To find out which USCIS office issued your green card, look at the three-letter prefix on the 13-character receipt number printed on the card. Those three letters identify the service center that processed your case. The same prefix appears on every Form I-797 notice USCIS mailed you during the application, and you can look up your case by that number in the USCIS Case Status Online tool.
Where to Find the Code on Your Card
On current green cards, the receipt number sits on the back of the card, in the first line of the machine-readable text near the bottom. It runs 13 characters: three letters followed by ten digits. The three letters are what you want.
If your case was filed through a USCIS online account, the prefix reads “IOE” instead of a geographic code. IOE means the case moved electronically rather than through a physical service center, so it won’t map to a specific building. It still works as a valid receipt number for tracking.
What Each Three-Letter Code Means
USCIS runs several service centers that handle green card applications by mail, electronically, or through a lockbox. None of them take walk-ins or hold interviews.1U.S. Citizenship and Immigration Services. Glossary The prefixes you’re most likely to see:
- SRC — Texas Service Center (originally “Southern Regional Center”)
- LIN — Nebraska Service Center (named for Lincoln, Nebraska)
- EAC — Vermont Service Center (originally “Eastern Adjudication Center”)
- WAC — California Service Center (originally “Western Adjudication Center”)
- MSC — National Benefits Center (originally “Missouri Service Center”)
- NBC — National Benefits Center (newer code for the same facility)
- IOE — Electronic filing through a USCIS online account
The parenthetical names explain the mismatches. USCIS has renamed and reorganized offices over the years, but the legacy codes stuck. If your card carries a code not on this list, it likely belongs to a specialized processing unit, and the USCIS Contact Center can tell you which one.
If You Can’t Read the Card
Every action USCIS takes on your case generates a Form I-797, Notice of Action, with the same 13-character receipt number displayed on the front.2U.S. Citizenship and Immigration Services. Receipt Number If your card is lost or the machine-readable text is worn, your old I-797s are the fastest backup.
You can also enter the receipt number into the Case Status Online tool at egov.uscis.gov to see which center is handling your case.3U.S. Citizenship and Immigration Services. Case Status Online Type the 13 characters without dashes. If your file was transferred between centers at any point, the online history will show that too.
When You Need the Full Answer From USCIS
If the receipt number and online tool still don’t tell you what you need, request your records directly. A Freedom of Information Act or Privacy Act request, filed on Form G-639, gets you your Alien File — the A-File — which lists every office that touched your case.4U.S. Citizenship and Immigration Services. Request Records through the Freedom of Information Act or Privacy Act
A few things worth knowing before you file. Targeted requests move faster than requests for the entire A-File, so ask only for what you need. Include your Alien Registration Number (A-Number) if you have it, because it helps USCIS pull the file. Cost is rarely an obstacle: USCIS provides the first 100 copies and the first two hours of search time at no charge, and Privacy Act requests carry no search or processing fees.5U.S. Citizenship and Immigration Services. Form G-639, Freedom of Information/Privacy Act Request If you have a hearing before an immigration judge, attach the Notice to Appear and USCIS can expedite.
Prefer to talk to someone? The USCIS Contact Center takes calls at 800-375-5283 and runs the “Emma” virtual assistant on the USCIS website. Emma handles basic questions in English and Spanish and can hand you off to a live agent for anything specific.6U.S. Citizenship and Immigration Services. USCIS Contact Center Keep your receipt number and A-Number in front of you when you call.
For situations that need someone to look you in the eye, schedule an in-person appointment at a field office through your account at my.uscis.gov. The old self-service InfoPass system was retired, so requests now go through the online portal or through a Contact Center agent. An in-person appointment makes sense when your records span multiple offices or when you need to hand over original documents.
If the Office Code or Anything Else Is Wrong
When the data on your card doesn’t match reality — wrong office code, misspelled name, wrong date — you correct it by filing Form I-90, Application to Replace Permanent Resident Card. The path depends on who made the mistake.7U.S. Citizenship and Immigration Services. Immigration Documents and How to Correct, Update, or Replace Them
If USCIS caused the error, choose filing category 2.d or 3.d (“My existing card has incorrect data because of Department of Homeland Security error”), send in the card that has the error along with proof of the correct information, and pay no filing fee. If the error is on your side, such as a legal name change since the card was issued, you pick a different category and pay the current filing fee. Check the Form I-90 page for the fee in effect when you file, because USCIS adjusts fees from time to time.
Replacement cards can take several months to process, so don’t sit on an error you’ve already spotted. Fixing it while you have no pressing deadline is far easier than fixing it in the weeks before a naturalization interview or an international trip.