Yes, you can file Form N-400 (Application for Naturalization) by mail. USCIS still accepts paper applications, though the agency now prefers online filing, which costs $50 less. Mail filing remains the required path if you're applying for a fee waiver or reduction based on income.
Table of Contents
- Where to Send Your Application
- Fees and How to Pay
- The Correct Form and Required Documents
- The Civics Test and After Filing
Where to Send Your Application
You must mail your Form N-400 to one of two USCIS lockbox facilities, determined by your state. Western states use Phoenix, Arizona; eastern states use Lewisville, Texas. Mailing to the wrong address causes processing delays, so verify your state's correct lockbox before sending. Include Form G-1145 (Notification of Application/Petition Acceptance) with your application to receive an email or text message confirming USCIS received it..
Fees and How to Pay
Filing fees depend on your circumstances. The standard paper-filing fee is $640; online filing costs $590. If your household income falls between 150% and 400% of the federal poverty line, the reduced fee is $380. You pay nothing if you qualify for a fee waiver (income at or below 150% of poverty). Payment by check or money order is no longer accepted for mail applications. Instead, submit your fee using form G-1450 (to pay by credit or debit card) or Form G-1650 (to pay by ACH bank transfer).
The Correct Form and Required Documents
Only the 09/09/26 edition of Form N-400 is currently valid; earlier versions are rejected. When you download the form, review the included checklist of required supporting documents, which varies based on your individual circumstances. Do not mail your original foreign-language documents or passports. Instead, bring originals to your biometrics appointment and naturalization interview. Include certified English translations of any foreign-language documents in your mailed application.
The Civics Test and After Filing
All applicants filing on or after October 20, 2025, take the new 2025 civics test: 20 oral questions, with 12 correct answers required to pass. This applies to any N-400 filed from that date forward. After USCIS receives your mailed application, you'll receive an Account Acceptance Notice by mail instructing you to create an online account to track your case status and receive updates. Processing times vary, so check your account regularly for interview scheduling.