Direct Filing Addresses for Form N-400, Application for Naturalization

Alert: Before sending your package to USCIS, make sure that all the forms you have completed are the current acceptable edition. USCIS published new editions for most forms on April 1, 2024. If you downloaded or printed your forms before April 1, you should verify the current edition date, because we will no longer accept a prior edition. The current acceptable edition can be found under the Edition Date section listed on each form’s webpage.

You can also find the edition date at the bottom of the page on the form and instructions. For each form that you are submitting, make sure that all pages are from the same form edition. If any of the form’s pages are from a different form edition, we may reject your form. Watch USCIS Forms: Download the most recent version! to see how to ensure your form is acceptable.

For additional guidance on filing paper-based forms at the Lockbox and how to avoid or correct common errors before you file, please visit the Five Steps to File at the USCIS Lockbox webpage.

When you submit Form N-400 on paper, we will mail you a USCIS Account Acceptance Notice with instructions on how to create an online account to track and manage your case. We will process your application even if you do not create an online account, but we encourage you to create and access your online account. We will continue to mail you copies of notifications about your case.

• Being a current or former member of the military;
• Being a spouse of a current member of the military; or
• Being a spouse, parent or child of a deceased member of the military

USCIS Chicago Lockbox

U.S. Postal Service (USPS):

USCIS
Attn: Military N-400
P.O. Box 4446
Chicago, IL 60680-4446

FedEx, UPS, or DHL deliveries:

USCIS
Attn: Military N-400 (Box 4446)
131 S. Dearborn, 3rd Floor
Chicago, IL 60603-5517

• Being a current or former service member residing outside of the United States and you are applying for an advance parole document at the same time you file your Form N-400

USCIS Elgin Lockbox

U.S. Postal Service (USPS):

USCIS
Attn: N-400
P.O. Box 4060
Carol Stream, IL 60197-4060

FedEx, UPS, and DHL deliveries:

USCIS
Attn: N-400 (Box 4060)
2500 Westfield Drive
Elgin, IL 60124-7836

USCIS Phoenix Lockbox

U.S. Postal Service (USPS):

USCIS
Attn: N-400
P.O. Box 21251
Phoenix, AZ 85036-1251

FedEx, UPS, and DHL deliveries:

USCIS
Attn: N-400 (Box 21251)
2108 E. Elliot Rd.
​​​​​​​Tempe, AZ 85284-1806

USCIS Dallas Lockbox

U.S. Postal Service (USPS):

USCIS
Attn: N-400
P.O. Box 660060
Dallas, TX 75266-0060

FedEx, UPS, and DHL deliveries:

USCIS
Attn: N-400 (Box 660060)
2501 S State Hwy 121 Business
Suite 400
Lewisville, TX 75067-8003

USCIS Chicago Lockbox

U.S. Postal Service (USPS):

USCIS
Attn: N-400
P.O. Box 4380
Chicago, IL 60680-4380

FedEx, UPS, and DHL deliveries:

USCIS
Attn: N-400 (Box 4380)
131 S. Dearborn, 3rd Floor
Chicago, IL 60603-5517