Consider a person in the US which has no papers but claiming he has a US citizenship. How the authorities verify that he is indeed a citizen rather than an illegal immigrant, given that neither passport nor residency registration is mandatory?

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    This question appears to be off-topic because it is about national citizenship law (how to prove citizenship). Nov 25, 2014 at 14:30
  • While its an interesting answer, the asker's intention seems nothing related to travel
    – skv
    Nov 25, 2014 at 15:04
  • Perhaps there are "special" travel requirements involved in their vocation. Nov 25, 2014 at 15:08
  • @CGCampbell: I'm pretty sure that's just to speed up the common case and there are fallback methods. Nov 25, 2014 at 15:10
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    Consider a person in any country trying to obtain a passport. How does that person prove he or she is eligible for one? In any case, for most Americans, the only time your citizenship would be relevant on a semi-regular basis are jury duty and elections. Most people do not want to serve on juries, so that is a non-issue. For elections, as recent as 8 years ago, a majority of states required no identification whatsoever, and the introduction of that requirement is highly controversial.
    – choster
    Nov 25, 2014 at 15:40

2 Answers 2


Ultimately birth records, represented by a birth certificate.

This is just an official document that proves a certain person is a US citizen. The question conflates this with how a person proves that they are who they claim they are.

For that purpose, there are all kinds of databases (which do include photos) kept by various agencies. If you try using someone else's identity (aka identiy theft), you'll eventually run into a situation where someone notices that the photos don't match. Or, if you look similar enough, someone will notice that two people are using the same identity. You can't use a dead person's identity either because deaths are also recorded in these databases.

  • They have no photo. Suppose one claims he is John Doe born in 1975 in certain place (which birth is recorded).
    – Anixx
    Nov 25, 2014 at 14:46
  • @Anixx: see updated answer. Nov 25, 2014 at 15:08
  • @Anixx This is really the correct answer. Don't confuse proof of identity with proof of citizenship. In the US, the primary proof of citizenship is a birth certificate (for citizens born here). If I am required to prove my citizenship, I give my birth cert and I would be good to go. If they were to then claim I was not that person, I would need to prove my identity, a separate event, with a photo id.
    – CGCampbell
    Nov 26, 2014 at 15:17

For Americans born in the US, a birth certificate (typically issued by the U.S. State where the person was born, or the State Department if the person was born abroad), possibly certified, usually suffices (see below for limitations when applying for a passport). For others, certificate of Citizenship or Naturalization Certificate (or a U.S. passport). Reference here.

There are also secondary proofs possible. See here. Also, the documents required to prove citizenship for a U.S. passport application may be of interest.

  • Birth certificate does not have a photo. What if a person uses another person's birth certificate or claims he lost his own and pretend to be certain person whose birth has been recorded?
    – Anixx
    Nov 25, 2014 at 14:44
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    @Anixx A photo of a baby would not be very useful anyway! They all look like Winston Churchill. You might be asked to present photo ID (that does not necessarily require citizenship, such as a drivers license) plus a birth certificate. Many years ago it was possible to apply for a birth certificate of a dead person (say one that died as a child) and get false ID issued by the legitimate authorities (eg. as in the novel Day of the Jackal) but that's not possible with modern record keeping. Nov 25, 2014 at 15:05

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