Passports are issued by the U.S. Department of State only to United States citizens. A current passport, a copy of a current passport including all pages or an undamaged, expired passport will serve as evidence. Passports require proof of citizenship before being issued, so it's an efficient way to prove your American citizenship in other situations.
A birth certificate issued by your city, county or state will prove citizenship. As of April 1, 2011, all birth certificates must include the full names of both parents. Birth certificates that do not contain this information will not be considered a form of proof of citizenship. Acceptable birth certificates must also contain the full name, date of birth, place of birth, the seal of issuing authority, a registrar's signature and the date the certificate was filed with the registrar.
A Certification of Citizenship is one of the primary documents accepted as proof of citizenship. These certificates are issued to people born outside of the U.S. who derived or acquired citizenship through their parents, such as biological children born abroad or children adopted from a foreign country and brought to live in the U.S. These are usually issued by the USCIS, and can be obtained by filling out an application (form N-600) and paying a filing fee.
A Consular Report of Birth Abroad or Certification of Birth are issued when someone is born outside of the U.S. yet is a citizen through his parents. These need to be filed as soon as possible after the birth of the child because the report serves as an official record of the child's claim to U.S. citizenship. The report can be made at the nearest U.S. embassy or consulate, and the original is given to the parents. Copies or changes can be requested through the Department of State.
A Naturalization Certificate is issued to someone who became a U.S. citizen after turning 18 through the naturalization process. In most cases, people who wish to become naturalized citizens must first be a permanent resident, or green card holder, before applying. This certificate is issued by the USCIS using form N-400. Naturalized citizens should not apply for the Certificate of Citizenship, though the process is similar.
If primary proof of citizenship is impossible to obtain, acceptable secondary forms of citizenship exist. These ar varied, and often require additional evidence. Examples include early public records, like a baptismal certificate, hospital birth certificate and a census record, but it is important to note that early public records cannot be accepted alone and must be accompanied by a birth record or a Letter of No Record. Visit the U.S. Department of State website (travel.state.gov) for up-to-date information.
