What happens to your previous passport?

After taking the Oath of Allegiance you may keep your previous passport, although whether that passport remains legally valid depends on the laws of the country that issued it; some countries automatically revoke passports when a national naturalizes elsewhere, while many others permit dual citizenship and continue to recognize the document. U.S. law does not require surrender or destruction of foreign passports.

The Oath of Allegiance includes language renouncing allegiance and fidelity to foreign sovereigns, but as a matter of U.S. law that renunciation does not automatically extinguish the applicant's foreign citizenship; whether the original citizenship continues is governed by the laws of the other country. The U.S. State Department's policy, expressed in 8 FAM 301.1 and reinforced by Supreme Court decisions in Afroyim v. Rusk (1967) and Vance v. Terrazas (1980), is that dual citizenship is permitted but discouraged, and that U.S. citizens who hold dual citizenship must use a U.S. passport to enter and leave the United States under 22 U.S.C. section 212.

Practical consequences vary widely. Countries such as the United Kingdom, Canada, Australia, France, Italy, Mexico, and the Philippines generally permit dual citizenship, and naturalization in the U.S. does not affect the original citizenship. Countries such as China, India, Japan, and Singapore generally do not permit dual citizenship and may treat U.S. naturalization as automatic loss of original citizenship; their passports may be invalidated.

Applicants should research their country's rules before assuming the previous passport remains usable. State Department guidance on dual nationality is updated periodically; applicants can check current rules at travel.state.gov.