How to Read Your USCIS Receipt Number (NBC, IOE, EAC, WAC)
When I got my Receipt Notice after filing for a green card, the first thing I did was stare at that 13-character string — NBC2412345678 — trying to figure out what it meant. The USCIS website didn't explain it clearly, and forums had conflicting information. After going through the process myself and analyzing hundreds of case numbers from the community, here's everything you need to know.
What Is a USCIS Receipt Number?
A USCIS receipt number is a 13-character identifier assigned to every immigration application when it is accepted. It appears on your Receipt Notice (Form I-797) and is used to track your case on the USCIS website. The number is not random — each part of it encodes specific information about your application.
Breaking Down the Structure
A standard paper-filed receipt number looks like this: NBC 24 012 3456789
- NBC — Service center code (3 letters)
- 24 — Last two digits of the fiscal year (FY2024)
- 012 — USCIS workday counter (business days into the fiscal year)
- 3456789 — Sequential case number (7 digits)
📌 The U.S. fiscal year runs from October 1 to September 30. So FY2024 = October 1, 2023 through September 30, 2024. A receipt number starting with 24 was filed during that window.
Service Center Codes Explained
The first three letters identify which USCIS service center is handling your case. Each center processes different form types and has its own processing timeline.
| Code | Service Center | Location |
|---|---|---|
| NBC | National Benefits Center | Lee's Summit, MO |
| EAC / VSC | Vermont Service Center | St. Albans, VT |
| WAC | California Service Center | Laguna Niguel, CA |
| LIN | Nebraska Service Center | Lincoln, NE |
| TSC / SRC | Texas Service Center | Dallas, TX |
| YSC | Potomac Service Center | Arlington, VA |
| IOE | USCIS ELIS (Electronic) | e-filed |
| MSC | National Benefits Center (legacy) | Lee's Summit, MO |
What Is IOE and Why Is It Different?
If your receipt number starts with IOE, your application was submitted online through USCIS's Electronic Immigration System (ELIS). IOE numbers do not follow the same fiscal year and workday structure as paper-filed receipts. The digits after IOE are a sequential system ID, not a date-encoded counter.
This means you cannot estimate your filing date from an IOE number alone. The filing date will be clearly printed on your Receipt Notice (Form I-797C).
How to Estimate Your Filing Date (Paper Receipts Only)
For paper-filed receipts (NBC, EAC, WAC, etc.), the 3-digit workday counter tells you approximately how many USCIS business days into the fiscal year your case was received. Since USCIS counts Monday through Friday, excluding federal holidays, you can work backward from October 1 to get an approximate date.
For example, a workday counter of 012 in FY24 means roughly the 12th business day after October 1, 2023 — which lands around October 17, 2023. This is an estimate only; USCIS does not publish the exact business day calendar.
🔍 Use the Receipt Decoder tool on this site to automatically decode your receipt number and get an estimated filing date.
Why Does the Service Center Matter?
Processing times vary significantly between service centers. The same form type — say, I-765 (Employment Authorization) — can take 2 months at one center and 6 months at another, depending on current workload. USCIS publishes processing time estimates by center at egov.uscis.gov/processing-times.
Your case can also be transferred between centers. If that happens, you may receive a new receipt number with a different prefix, or USCIS may keep the original number but route it internally. Transfer events appear as BC, BA, or BB codes in your case event log.
Frequently Asked Questions
Can I look up my case without a receipt number?
No. USCIS case tracking requires a receipt number. If you lost your Receipt Notice, contact USCIS to request a duplicate.
Is the receipt number the same as my A-Number?
No. Your Alien Registration Number (A-Number) is a permanent 8- or 9-digit identifier tied to you as an individual. Your receipt number is tied to a specific application filing and changes for each petition you submit.
My prefix isn't listed above — what does it mean?
Older or less common prefixes (like MSC or SRC) may appear on legacy cases or specific visa categories. If you see an unfamiliar prefix, check the USCIS website or consult an immigration attorney.