Although the most common way that people become U.S. citizens is by being born in the United States, a few people who were born outside the United States are also considered U.S. citizens by virtue of their parents. If of one or both parent was a U.S. citizen (either native-born or naturalized), the child might, in technical terms, either "acquire" or "derive" U.S. citizenship.
But children who acquire or derive U.S. citizenship will not have a U.S. birth certificate (which is normally the easiest way to prove that one is a U.S. citizen). And they might not receive a document proving their U.S. citizenship from any official source, either. So what can they do if they need such proof? The answer is to apply for a "certificate of citizenship," the process for which we'll discuss here.
Do not confuse the document and application process being described here with the one used by U.S. lawful permanent residents (green card holders) who have completed the required number of years in the U.S. (usually five) and are ready to apply for naturalization. This is a separate path to U.S. citizenship, which requires a completely different USCIS form (N-400, Application for Naturalization) and a different process, which includes an interview and a test of the immigrant's English language abilities and knowledge of U.S. history and government. If successful, such applicants will be issued a Certificate of Naturalization, which again, is different than the certificate described in this article. If an applicant seeking naturalization submits the forms described below, requesting a Certificate of Citizenship instead of naturalization, they will in all likelihood (unless their parents really were U.S. citizens!) be denied.
In some cases, the U.S. citizen parents of someone born outside the United States might have gone to a U.S. consulate in the country where they were staying and obtained confirmation of the child's birth and U.S. citizenship. But not all parents know they can do this.
So, in order to prove their U.S. citizenship, such people can apply to U.S. Citizenship and Immigration Services (USCIS) for a Certificate of Citizenship. If the application is successful, the U.S. government will issue the certificate and number it either N-560 or N-561. Using that certificate (or a photocopy of it), the applicant should have an easy time obtaining a U.S. passport, Social Security number, and more.
To request a Certificate of U.S. Citizenship, you have to fill out either USCIS Form N-600 or N-600K, depending on whether you are filing on your own behalf or on behalf of a child whom you are adopting from another country. You will need to include documents to back up your claim, including your birth certificate, proof of your parent(s)' U.S. citizenship status, and more. For details, see Documents to File With an N-600 Application for U.S. Citizenship.
The application can be filed either online or by mail. Online mailing is slightly cheaper; it's $1,335, as compared to a paper filing fee of $1,385. Some applicants might qualify for a fee waiver (using Form I-912; see Can You Get the Immigration Form Filing Fee Waived?).
For complete instructions, the latest government filing fee, and other filing information, see the Forms page of the USCIS website.
You will be dealing with a government agency that is backlogged in the best of times. Expect a long wait (typically between three and five months). USCIS tracks and reports such information on the Processing Times page of its website. From the Form dropdown menu, choose N-600. Under Form Category, choose "application for recognition of U.S. citizenship." Under Field Office or Service Center, choose the USCIS Field Office that serves your region. Click "Get Processing Time" and look for the recent average.
If you need assistance figuring out whether you qualify for U.S. citizenship based on the citizenship of your parent or parents, or in filing your forms or applying for a certificate of U.S. citizenship, contact an experienced U.S. immigration attorney. The paperwork for U.S. immigration applications can be confusing, while attorneys deal with it regularly and have special software programs to help them fill in all the forms.