British expats are scrambling to avoid large tax bills after returning from the Gulf to the UK to flee the conflict.

Accountants are advising families and individuals about HMRC rules after they were forced to leave the Middle East due to Donald Trump’s Iran war.

The tax implications of a return to the UK were said to be “troubling” expats who have flown back to the UK or are making emergency plans to do so.

British expats returning from Dubai and the Middle East, as well as those delaying the move because of the conflict, could face unexpected Capital Gains Tax responsibilities.

Accountancy firm Price Bailey said many could fall foul of Britain’s five‑year temporary non‑residency rule, which is an anti-tax avoidance measure designed to stop people briefly leaving the UK to dispose of assets in low‑tax jurisdictions before quickly returning.

Under the rules, if someone becomes a UK tax resident again within five full tax years, certain capital gains they made while living abroad can be taxed in Britain when they return.

Sandra Jeevan, partner and head of private client and trust at accountants UHY Hacker Young, said: “We are hearing from many families who never intended to return to the UK this year but now have had no choice.

“They could face exposure to UK tax simply because their emergency return alters their UK residence position.”

She added: “When you are trying to move your family to safety, you are not focused on day count rules or technical residence tests.

“While HMRC has updated its guidance to acknowledge that the outbreak of war can qualify as an ‘exceptional circumstance’ for residency purposes, the rules remain highly restrictive and are strictly limited in scope.”

She argued that HMRC had “a very narrow view” of what would qualify and that staying in the UK to be with family after the initial crisis has passed typically would not count as “exceptional”.

She urged: “Given the extraordinary circumstances, HMRC should adopt a pragmatic and sympathetic approach.”

An HMRC spokesman said: “The existing rules already take into account exceptional circumstance, such as people being affected by war, while following the basic principle that those living in the UK should pay tax in the UK.”

Tens of thousands of Britons have already flown back to the UK on commercial or Government charter flights fearing for their safety.

Some of the UAE’s most iconic buildings have been damaged in the conflict, including Fairmont The Palm hotel in the luxurious Palm Jumeirah area and the Burj Al Arab hotel.

Four people were injured after drones fell near Dubai airport earlier this week.

At the start of the war, one person was killed and seven injured when a drone targeting Zayed International Airport in Abu Dhabi was intercepted, leading to “falling debris”.

Several banks have urged their employees to evacuate offices in Qatar and the United Arab Emirates as Iran threatened to launch strikes on financial institutions.

Around 140,000 Britons, mainly in the UAE, had registered with the Foreign Office as it planned exit routes for British citizens, including if needed a major evacuation.

Around 300,000 British citizens were estimated to be living, on holiday or in transit in Gulf countries when the US and Israel started airstrikes on Iran.

Under current rules, an individual must usually remain outside the UK for a whole tax year to ensure foreign income remains outside the UK tax system, UHY Hacker Young stressed.

The accountants added that this meant that being forced to return to Britain because of the Iran war could mean income and gains becoming taxable in the UK.

Ms Jeevan, based in UHY Hacker Young’s London office, added: “Some returning expats may also face UK Capital Gains Tax (CGT) if they resume UK residence before completing the minimum non-residence period required to fall outside the temporary non-residence rules.”

This could apply to business interests, shareholdings or other non-UK assets during their period overseas.