Parents often hear about “the citizenship certificate” as if there were one form. There are two, and they do different jobs. Form N-600 documents citizenship a person already has. Form N-600K asks USCIS to naturalize a child who lives abroad and did not become a citizen automatically. Picking the wrong one wastes months.

Form N-600: proof of citizenship you already have

The N-600 is for people who are already citizens, either at birth abroad to a U.S. citizen parent or automatically after birth. The automatic route is INA 320, 8 U.S.C. 1431: a child born abroad becomes a citizen when at least one parent is a citizen, the child is under 18 and the child is residing in the United States in the citizen parent’s legal and physical custody after a lawful admission for permanent residence.

Our guide to citizenship derivation for Texas families covers this path in detail.

Form N-600K: naturalization for a child living abroad

INA 322, 8 U.S.C. 1433, lets a U.S. citizen parent apply for naturalization on behalf of a child born and living outside the United States who has not acquired citizenship automatically. The child must be under 18, live abroad in the applicant’s custody and be temporarily present in the United States after a lawful admission. The child becomes a citizen only after approval and the oath.

The parent or a grandparent must also meet a physical presence test, explained in our article on INA 322 physical presence.

A quick way to tell them apart

  • Child lives in the United States as a green card holder with a citizen parent: usually INA 320 and Form N-600.
  • Child lives abroad and was not a citizen at birth: usually INA 322 and Form N-600K.
  • Adult who was already a citizen as a child: Form N-600 as proof.

n600k.com has a side-by-side comparison of N-600K and N-600 and of INA 322 and INA 320.

Filing practicalities

USCIS’s N-600 page states that people applying from outside the United States, requesting a fee waiver, or filing as members or veterans of the military on their own behalf cannot currently file the N-600 online. Fees change, so confirm the amount on the USCIS fee schedule before filing. For the evidence list, n600k.com keeps an N-600K document checklist, and its home page explains the full process.

Adopted children and other special cases

Adopted children can use both sections if the adoption meets the statutory definition; see our guide for adoptive families. For the broader picture of how birth, derivation and naturalization relate, read naturalization vs. citizenship.

Frequently asked questions

Can a child who lives in Dallas use the N-600K? Generally no. INA 322 is for children residing outside the United States; a child living here as a permanent resident usually falls under INA 320.

Does an N-600 make someone a citizen? No. It documents citizenship that already exists. The N-600K, by contrast, leads to naturalization after approval and the oath.

Is the oath required for every N-600K? The statute requires the oath unless an exception applies, such as certain children of members of the armed forces.

Key Takeaways

  • Form N-600 documents citizenship a person already has; Form N-600K naturalizes a child living abroad.
  • INA 320 applies to children residing in the United States as permanent residents with a citizen parent.
  • INA 322 applies to children abroad and requires approval and the oath before age 18.
  • Some N-600 filers, including those abroad, cannot currently file online.
  • Check current fees and evidence lists before filing.

Disclosure: This site collaborates with the law firm that publishes mandamus.com and n600k.com; some articles link to their guides. General information only, not legal advice.

General information only, not legal advice. Immigration law and agency policy change often; confirm current rules before acting. Published October 26, 2026. Official sources checked October 26, 2026.