Dual National US UK: Business Investment Relief After 2025

For a Dual national US UK investor, business investment relief did not end with the remittance basis. Legacy investments stay protected only until a potentially chargeable event occurs, after which you have 45 days, or 90 plus 45, to move the sum invested offshore or reinvest it. Miss the window and the original foreign income is taxed as remitted.

That is the short answer. The longer one matters because the rules now sit inside a closing window: the relief itself is switched off for new investments and reinvestments from 6 April 2028, and the US return sees none of it. At Jungle Tax we prepare both the UK Self Assessment return and the US Form 1040 for clients in exactly this position, and the same pattern recurs: the investment was made carefully, the claim was made correctly, and then nobody watched the conditions afterwards. This guide is a compliance and reporting reference for that second phase. It does not cover whether to invest, restructure or exit.

What is business investment relief, and who still holds it?

Business investment relief (BIR) was introduced on 6 April 2012. It allowed a remittance basis user to bring foreign income and gains to the UK without a tax charge, provided the money was invested in a qualifying private company within 45 days and a claim was made on the Self Assessment return. The relief treats the money as not remitted. It does not exempt it. The foreign income and gains remain what they always were, sitting inside the shares or the loan, waiting for the conditions to fail.

Citizenship was never the test. The remittance basis turned on domicile, so a US citizen who also holds a British passport could use it while they remained non-UK domiciled under general law and not yet deemed domiciled. Many long-resident Americans did exactly that, then invested offshore earnings or portfolio gains into a UK trading company they founded, backed or worked in.

Did the relief end on 6 April 2025?

Not quite, and the popular summary is wrong in both directions. Three separate things are true:

• Foreign income and gains arising on or after 6 April 2025 cannot be sheltered by BIR. There is no remittance basis for them, so there is nothing for the relief to switch off. They are taxed as they arise unless another regime applies.
• Foreign income and gains from earlier remittance basis years can still be used to make a new qualifying investment, with a claim, until 5 April 2028. HMRC's manual confirms that a former remittance basis user does not need to be on the remittance basis in the year of investment.
• Investments already made keep their protection for as long as the conditions continue to be met, including after 6 April 2028. The protection has no expiry date. It has triggers.

HMRC's published business investment relief guidance sets out the framework, and the detailed mechanics sit in the Residence, Domicile and Remittance Basis Manual from RDRM34300 onward.

What are the potentially chargeable events?

The legislation names four events. HMRC's manual lists them at RDRM34390. Each one starts a clock, and none of them is a tax charge by itself. The charge arises only if the required steps are not taken in time.

1. Disposal of all or part of the holding

Selling shares, having them redeemed or bought back, receiving repayment of a loan, or transferring the holding to someone else all count. A transfer to a spouse is treated as a disposal for this purpose even though it may be neutral for capital gains tax. Partial repayments of a founder loan are part disposals, and each one starts its own 45-day period.

2. The company ceasing to qualify

The target must remain an eligible trading company, an eligible stakeholder company, an eligible holding company or an eligible hybrid company, and it must remain a private limited company. The practical risks are a listing on a recognised stock exchange, a drift from trading into passive investment activity so that trading is no longer substantially all of what the company does, and a group reorganisation that leaves the investor holding shares in an entity that fails the test.

3. Extraction of value

The rule is breached when you or a connected person receive value from the company, or from a company linked to it, that is attributable to the investment and is not provided on ordinary commercial terms and subject to UK tax. A market salary for real work, taxed through payroll, is not a breach. Dividends paid on commercial terms and taxed in the ordinary way are not a breach. A rent-free flat, an interest-free director's loan, or personal costs met by the company are the classic failures. This is the event most often discovered late, usually when the company's own accounts are being finalised.

4. The start-up rule

A company that was not yet trading when you invested must begin to trade within a fixed period. For investments made before 6 April 2017 that period is two years. For investments made on or after 6 April 2017 it is five years. The same rule is breached if the company becomes non-operational after the start-up period has run. Readers often conflate the two-year start-up rule with the two-year grace period described below. They are different things.

Is insolvency a chargeable event?

Where the company enters administration or receivership, or is wound up or dissolved, for genuine commercial reasons, that is not itself a potentially chargeable event. If you receive anything of value in the insolvency process, however, the mitigation rules apply to what you receive.

How long do you have? The 45-day and 90-day grace periods

The grace periods are set out at RDRM34480. They are short, they run in calendar days, and they start from different moments depending on the event.

Two points are routinely missed. First, where the event is anything other than a disposal, the whole holding must be disposed of, not just a slice proportionate to the breach. A modest benefit received by a family member can therefore force a sale of the entire stake. Second, the "ought reasonably to have been aware" wording means the 90 days can start before you actually know. An investor who does not read management accounts is not protected by that.

What counts as an appropriate mitigation step?

There are two permitted steps, and they can be combined (RDRM34440):

• take the disposal proceeds offshore, so that they are no longer available to be used or enjoyed in the UK by you or a connected person; or
• reinvest them in another qualifying investment, which is itself a new BIR claim.

How much has to leave the UK?

Not the whole sale price. The amount that must be dealt with is capped at the sum originally invested, less anything already taken offshore, reinvested or previously treated as remitted. HMRC's own illustration is an investor who put in £1 million and later receives £1.2 million: £1 million must be taken offshore or reinvested, and the £200,000 excess may stay in the UK. That excess is a gain on a UK asset and is taxed in the ordinary way. It is not foreign income or gains and never was.

What changes on 6 April 2028?

Reinvestment disappears as a mitigation step. From that date it is no longer possible to make a qualifying investment or claim BIR, so the only way to cure a potentially chargeable event is to take the money offshore. HMRC's manual states this applies even where the grace period began before that date and runs past it. The manual also notes that a share-for-share exchange on a corporate restructuring after that date will be a potentially chargeable event with no reinvestment route available. For anyone holding a legacy stake in a company likely to be reorganised or acquired for paper consideration, that is the single most important date in this guide.

What does a breach mean on the Self Assessment return?

If the mitigation steps are not completed in time, the foreign income and gains used to make the investment are treated as remitted to the UK immediately after the grace period ends. The consequences follow from that:

• The tax year is the year the grace period ends, not the year of the event. A sale in late February with proceeds left onshore produces a remittance in the following tax year once the 45 days run past 5 April.
• The character of the money is the character it had when it was earned. Remitted foreign employment income, interest and dividends from remittance basis years are taxed at the ordinary income rates, up to 45 percent, and foreign dividends do not get the lower dividend rates on this route. Remitted foreign chargeable gains are taxed at capital gains tax rates.
• The amount is the sum invested, to the extent not dealt with, not the value of the holding at the date of breach. A failed company can still generate a full remittance charge.
• Where the original funds came from a mixed account, the statutory ordering rules decide which income and gains the investment is treated as containing. The analysis done at the time of the claim needs to be on file, because it will be needed again.
• The remittance is reported on the return for that year, due by 31 January following the end of the tax year, with tax payable on the same date.

A breach discovered years later is a different exercise. It means an earlier return omitted a remittance, which requires an amendment where the window is open or a disclosure to HMRC where it is not, with interest and a penalty that depends on behaviour. Our UK return preparation work in this area usually begins with reconstructing the timeline: date of investment, date of event, date of awareness, date the proceeds became available, and where the money sat on day 46.

How does the temporary repatriation facility interact with a legacy investment?

We cover the facility in depth elsewhere, so this section deals only with the overlap. Foreign income and gains locked inside a BIR investment can be designated under the temporary repatriation facility without being taken out of the company. HMRC confirms this at RDRM74710.

The effect is specific. Once an amount is designated and the charge is paid, no further UK tax arises on a later disposal or breach in respect of that amount, and the mitigation steps are no longer needed for it. Designation can be partial: some of the sum invested, or one investment and not another. The charge is 12 percent for amounts designated in the 2025-26 or 2026-27 return and 15 percent for 2027-28, after which the facility closes.

From a reporting point of view, that produces three categories of legacy holding, and the return has to distinguish them:

• Designated in full: the clock no longer matters for UK purposes.
• Designated in part: the undesignated balance remains exposed to all four events and all the grace periods.
• Not designated: fully exposed, and after 5 April 2028 there is no reduced rate and no reinvestment route.

Money taken offshore as a mitigation step is in the same position as any other pre-April 2025 foreign income and gains. Taking it offshore cures the BIR event. It does not cleanse the money, which remains taxable if it is later brought to the UK undesignated.

The US side: why no foreign tax credit matches a UK remittance charge

This is the part that UK-only commentary leaves out, and it is where dual filers are most often surprised.

The United States taxes its citizens on worldwide income in the year it arises. The remittance basis is a UK concept with no US counterpart. So the salary, interest, dividends or gains that funded the investment were reported on a Form 1040 in the year they were earned, possibly a decade ago, and US tax was paid then, usually with little or no UK tax to credit against it because the UK had not taxed the income.

When a breach produces a UK remittance charge in, say, 2026-27, the UK is taxing that same income for the first time. The US is not taxing it at all in that year, because it already did. The foreign tax credit is claimed on Form 1116 in the year the foreign tax is paid or accrued, and it is limited to the US tax on foreign-source income in the same category for that year. The UK tax arrives in a year with no matching US income. Unused credits can generally be carried back one year and forward ten, which rarely reaches the year the income was originally taxed. Where the US return for that original year is still within the refund limitation period, and for foreign tax credit claims that period is longer than the ordinary one, the position should be examined. Often it is not available, and the result is the same income taxed once by each country with no relief in either direction.

Is the temporary repatriation facility charge creditable in the US?

There is no IRS guidance addressing it directly. The IRS did rule in 2011 that the old annual remittance basis charge was a creditable income tax, but that ruling concerned a different levy. The position for the facility charge should be treated as unsettled, and in any event it faces the same timing problem: a charge paid now in respect of income the US taxed years ago.

What must be reported to the IRS while the investment is held?

The UK company is a foreign corporation for US purposes, and the holding has its own reporting life irrespective of BIR:

• Form 8938 for shares in, or loans to, a foreign company held directly, where total specified foreign financial assets exceed the threshold. For a single filer living abroad that is $200,000 at year end or $300,000 at any time in the year; the figures double for a joint return.
• Form 5471 where the holding reaches 10 percent or the company is controlled by US shareholders. Each missed form carries a $10,000 penalty, and a founder who has held 100 percent of a UK company for years without filing has a serious but curable problem.
• FBAR for the offshore account that receives the proceeds, and for any company account over which you have signature authority, where aggregate foreign balances exceed $10,000. Our FBAR penalty calculator shows the exposure.
• Schedule D and Form 8949 for the disposal, with basis and proceeds each translated at the exchange rate on its own date.

Where those forms were missed and the failure was not wilful, the route back is usually the IRS streamlined filing procedures. In our experience a BIR exit is frequently the moment the gap comes to light, because the sale forces someone to look at the holding from the US side for the first time.

A worked timeline: one disposal, two returns

Consider a US citizen with British citizenship who was a remittance basis user until 5 April 2025. In 2019 she brought £800,000 of foreign investment income to the UK and subscribed for shares in a UK trading company within 45 days, claiming BIR. She has not designated any of it under the temporary repatriation facility.

1. 10 November 2026: she sells the shares for £1.1 million. Completion funds reach her UK account the same day. The 45-day clock starts.
2. By 25 December 2026: £800,000 must be in an offshore account or in a new qualifying investment. The remaining £300,000 can stay in the UK.
3. UK 2026-27 return: a capital gain of £300,000 on a UK asset. If the £800,000 left in time, no remittance is reported. If it did not, £800,000 of foreign income is treated as remitted in 2026-27 and taxed at income rates.
4. US 2026 return: a capital gain computed in dollars using the 2019 and 2026 exchange rates, with a credit for the UK tax on the gain. The £800,000 does not appear as income. It was reported in the years it was earned.
5. If the breach occurred: the UK tax on the £800,000 is foreign tax paid in a year with no matching US income. The credit is carried, and may never be used.
6. The offshore account: reported on the FBAR and Form 8938 for 2026, and still holding pre-April 2025 foreign income for UK purposes.

The figures are illustrative. The sequence is not. Christmas week is a poor time to discover that a sterling transfer of that size takes several days to clear compliance checks at the receiving bank.

Records a legacy BIR holder should have on file

• The original BIR claim and the Self Assessment return on which it was made.
• Bank evidence of the date funds arrived in the UK and the date of investment, showing the 45 days were met.
• The analysis of what the invested funds contained, by year and by type of income or gain.
• Annual confirmation that the company remains a qualifying private trading company or group.
• A record of everything you and connected persons receive from the company, with evidence of commercial terms and UK tax paid.
• For companies that had not started trading at investment, the date trading began.
• Any temporary repatriation facility designation, by amount and by investment.
• US basis records in dollars at the historic rate, and the Forms 8938 and 5471 filed for each year of ownership.

For clients with holdings of this kind, our high net worth and US-UK tax accountants pages explain how both returns are prepared together, and US tax services covers the federal filings in detail.

Key points

• Legacy BIR investments remain protected after April 2025 and after April 2028, but only while the conditions are met.
• Four events start a clock: disposal, loss of qualifying status, extraction of value, and breach of the start-up rule.
• The windows are 45 days after a disposal, 90 plus 45 days for most other events, and two years for the five-year start-up rule.
• Only the sum invested needs to be taken offshore or reinvested. Reinvestment stops being possible on 6 April 2028.
• A breach is reported as a remittance in the year the grace period ends, taxed according to the original character of the money.
• The US taxed that income when it was earned, so a later UK remittance charge has no matching US tax to credit against.
• The holding carries its own US reporting each year, separate from anything on the UK return.

If you hold a legacy business investment relief stake and want both returns prepared by one team that understands how the UK clock and the US forms fit together, or if you suspect a grace period has already been missed or a US form was never filed, contact our cross-border team for a confidential consultation. We will review the timeline, confirm what each return needs to show, and bring any missed filings up to date.