What’s the Difference Between USCIS Form N-400 and N-600?

Finding your way safely through the U.S. immigration process can be overwhelming, especially when dealing with forms that look or sound similar. This confusion is widespread when people encounter USCIS Forms N-400 and N-600. Though they are both related to U.S. citizenship, these two forms serve very different purposes.

The main difference between N-400 and N-600 is this: Form N-400 is for people who want to become U.S. citizens through naturalization, while Form N-600 is for those who are already citizens but need an official certificate of citizenship. Filing the wrong form can cost you time, money, and even delay your ability to prove or obtain citizenship.

Understanding the Purpose of Form N-400

Form N-400, officially titled Application for Naturalization, is used by lawful permanent residents—commonly referred to as green card holders—who wish to become U.S. citizens. Naturalization is the process by which non-citizens voluntarily become full citizens of the United States. This form initiates that process.

Once your application is accepted, you’ll be invited to attend an interview, complete a civics and English test, and eventually take the Oath of Allegiance to become a citizen. Filing Form N-400 is a critical step for immigrants who want full legal rights, such as voting in federal elections, applying for a U.S. passport, or bringing certain family members to the U.S.

Who Should File Form N-600

Form N-600, called the Application for Certificate of Citizenship, is used by people who already have U.S. citizenship, usually acquired through their parents, but need documented proof. This is often the case for individuals born abroad to U.S. citizen parents or adopted children whose parents were U.S. citizens at the time of their adoption.

The form is not an application to become a citizen—it is only to confirm and document an existing citizenship status. This can be important when applying for a U.S. passport, enrolling in school, getting a job, or applying for public benefits that require citizenship documentation.

When to Use Form N-400

If you’re a lawful permanent resident and want to become a U.S. citizen, Form N-400 is your path forward. You can generally file this form after living in the U.S. for five years as a green card holder, or three years if you’re married to a U.S. citizen. You’ll also need to meet other requirements, such as good moral character, the ability to speak and understand English, and knowledge of U.S. civics.

Becoming a citizen through naturalization brings major advantages. You’ll gain full voting rights, more job opportunities, protection from deportation, and the ability to help your family immigrate more easily. If those are goals you care about, then Form N-400 is the right form for you.

When to Use Form N-600

Use Form N-600 if you were automatically granted U.S. citizenship as a child but need official documentation. This situation often applies to children born abroad to U.S. citizen parents or to children who U.S. citizens adopted before the age of 18. Even though these individuals are citizens by law, they don’t always have a certificate proving it.

This certificate can be extremely helpful—or even necessary—for legal and practical reasons. A Certificate of Citizenship may be required for obtaining a Social Security number, registering for school, or proving eligibility for federal benefits. Without it, you might run into difficulties proving your status, even if you are a citizen under the law.

Key Differences Between Form N-400 and Form N-600

To help you decide which form is right for your situation, here are the main differences between N-400 and N-600:

• Form N-400 is used to apply for U.S. citizenship through naturalization.
• Form N-600 is used to request a certificate that proves you’re already a citizen.
• N-400 applicants must meet residency and other eligibility requirements.
• N-600 applicants must already qualify as U.S. citizens under existing laws.
• N-400 includes interviews and testing; N-600 does not require a test.
• N-400 leads to a new citizenship status; N-600 confirms an existing one.

Fees and Processing for N-400 and N-600

Filing fees for these forms are expensive, so it’s important to understand the costs involved before applying. As of now, the filing fee for Form N-400 is $640, with an additional $85 biometrics fee, totaling $725. Biometrics include fingerprinting and photographing to verify your identity.

For most applicants, Form N-600 comes with a $1,170 filing fee. Note that most fees are non-refundable, even if your application is denied, so be sure you’re using the right form before you file.

Documentation and Proof Requirements

When you file Form N-400, you’ll need to provide various documents such as your green card (Form I-551), evidence of marital status if applying under the 3-year rule, and records of any criminal history or legal issues. These documents help prove your eligibility for naturalization.

For Form N-600, you will need to submit documents that prove your claim to citizenship. Typical proof includes your birth certificate, your parents’ citizenship documents, and evidence of your parents’ physical presence in the U.S. before your birth. Providing accurate and complete documentation is important for both forms, as missing or incorrect paperwork can delay your application or lead to denial.

Need Help Applying for Citizenship or Requesting Your Certificate?

Visit FileRight.com for user-friendly tools, lawyer-reviewed application prep, and filing support that helps ensure your paperwork is complete and accurate. Should you need to speak directly with an immigration attorney, we can help solve your issues and achieve your immigration goals.