for high-net-worth clients on both sides of the Atlantic. Additionally, we handle property incorporations from the modelling stage through to the first Form 5471. Therefore, speak to us before you sign a transfer, not afterwards.
Email hello@taxyork.com or call 020 3488 8606 to book a consultation. Additionally, you can review our full range of cross-border tax services online. Further background on British practice is available from HMRC, the Chartered Institute of Taxation and the American Institute of CPAs.
Disclaimer
This article provides general information on incorporation relief and United States tax rules as at September 2026. It does not constitute tax advice and no reader should act on it without professional guidance applied to their own circumstances. Tax law changes frequently, and cross-border outcomes depend heavily on individual facts, residence, domicile and citizenship. TaxYork accepts no liability for any action taken in reliance on this article.