US Citizenship Application (Form N-400) – Fillable PDF

Welcome to your one‑stop destination for the US citizenship application (Form N-400). This page provides the official fillable PDF, step‑by‑step instructions, and tips to ensure a smooth filing process.

What Is Form N-400?

Form N-400, Application for Naturalization, is the United States Citizenship and Immigration Services (USCIS) form used by permanent residents to apply for U.S. citizenship. The form collects personal information, residence history, employment, travel, and moral character details.

How to Fill Out the N-400 Online with Formize

Instead of downloading the PDF and opening a separate editor, simply click the "Fill out this form" button below. The Formize PDF Filler app will load directly in your browser, letting you complete every field online.

Common Mistakes to Avoid

• Leaving sections blank: Even optional fields must be answered with "N/A" if they do not apply.
• Mismatched dates: Ensure dates on the residency and travel sections are consistent with your passport.
• Signature errors: Use the electronic signature tool; a handwritten signature on a printed copy will be rejected.
• Incorrect filing fee: Verify the current fee on the USCIS website before submission.

Where to Submit Your Application

After completing the form, download the filled PDF and submit it through one of the following USCIS channels:

• Online via USCIS myAccount
• Mail to the address listed in the Form N-400 Instructions
• In person at a USCIS Field Office (appointment required)

Need More Help?

Review the official USCIS instructions linked at the bottom of the form, and double‑check your answers before filing. If you have questions about eligibility, consider consulting an immigration attorney.