US Visa WatchWhat Is My Permanent Resident Card Number
Your permanent resident card number is generally on the back of your green card, not the 9-digit number printed on the front. It is usually a 13-character code made up of three letters followed by 10 numbers.
You may also see this called the green card number, document number, or I-551 Permanent Resident Card number. These names can be confusing because your card also shows a USCIS number and, in many cases, an A-Number.
The quickest way to sort them out is to compare the front and back:
| Card location | Number you may see | What it is usually used for |
|---|---|---|
| Back of the card | 13-character card or document number | Form I-9, travel forms, and requests for the Permanent Resident Card number |
| Front of the card | 9-digit USCIS number | USCIS identification and forms that specifically ask for the USCIS number |
| Front or other immigration records | A-Number | Forms that specifically ask for your Alien Number or A-Number |
Where to find the permanent resident card number
Turn your card over and look at the bottom section. The permanent resident card number appears in the machine-readable zone, often called the MRZ. This is the area with rows of letters, numbers, and `<` symbols.
The number is generally found in the first line of that machine-readable area. Depending on the card layout, you may also see the same card or document number printed elsewhere on the back.
Look for a code that follows this basic pattern:
`ABC1234567890`
That example shows three letters followed by 10 numbers. It is only a pattern example, not a real card number.
Some descriptions call this a 13-digit code, while others call it a 13-character code. The second description is clearer when the code includes letters. What matters for most forms is that this is the number printed on the back of the card.
If you are holding the card in front of you, do not assume the largest or easiest-to-read number is the one a form wants. Flip it over first.
What the card number looks like on a green card
A green card can show several different identifiers. The card or document number is usually the one that looks like a longer code with letters and numbers together.
A simple visual decoder looks like this:
- Back: longer card or document number, commonly 13 characters
- Front: 9-digit USCIS number on cards issued after May 10, 2010
- Front or immigration paperwork: A-Number, also called an Alien Number
The permanent resident card number may be labeled in different ways outside the card itself. A form might call it:
- Green card number
- Permanent resident card number
- Permanent resident number
- Document number
- I-551 number
- Card number
These labels often point to the number on the back of the card. Still, read the form carefully. The wording matters more than the nickname people use online.
Do not remove spaces or add symbols unless the form gives different instructions. If the form accepts only letters and numbers, enter the code without the `<` symbols from the machine-readable zone.
Card number versus USCIS number and A-Number
These numbers are related to your immigration record, but they are not automatically interchangeable.
The permanent resident card or document number
This is the code on the back of the Permanent Resident Card. It is commonly described as a 13-character code. Form I-9 instructions identify the document number for a Permanent Resident Card on the back of the card.
The USCIS number
The USCIS number is a unique 9-digit number shown on the front of Permanent Resident Cards issued after May 10, 2010.
Because it appears prominently on the front, people sometimes call it the green card number. That can cause trouble. If a form asks for the USCIS number, use the 9-digit number. If it asks for the card number or document number, check the back.
The A-Number
The A-Number, or Alien Number, is a separate immigration identifier. A form may write it as:
- A-Number
- Alien Number
- A#
- A-number
If the form asks for an A-Number, do not substitute the 13-character card number or the 9-digit USCIS number just because one of them is easier to find.
The safest rule is simple: match the number to the exact label on the form.
How to identify the number for Form I-9
For Form I-9, a Permanent Resident Card is a document that can be used to show identity and employment authorization. When the form asks for the document number for that card, use the number printed on the back of the Permanent Resident Card.
Do not use the front 9-digit USCIS number unless the form separately asks for a USCIS number.
Before entering it, check these details:
- Turn the card over.
- Find the card or document number in the back section.
- Compare each letter and number carefully.
- Keep letters as letters. For example, do not turn an `O` into a zero.
- Do not copy the `<` symbols unless the form specifically asks for the machine-readable line exactly as shown.
If a person helping with Form I-9 asks for your “green card number,” point to the back-of-card number and confirm that this is what they mean by the document number. The labels are often used loosely in conversation.
Finding the number on the back machine-readable zone
The machine-readable zone is the block at the bottom of the card designed to be read by scanning systems. It contains information in lines made from capital letters, numbers, and filler symbols.
The permanent resident card number appears in the first line of this zone.
This area can look crowded, so it helps to work slowly:
- Find the first line at the bottom of the back.
- Look for the longer code made up of letters and numbers.
- Compare it with any card or document number printed elsewhere on the back.
- Ignore filler symbols such as `<` unless the form tells you to include them.
A blurry scan, glare, or worn card can make individual characters hard to tell apart. If you cannot read the number with confidence, do not guess. Check another copy of the card or ask the organization handling the form what format it expects.
Which number to use for airline and travel forms
Travel and airline forms do not all use the same label. Read the field name before entering anything.
If the form asks for your:
- Green card number
- Permanent resident card number
- Permanent resident number
- Document number
- I-551 number
the requested number is generally the longer code on the back of the card.
If it specifically asks for your USCIS number, enter the 9-digit number shown on the front of cards issued after May 10, 2010.
If it asks for your A-Number or Alien Number, use that identifier instead. Do not treat “USCIS number,” “A-Number,” and “card number” as automatic synonyms.
Some travel systems may use different wording or limit the number of characters. If the field rejects the back-of-card number, look for instructions beside the field. A system that asks for a case, receipt, or USCIS number may be asking for a different identifier.
How older and newer Permanent Resident Cards may differ
Card designs and labels can change over time. Newer Permanent Resident Cards issued after May 10, 2010 show a unique 9-digit USCIS number on the front.
Older cards may have a different layout, different labels, or a different placement for the information. The back-of-card machine-readable area remains an important place to check for the card or document number, but you should not assume every older card looks exactly like a newer one.
When your card does not match an online picture:
- Check the back first.
- Look at the machine-readable zone at the bottom.
- Read the form’s exact label.
- Do not replace a requested card number with the front USCIS number without checking.
If a form or agency gives its own instructions for an older card, follow those instructions. This article is only a practical guide to identifying the numbers, not legal advice.
What to check when a form asks for a document, receipt, or permanent resident number
The word number by itself is not enough. Look at the full phrase.
If it asks for a document number
Use the number on the back of the Permanent Resident Card. This is the usual answer for the document number on a Permanent Resident Card for I-9.
If it asks for a permanent resident card number
Use the back-of-card code, often described as the 13-character card number or I-551 number.
If it asks for a USCIS number
Use the 9-digit number on the front of newer Permanent Resident Cards.
If it asks for an A-Number or Alien Number
Use the A-Number. Do not assume it is the same as the card number.
If it asks for a receipt number
A receipt number may refer to an immigration filing or case record rather than the number printed on your Permanent Resident Card. Check the form’s instructions and the document it names. Do not automatically copy the card number.
Before submitting any form, compare the label one more time: card or document number, USCIS number, or A-Number. Matching the exact label is the best way to choose the right number.