While both the United States and the United Kingdom acknowledge dual citizenship, the United States, as a matter of policy, does not endorse it. However, the U.S. does allow it on a case-by-case basis. The application process – and the likelihood of acceptance – depends on the circumstances. The U.K. does not accept applications for dual citizenship for children. The U.S. generally does not revoke citizenship from holders of another citizenship unless they ask for it to be revoked, or are found to have sworn allegiance to the another country or served in its military.
U.S. Citizens Applying to the U.K.
Determine whether or not you are eligible to apply for U.K. citizenship. You must have lived as a U.K. resident for the past five years, or have lived in the U.K. while married to a U.K. citizen for the past three years. If you are eligible by either circumstance, skip to Step 4.
Determine whether you are eligible to apply because your mother was a British citizen and you were born before 1983. If this is the case, continue to Step 4.
Determine if you are eligible because you were born in the U.K. on or after 1983, and lived in the U.K. until you were 10 years old.
Determine that, in addition to one of the above, you are also of good character and are of sound mind.
Contact the U.K. Border Agency, or download the appropriate form in the References section below to begin the application process.
U.K. Citizens Applying to the U.S.
Determine that you have been a permanent resident of the United States for at least five years. Also determine that you have been in the United States for at least three months before applying for U.S. citizenship, and that you will reside in the United States until your citizenship is granted. If so, skip to Step 4.
Determine that you will be eligible to apply because you are, or have in the past, been a member of the U.S. military. If this is the case, skip to Step 4.
Determine that you are eligible to apply because at least one of your parents is a U.S. citizen.
Determine that in addition to one of the above, you are also able to read, speak and write English. Make sure that you have a good understanding of U.S. history and the U.S. government and that you will be able to pass a test on these subjects.
Make sure that you also are of good moral character.
Contact the United States Citizenship and Immigration Services, or download the appropriate form from the References section below to begin the application process.
If you are uncertain whether or not your situation will be accepted for dual citizenship, contact an immigration lawyer in the country where you are applying.