N-400 Application For Naturalization

The N-400, Application for Naturalization is a form used to apply for U.S. citizenship. Form N400 is also known as the naturalization or citizenship application. It is submitted to U.S. Citizenship and Immigration Services (USCIS). 

Naturalization is the process of becoming a citizen for people not born in the United States who are lawful permanent residents.

How to prepare

1. Make sure you are eligible to apply to become a U.S. citizen and that your green card is valid.

2. Read the instructions carefully.

3. Collect all the requested documents so you can refer to them as you complete your application.

4. Decide if you need legal help. It is a long complicated form. Speaking with a lawyer is recommended. There are organizations that offer free help, such as Citizenshipworks.  

5. Learn the meaning of hard words and terms used in Form N-400.

Fill out Form N-400

You will first need to choose if you are going to file the application online or by mail.

If you are filling the form out online, you will need to set up an account on the USCIS website. You can work on the application at your own pace and save it as a draft online until you are ready to submit it. Find more instructions in this video:

(https://youtu.be/sl5HbkUAVh4)

If you are mailing in your application, you can use the PDF of Form N-400 and either:

  1. Download it and type in your answers.
  2. Print it and write in your answers. 

Tips for filling out your N-400:

  • Your name should match your green card.
  • A-number must be at top of every page. 
  • Answer every question on the form.
    • Write “N/A” for not applicable if the question does not relate to you.
    • Write “none” for answers with zero.
  • Answer each question truthfully.
  • If you do not know the answer to a question, explain why.
  • Ask someone to review all your answers.
  • If you are using a paper application:
    • do not use a highlighter or whiteout.
    • If you make a mistake, start over.
    • Don’t forget to sign the application!
    • Save a copy of it completed.
If you lie or misrepresent information on your application, there can be severe consequences. You can be charged with a crime, lose your ability to ever become a citizen, or even be deported. Your answers will be compared to previous documents, including overseas interviews and tax filings.

Form N-400 sections

The form is split up into 18 parts. Each section asks you questions about different things.

Part 1: eligibility
Part 2: you (name, date of birth, etc)
Part 3: disability & accommodations
Part 4: contact information
Part 5: residence
Part 6: parents
Part 7: biographic information (race, etc)
Part 8: work & school (past 5 years)
Part 9: trips abroad (past 5 years)
Part 10: marital history
Part 11: children
Part 12: legal, threat & criminal review
Part 13: certification & signature
Part 14-15: preparer & interpreter information
Part 16-18: completed at interview

Learn the meanings of hard words and terms

It is important to understand the words on Form N-400. It will help you fill out the form correctly. It will also help you prepare for the naturalization interview when you will be asked about your answers in the application.

File Form N-400

Information varies depending on whether you are submitting it online or by mail.

If you are submitting online, you can upload photos of all the requested documents from your computer, phone, or tablet. You will be directed through the process and given an opportunity to review your answers first. You will provide an electronic signature before being directed to provide payment.  

If you are submitting by mail, you should send photocopies of the requested documents unless an original was requested. Originals will be returned to you. Include the citizenship filing fee. Review the USCIS filing tips and look up your USCIS lockbox address for where to send it to. 

Things to note about requested documents:

  • All documents in another language must be translated into English by a certified translator. 
  • If you are seeking a disability exemption, include Form N-648
  • If you live outside the U.S., you must send 2 passport-style photos.

What happens after filing

If you submitted online, you can log in to your USCIS account to view your receipt number and case status.

If you submitted by mail, USCIS will mail you a receipt notice after they receive your application. You can check the status of your application online by typing in your receipt number.

You will also get a notice for your biometrics appointment to have your fingerprints and photograph taken. USCIS will schedule your naturalization interview after reviewing your background check. 

If you change your address after applying, you must notify USCIS within 10 days. You can change your address online. Changing your address with the post office will NOT change your address with USCIS. If you miss an appointment because the notice went to the wrong address, you could have your application denied or have to wait longer.

Next: Learn what to expect at the naturalization interview and test


The information on this page comes from trusted sources, including USA.gov and USCIS.gov. We aim to offer information in plain language that is easy to understand and updated regularly. This page is for guidance. USAHello does not give legal advice, nor are any of our materials intended to be taken as legal advice.