To address a letter to USCIS, copy the full address block from the filing-address page for your specific form on the USCIS website: the agency name, the “Attn” line printed for your eligibility category, and either the P.O. Box (for USPS) or the street address (for FedEx, UPS, or DHL). Get any of those elements wrong and the package can be rejected without appeal, and a rejected filing does not keep its original receipt date.
Find the Address for Your Specific Form
There is no single mailing address for USCIS. Every form has its own filing-address page on the agency’s website, and the correct destination depends on the form you are filing and the eligibility category you are claiming. For many forms it also depends on where you live. The I-485 page, for instance, lists different Lockbox addresses based on your state of residence and whether you are filing family-based, employment-based, or investor.
Most paper filings go to a USCIS Lockbox, a high-volume intake facility that scans documents, verifies the fee, and forwards the package to the appropriate Service Center or Field Office.
Check the Address the Day You Mail
USCIS changes its filing locations regularly. As recently as February 2026, the agency shifted the filing destination for several form types, including Forms I-589 and I-918. Confirm the address on the USCIS website the day you actually drop the package in the mail, not weeks earlier when you started assembling it. The DHS Lockbox tip sheet warns that mailing to the wrong address can cause a processing delay or an outright rejection.
How to Write the Address on the Envelope
Copy the address block exactly as the USCIS page lists it. Do not abbreviate any part of it, and include the box number or suite designation. A typical block looks like this:
USCIS
Attn: NFB
P.O. Box 21281
Phoenix, AZ 85036-1281
The “Attn” line is not decorative. It identifies your form type and eligibility category and tells Lockbox staff which processing unit should receive the package. USCIS also recommends marking both the envelope and any cover letter with the form number and the type of submission, for example, “Original Submission, Form I-485.”
Put your return address in the upper-left corner, and use the same address you have on file with USCIS. If you have moved since your last filing, update your address with USCIS first (see below) before you mail anything new.
Use the full nine-digit ZIP+4 on both the recipient and return addresses. Automated postal sorting is more accurate with the extended ZIP, and it reduces the risk that your package ends up in the wrong processing branch within a shared ZIP code area.
USPS Address vs. Courier Address
Each Lockbox has two different addresses, and they are not interchangeable. The USPS address is a P.O. Box. The address for private couriers such as FedEx, UPS, and DHL is a physical street location. Sending a FedEx package to a P.O. Box, or a USPS package to a street address, can delay or derail delivery.
The Phoenix Lockbox illustrates the split for certain I-485 filings:
- USPS: USCIS, Attn: NFB, P.O. Box 21281, Phoenix, AZ 85036-1281
- FedEx/UPS/DHL: USCIS, Attn: NFB (Box 21281), 2108 E. Elliot Rd., Tempe, AZ 85284-1806
Whichever carrier you choose, use a service with delivery tracking. The tracking record proves the date USCIS received your package, which matters if a filing deadline is close. USCIS will eventually mail a Form I-797C, Notice of Action, as official confirmation of receipt, but that notice typically arrives several weeks after delivery. Your tracking confirmation is the interim proof.
One Envelope for Related Forms, Separate Packages Otherwise
You can mail related forms together, such as an I-485 and a concurrently filed I-765 in the (c)(9) employment-authorization category. Do not combine unrelated forms in the same envelope; forms are unrelated when the decision on one does not affect the other. If you mail multiple related cases together, separate each case with a rubber band and include separate payment authorizations for each form. When filing for several family members, keep each person’s complete package bundled on its own inside the larger envelope.
Consider Filing Online Instead
Some of the most commonly filed forms can be submitted through a USCIS online account, which removes the mailing question entirely. That list includes Form I-130 (Petition for Alien Relative), Form I-765 (Employment Authorization), Form I-539 (Change of Nonimmigrant Status), and Form I-90 (Green Card Replacement). USCIS publishes and updates the full list of forms available for online filing on its website.
Where Not to Send Mail
If USCIS sends you a Request for Evidence or a Notice of Intent to Deny, do not send your response to a Lockbox. The notice itself lists the specific return address, often a Service Center, along with a deadline. Follow those instructions exactly. Appeals and motions are typically filed on Form I-290B at the address specified in the denial notice.
What Happens If You Get the Address Wrong
USCIS will reject a filing that arrives at the wrong location, and a rejection cannot be appealed. The package comes back to you, but it does not keep its original receipt date. When you fix the problem and refile, USCIS treats the corrected submission as a brand-new filing with a new date and a new fee.
Losing the filing date can be costly. For immigrant visa petitions, the receipt date often establishes your priority date, which is your place in line for a visa number. A rejection pushes that date forward to whenever you successfully refile.
Keep Your Address Current After You Mail
Federal law requires most noncitizens in the United States to notify USCIS of an address change within 10 days of moving. Failing to do so is a misdemeanor and can trigger removal proceedings. The fastest way to update your address is the USCIS online Change of Address (E-COA) tool, which processes changes almost immediately. Filing a paper Form AR-11 by mail is also permitted, but the processing delay increases the risk that USCIS will send important correspondence, including interview notices and approval documents, to your old address.
If you move after mailing a filing but before receiving your receipt notice, update your address online as soon as you can. The E-COA tool can update your general address record and any pending cases at the same time.