Your Certificate of Naturalization number is printed in the upper-right corner of the certificate itself — Form N-550 for the original document, Form N-570 for a replacement.1U.S. Citizenship and Immigration Services. History of the Certificate of Naturalization (1906-1956) If you have the physical document, that’s where to look. If you don’t, there are faster ways to find your Certificate of Naturalization number than filing for a new certificate and waiting months for it to arrive.
What the Number Looks Like, and What It Isn’t
The certificate number identifies the document. Your Alien Registration Number, or A-number, identifies you and tracks your immigration file at USCIS. They are two different numbers, and forms that ask for one often don’t want the other. Before you go hunting for your certificate number, read the form again to be sure that’s what it’s asking for.
On certificates issued since 1941 (Form N-550), the number sits in the upper-right corner. Older certificates place it differently. The first standardized version, Form 2207, was used from 1906 to 1929 and printed the number at the top left, labeled as a “C-number.”2National Archives. History of the Certificate of Citizenship, 1790-1956 Certificates issued before September 1906 had no standard format and may not carry a certificate number at all. If you’re holding one of those, a USCIS field office can help identify what number applies.
If You Don’t Have the Certificate in Front of You
A missing certificate doesn’t automatically mean filing for a replacement. Try the faster options first.
Look Through Your Own Records
The number may already be written down somewhere you’ve forgotten. If you’ve ever applied for a U.S. passport, filed an I-9 for a job, or enrolled in a federal program, you probably copied the number onto that paperwork. Old photocopies of the certificate, scans saved on a computer, or a phone photograph will all work. This is the step people skip, and it’s the one that most often solves the problem in an afternoon.
Request Your Records from USCIS
You can ask USCIS for a copy of your own immigration records under the Freedom of Information Act or the Privacy Act. As of January 2026, requests are submitted online through the FIRST system at first.uscis.gov.3U.S. Citizenship and Immigration Services. Request Records through the Freedom of Information Act or Privacy Act You don’t have to ask for everything — a targeted request for the naturalization record moves faster than a request for a full file. There’s no fee, which makes this the cheapest way to get the number if all you need is the number. Response times are unpredictable and can run from weeks to months, so this route works when you have time, not when you have a deadline.
Call the USCIS Contact Center
When you need proof of citizenship quickly, call the USCIS Contact Center at 800-375-5283 (TTY 800-767-1833), Monday through Friday, 8 a.m. to 8 p.m. Eastern.4U.S. Citizenship and Immigration Services. USCIS Contact Center If the agent can’t handle it by phone, they can schedule an in-person appointment at a field office. Those appointments are available specifically when you need proof of immigration status for work or travel.
When You Actually Need a Replacement Certificate
If you need the physical document back — not just the number — file Form N-565, Application for Replacement Naturalization/Citizenship Document.5U.S. Citizenship and Immigration Services. N-565, Application for Replacement Naturalization/Citizenship Document USCIS reissues the certificate as Form N-570, which carries the same legal weight as the original N-550.6U.S. Citizenship and Immigration Services. Commonly Used Immigration Documents
Filing online costs $505; the paper version costs $555.7U.S. Citizenship and Immigration Services. Frequently Asked Questions on the USCIS Fee Rule The fee is waived if you’re correcting a typographical or clerical error USCIS made on the original certificate.5U.S. Citizenship and Immigration Services. N-565, Application for Replacement Naturalization/Citizenship Document If paying the fee would be a genuine hardship, file Form I-912 for a fee waiver at the same time you submit the N-565 — USCIS will not process a fee waiver request that arrives after the main application.8U.S. Citizenship and Immigration Services. I-912, Request for Fee Waiver
Processing times for Form N-565 can run several months, which is why the FOIA or Contact Center routes are usually better if the number itself is all you’re after.
Check Which Number the Form Actually Wants
The certificate number comes up less often than people assume. It shows up when you apply for a U.S. passport (where you submit the physical certificate as proof of citizenship), on some government benefit applications, and in employment verification. Voter registration usually asks for proof of citizenship, not the specific certificate number. Many forms that mention immigration documentation actually want your A-number. Confirm which one the form is asking for before spending time or money to recover the wrong one.