Quick Answer: What Is an I-551 Number?
The I-551 number is the document or card number printed on a Permanent Resident Card (Green Card). The Permanent Resident Card is officially Form I-551, and its document number typically contains 13 characters: three letters followed by 10 numbers.
The I-551 document number is different from the A-Number, which may appear on the card as the USCIS Number. The location of the I-551 number can vary depending on the Green Card design or generation.
What Is the I-551 Document Number?
The I-551 document number is the identifying number printed on a Permanent Resident Card, Form I-551. Depending on the form or organization asking for it, you may also see this identifier described as the I-551 number, I-551 card number, Permanent Resident Card number, or Green Card number.
The number typically contains 13 characters: three letters followed by 10 numbers. It identifies the specific Green Card document rather than the cardholder personally.
Because several different numbers can appear on a Green Card, the I-551 document number should not automatically be treated as the same thing as the A-Number or USCIS Number. Those identifiers serve a different purpose.
The exact placement of the document number can vary depending on the Green Card design or generation.
I-551 Number vs. A-Number vs. USCIS Number vs. Receipt Number
No. The I-551 document number, A-Number, and USCIS receipt number are not the same identifier. A Green Card can contain or relate to several numbers, so it is important to use the one specifically requested.
| Number | What it identifies | Typical location |
|---|---|---|
| I-551 document/card number | The physical Permanent Resident Card | Green Card |
| A-Number | The person’s Alien Registration Number | Green Card and immigration records |
| USCIS Number | The A-Number when it is displayed as the USCIS Number on a Green Card | Green Card |
| USCIS receipt number | A particular USCIS application, petition, or case | Form I-797 or I-797C notice |
| USCIS Online Account Number | A person’s USCIS online account | USCIS online account or certain USCIS notices |
The USCIS Number shown on a Green Card generally corresponds to the cardholder’s A-Number. It identifies the person, while the I-551 document number identifies the card.
For example, in the older Green Card specimen shown below, USCIS# 000-000-318 appears on the front of the card, while the separate I-551 document number, LIN0000000319, appears on the back.
A USCIS receipt number is different again. USCIS assigns a receipt number to a particular application, petition, or request so the agency can identify and track that case.
The USCIS Online Account Number is also separate from these identifiers. Use the number specifically requested by the form or organization rather than substituting one identifier for another.
Where Is the I-551 Number on a Green Card?
The location of the I-551 document number can vary by Green Card design. On the older Permanent Resident Card specimen shown below, the document number appears on the back of the card within the machine-readable information.
In this example, LIN0000000319 is the I-551 document number. The front of the same card separately shows USCIS# 000-000-318, which is the cardholder’s USCIS Number/A-Number. These are different identifiers.
Green Card layouts have changed over time, so an older or newer card may present identifying information differently. Do not rely only on a specific corner or position when looking for the number.
When a form asks for an I-551 number, card number, or document number, check which identifier it requires and compare it with the information printed on your particular Permanent Resident Card.
Example of an older Permanent Resident Card showing the I-551 document number on the back and the USCIS Number/A-Number separately on the front.
What Does an I-551 Number Look Like?
An I-551 document number generally contains 13 characters, beginning with three letters followed by 10 numbers.
In the older USCIS specimen shown above, the I-551 document number is:
LIN0000000319
The combination of letters and numbers helps distinguish the document number from the A-Number/USCIS Number, which is a different identifier assigned to the person.
Do not use the first three letters to determine a service center or interpret the cardholder’s immigration case history.
Is the I-551 Number the Same as the Green Card Number?
People often use “I-551 number,” “Green Card number,” “card number,” and “document number” to describe the document identifier printed on the Permanent Resident Card.
However, “Green Card number” can be used loosely, which sometimes causes confusion. If a form specifically asks for a document number or I-551 number, do not automatically enter the USCIS Number/A-Number or a USCIS receipt number.
Check the wording on the form and the identifying information on your Green Card before entering a number.
When Is the I-551 Document Number Used?
The I-551 document number may be requested when information from a Permanent Resident Card needs to be recorded or verified.
One common example is employment verification. A Permanent Resident Card, Form I-551, is a List A document for Form I-9, meaning it can establish both identity and employment authorization. Employers using E-Verify may also enter information from the card during the verification process.
The document number may also be requested in other government or administrative processes that require information from a Green Card.
When a form specifically asks for the document or card number, provide the identifier requested rather than automatically entering your A-Number or USCIS receipt number.
Which I-551 Number Should You Use After Getting a New Green Card?
A newly issued Green Card may have different document information, including its I-551 document number. The I-551 number identifies the card document, while the A-Number identifies the person in immigration records.
If you receive a replacement or renewed Permanent Resident Card, use the document information printed on the new card when a form asks for the current I-551 document number.
What If You Have Temporary I-551 Evidence Instead of a Green Card?
If you do not have a usable physical Green Card and instead need temporary proof of permanent resident status, the document may be different from the physical card discussed on this page.
See our I-551 (ADIT) Stamp guide for information about temporary Green Card evidence.
FAQs About the I-551 Number
Is the I-551 number the same as the A-Number?
No. The I-551 document number identifies the Permanent Resident Card, while the A-Number identifies the person in U.S. immigration records. On many Green Cards, the A-Number appears as the USCIS Number.
How many digits are in an I-551 number?
An I-551 document number is generally 13 characters, not 13 digits. It typically begins with three letters followed by 10 numbers.
Where is the I-551 number on an older Green Card?
The location can vary by card generation. On some older Permanent Resident Cards, the I-551 document number appears on the back within the machine-readable area, while the USCIS Number/A-Number appears separately on the front.
Is the I-551 number the same as a USCIS receipt number?
No. A USCIS receipt number identifies a specific application, petition, or request filed with USCIS. The I-551 document number identifies the Permanent Resident Card itself.
Need Information About Your Green Card?
If you want to understand the current Permanent Resident Card, see our U.S. Green Card Guide. If your card is expired, lost, or damaged, review our Green Card renewal or Green Card replacement guides. If you need temporary proof of permanent resident status, see our I-551 (ADIT) Stamp Guide.
