U.S. Immigration Brief

GENERAL INFORMATION · USCIS TERMINOLOGY

USCIS receipt numbers and A-Numbers identify different things

Federal forms and online tools may ask for a receipt number, an Alien Registration Number, or both. They are not interchangeable: one identifies a case, while the other identifies a person in immigration records.

Editorial illustration representing USCIS case and identity numbers

Editorial topic illustration. It does not depict a real notice, receipt number, A-Number, applicant, immigration file, Green Card, or agency action.

By U.S. Immigration Brief Editorial DeskLast verified August 26, 2026

A receipt number belongs to a case

USCIS describes the receipt number as a unique 13-character identifier that it provides for each application or petition it receives. The format is three letters followed by 10 numbers. Examples of the letter prefixes listed by USCIS include EAC, WAC, LIN, SRC, NBC, MSC, and IOE.

Because the number identifies a particular filing, one person may have more than one receipt number when USCIS is tracking more than one application, petition, or request. USCIS’s Case Status Online tool uses the receipt number to retrieve updates about that specific case.

An A-Number belongs to a person’s immigration record

USCIS uses the term “Alien Registration Number,” commonly shortened to A-Number, as a person-level identifier in federal immigration records. Official USCIS services may request an A-Number in addition to a receipt number. For example, USCIS’s immigrant-fee service uses an A-Number and a State Department case ID, while USCIS e-request tools list an A-Number separately from a receipt number.

An A-Number is not proof that a benefit was granted, and a receipt number is not a substitute for an A-Number. Each number has a different recordkeeping function.

The numbers appear together because people and cases are linked

A federal system may need to identify both the person and the specific filing. USCIS’s public e-request pages illustrate that distinction by listing “Receipt Number” and “A-Number (if applicable)” as separate fields. The receipt number points to the case being discussed; the A-Number, when one exists and is requested, points to the person’s broader immigration record.

Do not use examples as real identifiers

USCIS displays sample formats, such as EAC followed by 10 digits for a receipt number and an “A” followed by digits for an A-Number. Those examples demonstrate formatting only. They do not identify a real person or case, and this article intentionally does not reproduce any reader’s identifiers.

Primary federal sources

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