Dual Citizenship in 2026: Which Rules Bite Second-Passport HoldersDual Citizenship in 2026: Which Rules Bite Second-Passport Holders

Holding two passports is legal in most places that matter to investors, but legal is not the same as frictionless. Three strands of 2026 news show where the real constraints sit: a UK entry rule that has caught British dual nationals out, a US bill that would end dual citizenship but has not moved, and home-country laws that can end a nationality the moment another is acquired. For anyone weighing a second passport, the order of questions matters more than the ranking of the passport.

The UK rule: citizenship is not the same as proof of it

The UK's electronic travel authorisation (ETA) scheme changed what dual British nationals can show at the check-in desk. According to the House of Commons Library, British dual nationals whose other country is a non-visa national country could once travel on the foreign passport, but can no longer simply do so. The Home Office advises them to use a British passport or a certificate of entitlement to the right of abode.

The same briefing, published on 10 August 2026, notes that a certificate of entitlement costs £589, may take longer than a passport, and is now issued digitally. It cannot be held alongside a British passport. British citizens are not eligible for an ETA, so the foreign passport alone leaves them in a gap.

The Commons Library adds that in late February 2026 the Home Office issued temporary guidance to carriers. They may allow boarding with an expired British passport issued in 1989 or later plus a valid passport from a non-visa national country, if details match. The Home Office calls this a short-term transitional measure, applied at each carrier's discretion. GOV.UK's dual citizenship page sets out the accepted documents.

The lesson reaches beyond the UK. Several countries expect citizens to enter on their own passport, and the US is one of them: the State Department position, as summarised by Ellis, is that US citizens must use a US passport to enter the United States. Anyone adding a nationality, by investment or otherwise, should check what each country requires of its own citizens at the border, including after the second passport is issued.

The US bill: proposed, not law

In the United States, dual citizenship remains legal. Senator Bernie Moreno proposed the Exclusive Citizenship Act on 1 December 2025, according to TheTravel. As described there, it would require US citizens to choose one nationality, with a one-year window for existing dual nationals.

Ellis reports that, as of mid-2026, the bill (S. 3283) remains stalled in the Senate Judiciary Committee, with no hearings, votes or House companion. The same source says nothing in it has taken legal effect. TheTravel cites a forecasting estimate of a 3% chance of enactment; treat such figures as one view rather than a measurement.

For US-linked readers considering a Caribbean or Turkish second passport, the practical reading is narrow. Nothing in force has changed, but a proposal like this is a reminder to check the position of the country that issued your first passport before committing funds, not after.

Home-country law: the question that comes first

The most consequential rule is often the one in your existing passport's country. Ellis lists India, China and Japan among the notable countries that do not allow dual citizenship, and says some countries revoke citizenship automatically when a person naturalises elsewhere. Others, including Canada, Ireland and Mexico, allow both to be held.

Many Multi Mulk readers are from South Asia, China and the Gulf, so this matters. Rules differ by country, and even within a country the treatment of acquiring a foreign passport can depend on how and when it is done. A residence permit or golden visa does not raise the same issue, because it does not confer a second nationality. That is one reason to compare citizenship and residency routes before choosing.

What Türkiye's route looks like on this question

Türkiye is generally described as permitting dual citizenship. Global Citizen Solutions states that Türkiye allows applicants to keep other citizenships. That describes Türkiye's side only. Whether your current country lets you keep your nationality after naturalisation is a separate question, and it should be settled first.

The route itself has been under closer scrutiny this autumn. Reports citing a 4 August Ministry of Interior statement, such as NTL International, say 5,391 people had citizenship cancelled after fake or irregular valuations, with spouses and children covered by the same decision. The same report says citizenship valuations are no longer restricted to GEDAŞ, following a September update to a TKGM circular. We covered the broader enforcement picture in our earlier report.

Multi Mulk advises on Turkish citizenship by investment and offers a free written eligibility review. It also supports clients choosing between programmes through its second passport guidance. Our investor protection work covers due diligence on the property and valuation side.

A short checklist before you pick a passport

The Commons Library briefing flags the fourth point specifically: some dual nationals do not have matching names in their two passports because of naming conventions or transliteration. For families with Arabic, South Asian or Chinese names, that detail can decide whether a boarding exception works.

What to take from this

None of these developments changes the case for or against a second passport. They change the order of the homework. Home-country law comes first, border documentation second, and ranking tables third. Programme rules, passport rules and carrier practice all change, so treat each date above as correct for its source only.

If you are weighing a second nationality against a residence permit, you can speak to an adviser. A decision like this depends on your nationality, family and tax position, and nothing here is legal or tax advice.

Sources

• House of Commons Library — Can a British citizen travel to the UK using a non-British passport? (10 August 2026)
• GOV.UK — Dual citizenship
• Ellis — US Dual Citizenship in 2026: Current Laws, Country List, and Employer Rules
• TheTravel — American Travelers Warned They Could Lose Their U.S. Passport Under New Ban Rule Proposal
• NTL International — Turkish Citizenship by Investment Cancellation 2026
• Global Citizen Solutions — Turkey Citizenship by Investment in 2026

Cover photo: 652234 on Pixabay.