Do I lose Turkish citizenship if I become British? What are dual citizenship and the Mavi Kart (Blue Card)?

Who and where does this apply to?

• This is general information for Turkish citizens living in the UK and for people who have left Turkish citizenship. It was prepared from official pages as of October 2026.
• The UK rules apply across the whole UK. The Turkey side rests on Turkish law.

Details

The UK side

• According to GOV.UK, dual citizenship (also called dual nationality) is allowed in the UK.
• Many countries do not accept it. The other country's rule can be checked with that country's consulate.
• According to GOV.UK, dual citizens cannot get diplomatic help from the British government in their other country of citizenship.

The Turkey side

• Under article 44 of Turkish Citizenship Law no. 5901, people who gain another country's citizenship show their documents. If identity is confirmed, a "multiple citizenship" note is written in their civil record. This article does not require giving up Turkish citizenship.
• Under article 27, Turkish citizenship is lost when the exit document is handed to the person against a signature. From that date the person is treated as a foreigner.
• The London Consulate General's military deferral note says British citizenship must first be entered in the civil record for a deferral application. That condition is for that procedure. This post does not explain how to notify multiple citizenship.

Leaving Turkish citizenship

• Under article 25, a permit to leave requires the person to be an adult, and to have gained another citizenship or have credible signs of gaining it. The person must also not be wanted for a crime or military service, and must have no financial or criminal restriction.
• The exit permit is valid for two years from the decision date (article 26).
• A spouse's citizenship is not affected. Children lose it together with the leaving parent if that parent asks and the other parent consents. If consent is refused, a judge decides. The rule does not apply if the children would become stateless (article 27).

Mavi Kart (Blue Card)

• Under article 28 of Law 5901, the Mavi Kart covers people who were Turkish by birth and lost citizenship with an exit permit, and their descendants up to the third degree (child, grandchild, great-grandchild). The President can widen the degree. Descendants must prove the family link. The card is issued on request.
• According to the Ministry of Foreign Affairs, people outside this scope do not get the card. The card has no expiry date.
• Holders keep the rights of Turkish citizens, with exceptions: no right to vote or stand for election, no duty-free import of a car or household goods, and no military service duty. They cannot hold permanent civil-service posts, but may work in public bodies as workers, temporary or contract staff.
• Abroad, applications go to Turkish missions. A petition, 2 photos and a foreign ID or passport are asked for. The fee is set every year; the 2018 amount on the page may be out of date.

Things to watch

• This post gives no official rule on which document to use to enter Turkey. Ask the consulate and the airline before travelling. For entering the UK, GOV.UK says dual citizens can use a valid UK or Irish passport or a certificate of entitlement.
• According to the London Consulate General, citizens abroad must declare a change of home address within 20 working days. There is an administrative fine for late or false declarations. Amounts are updated every 1 January; the current amounts are in the consulate note.
• For people with a military service duty: the London note says the first deferral needs an appointment and an in-person visit, and postal applications are not accepted. For British citizens, deferral is done "in one go until the end of age 35". Rules can change. Ask the consulate about military service.

What can you do?

• The Turkish Consulate General in London (+44 20 7591 69 00, consulate.london@mfa.gov.tr) can be asked about multiple-citizenship registration, documents, military service and address declaration.
• Questions to ask: Which documents are needed to register multiple citizenship? Which document is used to enter Turkey? What are the current conditions for military service and address declaration?
• For Turkish law, you can ask the consulate or a lawyer in Turkey.
• If you get UK immigration advice, the GOV.UK page Find an immigration adviser says advisers must be registered with the IAA (Immigration Advice Authority) or belong to an approved professional body.
• Rules can change, so the official pages above should be checked again.