Figuring out how to get US citizenship for your children can be one of the most confusing parts of the immigration process. You might have heard of Form N-400, the standard application for naturalization. But then you hear about Form N-600, the Application for Certificate of Citizenship.
Which one do you need? The answer depends entirely on your child’s age and how you, the parent, obtained your citizenship.
Choosing the wrong form can cost you over a thousand dollars in non-refundable government fees and months of lost time. This guide will break down the differences between N-600 vs N-400 simply, so you can move forward with confidence.
ℹ️ Key Takeaways
- Form N-400 is for “Naturalization.” It is for Green Card holders over 18 who want to become citizens.
- Form N-600 is for “Recognition.” It is for children (often under 18, but sometimes adults) who automatically became citizens through their parents and just need proof.
- You cannot use N-400 for a child under 18.
- If your child is a Green Card holder living with you, and you become a citizen before they turn 18, they likely need Form N-600.
The Core Difference: Asking vs. Proving
To understand which form to use, you have to understand the legal difference between “becoming” a citizen and “being” a citizen.
Form N-400 (Application for Naturalization) is a request. You are asking the US government to grant you citizenship. You are saying, “I have been a permanent resident for 5 years, I have good moral character, and I want to become an American.”
Form N-600 (Application for Certificate of Citizenship) is a claim. You are telling the US government, “According to the law, I am already a citizen because of my parents. Please give me the paper that proves it.”
The “Magic Number”: Age 18
In US immigration law regarding children, 18 is the cutoff age.
- Under 18: Children generally cannot apply for naturalization on their own. They usually obtain citizenship automatically through their parents.
- Over 18: Individuals must apply for naturalization on their own merits, just like any other adult.
Form N-600: For Children Who “Derive” Citizenship
Most parents searching for this topic will need Form N-600. This form is used when a child automatically becomes a citizen by operation of law. This is called Derivative Citizenship.
Your child may need Form N-600 if:
- You are a US Citizen: Either by birth or naturalization.
- The Child is Under 18: The child was under 18 when you became a citizen.
- The Child has a Green Card: The child is a Lawful Permanent Resident.
- The Child Lives with You: You have legal and physical custody of the child in the US.
If all these things are true at the same time, your child likely became a US citizen the moment the last condition was met. They don’t need to “apply” to become a citizen—they are one. However, they have no proof. Their Green Card is technically invalid now because they are citizens, but they don’t have a passport or certificate yet.
This is where Form N-600 comes in. It asks USCIS to look at the facts and issue a Certificate of Citizenship.
💡 Pro Tip
You can also apply for a US passport for your child at the post office using the same evidence (parent’s naturalization certificate, child’s Green Card, birth certificate). A passport is cheaper than Form N-600. However, many parents prefer to file Form N-600 to get the Certificate of Citizenship because it never expires, whereas a passport must be renewed every 5-10 years.
Form N-400: For Children Who Turn 18
If your child does not meet the requirements for automatic citizenship before their 18th birthday, they cannot file Form N-600. They have “aged out” of the automatic process.
In this case, your child is treated as an adult permanent resident. To become a citizen, they must wait until they are 18 years old and file Form N-400.
Your child needs Form N-400 if:
- They are currently over 18.
- They have held their Green Card for at least 5 years (or 3 years if married to a US citizen, though this is rare for young adults).
- They did not automatically acquire citizenship from you before they turned 18 (perhaps you naturalized after they turned 18, or they were living outside the US).
Example Scenario
Maria and her son, Luis: Maria becomes a US citizen when Luis is 16. Luis has a Green Card and lives with Maria.
- Result: Luis automatically becomes a citizen at age 16.
- Form Needed: Form N-600 (to get his certificate).
Jorge and his daughter, Elena: Jorge becomes a US citizen when Elena is 19. Elena has a Green Card and lives with Jorge.
- Result: Elena was over 18 when Jorge naturalized. She did not become a citizen automatically.
- Form Needed: Form N-400 (she must apply for herself).
Cost and Processing Comparison
The costs and timelines for these forms are quite different.
Form N-600 (Certificate of Citizenship)
- Purpose: Proving existing citizenship.
- Filing Fee: The fee is often higher than the naturalization fee (check current fees on USCIS.gov, but it is typically over $1,100).
- Interview: Often waived for children, but sometimes required.
- Test: No Civics or English test required.
- Processing Time: Variable, but often comparable to N-400.
Form N-400 (Naturalization)
- Purpose: Applying for new citizenship.
- Filing Fee: $760 (includes biometrics).
- Interview: Mandatory.
- Test: Mandatory Civics and English exam (unless a medical waiver applies).
- Processing Time: 8–14 months on average.
⚠️ Warning
The filing fees for USCIS forms are non-refundable. If you file Form N-600 for a child who is not actually a citizen, USCIS will deny the case and keep the money. If you file Form N-400 for a child under 18, they will reject it and keep the money. Always double-check eligibility before sending payment.
Can a Step-Child Use Form N-600?
This is a very common point of confusion.
Under current immigration law, step-children do not benefit from the automatic citizenship provisions that biological or adopted children do.
If you are a US citizen step-parent, and your step-child has a Green Card, they do not automatically become a citizen when you naturalize. They must wait until they are 18 and file Form N-400 on their own.
Exception: If you legally adopt your step-child before they turn 16 (and meet other custody requirements), they may be treated as your child for immigration purposes and could qualify for Form N-600.
Detailed Breakdown: How to Decide
If you are still unsure, follow this simple decision logic.
Question 1: Is the child currently under 18?
- Yes: They cannot file N-400. You must determine if they are already a citizen. If you (the parent) are a citizen, the child lives with you, and has a Green Card, they are likely citizens. File Form N-600.
- No (Over 18): Go to Question 2.
Question 2: Did the child meet the citizenship requirements BEFORE turning 18?
- Yes: Even though they are now an adult (e.g., 25 years old), if they automatically became a citizen back when they were 16, they are still a citizen today. File Form N-600. You are never “too old” to file N-600 if the citizenship happened automatically in the past.
- No: If you naturalized after they turned 18, or they got their Green Card after 18, they are not citizens yet. They must file Form N-400.
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Common Mistakes to Avoid
1. Waiting too long to get proof
While you can file Form N-600 at any time, it is much easier to do it while the child is still young. If you wait until they are 30, it might be harder to find evidence that you had legal custody of them when they were 15.
2. Assuming a Green Card is enough
Children with Green Cards must renew them every 10 years. If your child is actually a citizen, they shouldn’t be renewing a Green Card—they should have a passport or Certificate of Citizenship. Green Card renewals are expensive and unnecessary for citizens.
3. Filing N-400 for a 17-year-old
Parents often try to “get a head start” by filing N-400 when the child is 17 so it’s ready by 18. Do not do this. You must be 18 on the day you sign and file the Form N-400. If you file one day early, it will be rejected.
How Greenbroad Helps
Immigration forms are dense and the instructions can be confusing. For Form N-600 specifically, you need to prove the parent’s citizenship, the child’s birth, the child’s residence, and legal custody. Missing one document can lead to a Request for Evidence (RFE) or a denial.
Greenbroad is a document preparation service designed to make this easy. We are not a law firm, but we combine smart technology with human review to ensure your application is complete.
Our $749 package includes:
- A comprehensive eligibility check.
- Preparation of Form N-600 or N-400.
- A customized checklist of required documents (birth certificates, custody decrees, etc.).
- Detailed filing instructions so you know exactly where to mail your package.
We take the stress out of the paperwork so you can focus on your family’s future.
Conclusion
The choice between N-600 and N-400 comes down to one simple concept: Recognition vs. Application.
If your child is already a citizen by law, you want recognition (Form N-600). If your child is an adult Green Card holder who wants to become a citizen, they need to make an application (Form N-400).
Don’t let the paperwork delay your child’s ability to claim their rights as an American citizen. Whether it’s applying for a US passport, voting (for those over 18), or simply having the peace of mind that their status is secure, getting the right documentation is essential.
If you are ready to secure your child’s citizenship proof without paying thousands in legal fees, we are here to help.
🚀 Get Your Application Started
Ready to file Form N-600 or N-400? Let Greenbroad handle the forms and organization for you.
Book a call today to confirm your eligibility and start the process.
For more information on the official requirements, please refer to the USCIS Form N-600 page.
Disclaimer: Greenbroad is not a law firm and does not provide legal advice. We are a document preparation service. If your case involves complex legal issues, criminal history, or custody disputes, you may need to consult an attorney.
Frequently Asked Questions
Can I file Form N-400 for my child who is under 18? No, minors generally cannot file Form N-400 to naturalize on their own. If they have a Green Card and you become a citizen before they turn 18, they typically acquire citizenship automatically and should file Form N-600 instead.
Which form is cheaper, N-600 or N-400? Form N-400 currently has a lower filing fee than Form N-600. However, you cannot choose which form to file based on price; you must file the form that legally applies to your child’s specific status and age.
What happens if my child turns 18 while the N-600 is pending? For Form N-600, eligibility is frozen at the moment all conditions were met, usually before the child turned 18. As long as the requirements were fulfilled before their 18th birthday, they can receive a Certificate of Citizenship even if the application is approved after they become an adult.
Does a US passport serve the same purpose as a Certificate of Citizenship? A US passport is proof of citizenship, but it expires and is primarily a travel document. A Certificate of Citizenship obtained via Form N-600 never expires and serves as permanent, primary evidence of your child’s status within the United States.
Do step-children automatically become citizens when a step-parent naturalizes? Generally, step-children do not automatically derive citizenship through a step-parent’s naturalization unless they were legally adopted. Step-children usually must wait until they are 18 to apply for naturalization on their own using Form N-400.