Form N-400: Documents, Cost, Eligibility and Timeline

Form N-400 is issued by USCIS for Green Cardholders applying for U.S. citizenship. Also known as the Application for Naturalisation, it is the first step for a green card holder to apply for U.S. citizenship. This process has specific eligibility criteria, and once you meet them, you must submit Form N-400 to USCIS. After that, you can officially apply for U.S. citizenship.

Read this blog to know more about the N-400 timeline, required documents, cost and eligibility criteria.

Quick Link: N400 Application PDF

What is the N-400 Application Process?

Follow the steps below to file Form N-400.

1. Check your eligibility, including age, residency, and good moral character requirements.
2. Gather the required documents and review the latest USCIS requirements.
3. Complete and submit Form N-400 online or by mail.
4. Attend your biometric appointment for fingerprints and photographs.
5. Complete the USCIS interview and citizenship test.
6. Wait for USCIS to review your application and issue a decision.
7. If approved, attend the Oath of Allegiance ceremony and become a U.S. citizen.

Is it Possible to file Form N-400 Online?

Yes, you can file Form N-400 online. But if you are applying for a fee reduction or waiver, you must fill out the N-400 form manually and file it by mail. To apply online, you must first create an online account with the USCIS. You must sign your application electronically by typing your full name at the end.

What are the N-400 Eligibility Criteria?

The eligibility criteria include:

• You must be at least 18 years old and must have a Green Card for 5 years (3 years if you are married to a US resident)
• You must have meet the eligibility requirements for the naturalisation process.

How Long is Form N-400 Taking to Process?

The current processing time for N-400 is roughly 5.5 months. Since 2019, USCIS has prioritised naturalisation applications and has cut the N-400 processing time in half. Usually, the processing speed depends on the USCIS field office that handles the applications. Some applicants might even get a head start on this process.

Form N-400 Timeline 2026

The table below outlines the total time taken for the naturalisation process.

What are the Documents Required for Form N-400?

Before applying for U.S. citizenship with Form N-400, you must possess a few necessary documents as evidence proving you are eligible for the naturalisation process. 

The USCIS requires the following documents:

• Proof of Residency
  1. Green card photocopy (Permanent Resident Card) alongside Form I-551.
  2. If your Green Card is lost, you must include a photocopy of the Form I-90 receipt.
• Fee Payment Method
  1. Submit check or money order with your A-Number on the back.
  2. You can also use a Credit Card. (Form G-1450)
• Recent photographs (if residing outside the US)
  1. Two identical colour photos in accordance with USCIS guidelines.
  2. On the backside of each photo, write your name and A-Number lightly using a pencil.
  3. For identification, make sure your face is clearly visible.

Are there any Additional Supporting Documents for Form N-400?

Yes. Depending on the situation, some individuals might need to provide additional supporting documents for the N-400. These include:

• The name is different from what is on the Green card
  1. Marriage certificate, divorce decree or court documents showing the name change.
• Application based on marriage to a U.S. Citizen
  1. Evidence that your spouse has been a US citizen for the last 3 years.
  2. Evidence of your marital status, such as marriage certificates
  3. Photocopy of divorce papers, annulment papers or death certificate (if you were previously married)
  4. Documents related to you and your spouse, such as shared tax returns, bank statements or rental agreements
  5. Official joint tax returns from the past 3 years
  6. IRS records of tax filings for the last 3 years
• If you serve in the US military and are applying for citizenship based on your service, you must include Form N-426
• If you are not in the US for 6 months or more, you must provide evidence that you kept ties to the US (such as tax returns or bank mortgages)
• If you are applying for an exemption to the US citizenship test based on a qualifying medical condition, then you must file Form N-648.

How Long Should I wait to Apply for Citizenship After Getting a Green Card?

In most cases, if the applicant is not a U.S. resident, they must live in the U.S. as a lawful permanent resident for at least 5 years. If they are married to a U.S. citizen, then they must be a U.S. resident for only 3 years. According to USCIS data, the average time for marriage before applying for U.S. citizenship is 7 years.

What is the 90-day Early Filing Rule for Naturalisation?

If you have been a Green Card holder for the specified duration, you can file your naturalisation application 90 days early.

To figure out your earliest filing date, follow the steps below.

• Find the issue date on your Green Card.
• Add 3 or 5 years (based on your eligibility category) to determine your naturalization eligibility date.
• Subtract 90 days from that date to find the earliest date you can file Form N-400.

Example:
Green Card issued: January 1, 2025
+ 5 years = January 1, 2030 (Eligibility Date)
− 90 days = October 3, 2029 (Earliest N-400 filing date)

What is the N-400 Cost?

The government fee for filing Form N-400 is $760. There are also additional costs to consider, such as application assistance, translation services, photocopying and mailing costs and the potential reapplication cost if your application is denied. Certain applicants are eligible for a fee reduction or waiver.

Where to Send the Filled N-400 Form?

This usually depends on whether you are filing the form online or by mail. If you are filing by mail, the USCIS address you will send the mail to depends on the state where you live. It also depends on the delivery service you choose.

If you are applying based on military service, you must send your N-400 materials to a special address, and it depends on the delivery method you choose. USCIS provides a list of addresses to which applicants must submit their N-400.

Important Tips to Remember

Avoid common mistakes and keep your N-400 application for a smooth N-400 filing process.

Use Black Ink Only

• Complete the form electronically if possible.
• If filling by hand, use black ink only.

Review Your Form Before Filing

• Ensure all information is accurate and complete.
• Include all required supporting documents.
• Double-check your application to avoid delays or denial.

Provide Translations

• Submit certified English translations for any non-English documents.

Keep the Form Clean

• Avoid cross-outs, highlights, or writing outside designated spaces.
• Use a new form if major corrections are needed.

Submit Only Required Documents

• Follow USCIS instructions on which documents to submit.
• Avoid sending unnecessary original documents.

Don't Forget to Sign

• Sign the N-400 form before submission.
• Missing signatures can result in rejection.

Conclusion

To file the N-400 form, you must first understand the N-400 eligibility criteria and its required documents. To make the filing process simpler and reduce delays, you must prepare the application carefully, meet all the naturalisation requirements and submit the necessary documents. With proper planning and attention to detail, the applicants can move forward on their journey to becoming U.S. citizens.