The U.S. Citizenship and Immigration Services Form N-400, Application for Naturalization, is the form people use when applying for U.S. citizenship, reports USCIS. Applicants must fill out the form accurately and completely, sign it, and mail it along with a filing fee to the appropriate address.
On Form N-400, applicants first indicate their basis for citizenship eligibility, explains Nolo. They then provide personal information such as name, Social Security number, birth date and date they became permanent residents of the United States by obtaining a green card. The form asks applicants to provide contact information, current address, details about their parents and children, their employment history, and any schools they attended. They must also give details about their marital history, criminal history and time spent outside the United States. A number of yes/no questions inquire about any past situations that might jeopardize the claim for citizenship. This can include time spent in a mental institution, membership in questionable organizations, asylum or refugee status, and loyalty to the United States.
Applicants should be honest while filling in Form N-400, as they could lose their citizenship if they are caught lying, advises Nolo. They should be careful that the information provided matches details on documents turned in previously. If they need more space than the form provides, applications should attach extra pages.