Where Is the Alien Number on a Green Card

Find the alien number on the front of your green card

Look at the front of your Permanent Resident Card, commonly called a green card. Find the label “USCIS#.”

The number next to that label is usually your 9-digit Alien Registration Number. It may also be called your A-Number, Alien Number, or AR#.

A quick card-reading check:

• Label: USCIS#
• Length: 9 digits
• Location: Front of the green card
• Meaning: Your Alien Registration Number

So, if a form asks for your alien number and you have your green card in front of you, start with the 9-digit number next to USCIS#. Don’t pick a number just because it appears on the card. Green cards contain several numbers, and they don’t all mean the same thing.

What the USCIS# and Alien Registration Number mean

The USCIS# on your green card is generally the same number as your Alien Registration Number.

You may see the names used in different ways:

• Alien Registration Number
• Alien Number
• A-Number
• A#
• AR#
• USCIS number
• USCIS#

For a green card holder, these labels point to the 9-digit number identified as the USCIS# on the card.

That answers the common question, “Is the USCIS number the same as the Alien Number?” In this card-reading context, yes. The USCIS# is the number you’re looking for.

Some paperwork may write the number with an “A” before it. Other forms may ask for the digits only. Follow the format shown in the form. If the form gives no special format, compare the label and number on your card carefully before entering it.

Is the alien number also printed on the back?

Yes. The Alien Number is also shown on the back of the green card.

The front is usually the easiest place to identify it because the number appears under the clear USCIS# label. The back can contain other card details, so it may take more care to match the number.

When checking the back:

1. Look for the same 9-digit number.
2. Compare it with the USCIS# on the front.
3. Don’t assume every long number on the back is your Alien Number.

The number’s position and design can vary by card version. The safest test is still the label and the matching 9-digit number, not the number’s location alone.

Alien number vs. green card number and document number

This is where many forms become confusing.

People often use “green card number” as a general phrase for any number printed on the card. But a form may be asking for a specific number, such as:

• Alien Number or USCIS#: The 9-digit number linked to your immigration record.
• Document number: A separate number connected to the card itself.
• Card number: A term a form may use for the document or card identifier.
• Social Security number: A different number issued for Social Security purposes.

The key distinction is this: the document number is separate from the USCIS#. If a form asks for the document number, don’t automatically enter the 9-digit USCIS#.

So, where is the green card number located? That depends on what the form means by “green card number.” The wording may refer to the USCIS#, or it may refer to the separate document number. Read the form’s label and instructions before choosing a number.

A useful way to avoid mistakes is to write down the exact wording:

• “Alien Number” or “A-Number” → look for the 9-digit USCIS#.
• “USCIS Number” → use the number labeled USCIS#.
• “Document Number” → look for the separate document identifier.
• “Card Number” → check the form instructions instead of assuming it means USCIS#.

Is your alien number the same as your SSN?

No. Your Alien Registration Number is not your Social Security number.

The alien number is the 9-digit number shown as USCIS# on the green card. A Social Security number is a separate identification number. Don’t replace one with the other just because a form asks for an identification number.

This matters on employment, immigration, and other government paperwork. A form may ask for both numbers, or it may ask for only one. Enter each number only in the field that names it.

If you’re looking at your green card, the number to identify as the Alien Number is the one labeled USCIS#, not a Social Security number you may have recorded elsewhere.

Where to look if you do not have your green card

If your card isn’t with you, don’t guess based on another number you remember.

Start by checking the paperwork or record connected to your immigration case. Your Alien Registration Number may also appear as an A-Number, A#, or AR# instead of USCIS#.

If you’re checking a passport, be careful with the wording “Alien Registration number on passport.” A passport number is a travel-document number. It should not be treated as your Alien Number simply because both numbers may be used on paperwork.

The provided card guidance identifies the Alien Number clearly on a green card: it is the 9-digit USCIS# on the front, and it also appears on the back. If you don’t have the card and can’t confirm the number from your immigration records, check the instructions for the form or ask an official immigration source before submitting anything.

How to identify the number requested on common forms

Forms can use similar words for different numbers. Pause at the field and match the wording to the label on your card.

Use this quick guide:

If the form asks for your Alien Number

Enter the 9-digit number labeled USCIS# on the front of your green card. The form may call it an A-Number, Alien Registration Number, or AR#.

If it asks for your USCIS number

Use the same 9-digit number next to USCIS#.

If it asks for your green card or document number

Don’t assume it wants the USCIS#. The research behind this guide identifies the document number separately from the USCIS#. Check the form’s own instructions for the right location and format.

If it asks for your SSN

Use your Social Security number, not the number labeled USCIS#.

Before you submit the form, check the digit count and the label one more time. A nine-digit number can look easy to spot, but a nearby card number can still cause a mix-up.

What to do if you see a 13-digit number on your card

The 13-digit-number question needs a careful answer: the available card information identifies the Alien Number as a 9-digit USCIS#, but it does not identify which green-card number is 13 digits.

That means you shouldn’t assume a 13-digit number is your Alien Number. You also shouldn’t shorten it, remove digits, or enter it in place of the USCIS# without clear instructions.

If a form asks for a 13-digit number, check:

• The exact name of the field.
• The form’s instructions.
• Whether it asks for a card number, document number, or another identifier.
• Whether the form gives a sample format.

The right number depends on what the form is asking for. Before submitting paperwork, verify that exact field with the relevant form instructions or an official immigration source.