Home > U.S. CITIZENSHIP > Step-by-Step Instruction on filling in n-400


If you have a Green Card (meaning you are a lawful permanent resident of the United States) and you qualify to apply for U.S. citizenship, you can do so by completing United States Citizenship and Immigration Services (USCIS) Form N-400, Application for Naturalization. This a long form, which consists of 20 pages and 18 parts, each of which includes multiple questions or blanks to fill out, and your application won’t be processed unless all of them must be filled out (note that some areas should be left blank until the day of your interview). You should also be aware that leaving any other part blank or answering any questions incorrectly or untruthfully, could result in the denial of your application. To complete Form N-400 correctly, make sure you have certain documents including your Permanent Resident Card, passport, birth certificates, marriage certificates, divorce decrees, and any other documents that can be used to verify important dates and events.


Form N-400 is used by permanent residents (Green Card holders)  who want to become U.S. citizens.  If you belong to one of the following group, you may qualify to file this form with USCIS :

  1.  A five-year permanent resident. See details here.
  2.  A permanent resident currently married to and living with the same U.S. citizen for three years. See details here.
  3.  A member of the U.S. Armed Forces (or honorably discharged in the past six months) who served for a minimum of one year.


All our eligibility quizzes are prepared by experienced immigration attorneys and are easy to use and understand. It only takes several minutes to complete a quiz and find out if you all eligible to apply. If you pass the quiz we will automatically choose all required forms for your immigration case

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Suitable for one of 3 categories? If yes, we congratulate you and you can safely move on in step 2


As we have already noted, this is a long-form, so don’t rush. Be sure to use black ink to write your answers if you are completing this form in pen. If you make a mistake, do not try to erase it, cross it out, or rewrite your answer; simply start over on a new form.

Be aware that some sections, especially Parts 5, 8, and 11, have limited space for your answers.  If you have additional room for your responses, you can use separate sheets of paper. However, you must write your A-Number at the top of that paper, along with the Page, Part, and Item Number to which your answer refers.

Now, To make sure that you understand each section, let’s review each step one by one:

Part 1.

This is where you should write your Alien Registration Number (A-Number) and select the box that best applies to your qualifications for U.S. citizenship.

Part 2.

This is where you provide the legal name you are currently using and your name exactly as it appears on your Green Card. You should also provide any other names you have ever used. You can change your name if you want to when applying for U.S. citizenship. There is space to write your new chosen name in question 4 of Part 2. The additional information required in this section includes your Social Security number, date of birth, country where you were born, and your nationality.  This is the section in which you will also answer questions about any disability you might have and any English language test exemptions you may qualify for.

Part 3.

If you need any special arrangements, this is where you request them by checking the box that applies to you.

Part 4.

This is where you print your contact information, including your home address, mailing address, phone number(s), and email address in the space provided.

Part 5.

Here, USCIS wants information about all of the places where you have lived in the past five years. Begin with your current address (where you live and get mail) and then provide any others.

Part 6.

This is where USCIS wants you to provide information about your parents.

Part 7.

In this part, the information you provide will be used for a background check. Print provides accurate details about your ethnicity, your race, your height and weight, and your eye and hair color.

Part 8.

This is where you should provide information about your employment and education. USCIS only wants details about the jobs you have had and places you have gone to school in the past five years, including police or military service. Print the name of the employer or school, the complete address, dates of attendance, and your duties with that employer. Write “unemployed” if you didn’t have a job for any part of that time.

Part 9.

In this part, USCIS wants you to answer questions about the time you have spent outside the U.S., including how many times you traveled abroad, for how many days, and where you went. Be sure to be specific.

Part 10.

The questions in this part pertain to your marital history. For question 1, if you answer “Single, Never Married,” you proceed to Part 11.

Part 11.

This is where you should provide information about your children. Start by listing how many children you have, regardless of their age(s), living with you or not, born out of wedlock, adopted, or if they are living or deceased.

Part 12.

In this part, your answers will help the USCIS officer determine if you are a person of good moral character. Although you may be tempted to do otherwise, be honest. Failure to do so may have serious consequences.

Part 13.

This is the part in which you should provide a statement about how the form was filled out (either by yourself or with assistance from an interpreter). You must also certify that the supporting documents you submit are true copies of the original documents and authorize the release of information about you to USCIS by any agencies necessary to verify your eligibility to become a U.S. citizen. You will complete Part 13 by signing your name and writing the date in the spaces provided.

Part 14.

In this section, provide information about the interpreter who helped you fill out Form N-400 (if any), including their name and contact information. At the end of Part 14, the interpreter (if any) must certify his or her credentials and sign and date in the spaces provided.


If someone else prepared your N-400, you will provide information about that person in Part 15. USCIS needs this person’s name, address, and contact information. The preparer must also make a statement and certification about their qualifications and intent in filling out the form for you. The preparer should sign and date in the space provided.


– Do NOT complete Part 16 until you are told to do so by the USCIS officer at your interview. When you are instructed to do so, you will sign and date the form in the space provided. By doing so, you swear that all information you have provided is true and accurate.

– Do NOT complete Part 17 until the USCIS officer tells you to do so. If you have, or ever had, an order of nobility or a hereditary title (if you were a prince, princess, count, duke, etc.) in any foreign country, you will be asked to renounce those birthrights to apply for U.S. citizenship. You must sign and date this section, as well.

– Do NOT complete Part 18 until the USCIS officer tells you to do so at your interview. In this part, you promise to take the Oath of Allegiance as part of becoming a U.S. citizen. Once you are instructed to do so, you will print your full name, sign, and date in the spaces provided.











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All applicants for U.S. citizenship must provide certain documents with Form N-400. These are:

  • A photocopy of both sides of your Permanent Resident Card,
  • Two identical passport-style color pictures of yourself that meet the specifications set forth in the instructions for Form N-400, and
  • A birth certificate for each of your child(ren), if you have any.

If you are applying for naturalization based on marriage, you must also include:

  • A copy of the passport or naturalization certificate proving your husband or wife has been a U.S. citizen for at least three years,
  • Your current marriage certificate,
  • Any prior divorce decrees (if you’ve been married before),
  • IRS income tax returns from the past three years,
  • Utility bills from the past three months (both spouse’s names must be on them), and
  • Joint bank statements for the past three months

If you have ever been detained or arrested by any law enforcement agency, and you were not charged, you must also include:

  • The original statement from the arresting agency or applicant court verifying that no charges were filed.


Once you fill out your immigration form(s) our system will generate a customized checklist of documents you will need to submit to the USCIS with your immigration case. You can easily upload your documents into our system and request an attorney review to ensure that they are accurate and sufficient

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Now your form is completed correctly and it’s time to send it to USCIS


Along with your completed Form N-400,  you must include your supporting documents, payment for applicable filing fees (ranging from $680- $595) and the $85 biometric service fee. Please note that you do not have to pay the biometric services fee if you are 75 or older, or if you are filing under military provisions.  To pay the applicable fees, use a check drawn on a U.S. account and made out to the Department of Homeland Security. If you want to use a credit card, you must also submit the G-1450 authorization form.


For all domestic applicants filing  Form N-400 by mail:  The correct mailing address depends on your U.S. residence.  For detailed mailing instructions please visit the Direct filing addresses for form N-400 page.

If you are a current or former member of the military, a spouse of a member of the military, or a close family member of a deceased member of the military, send your application to:

USCIS, P.O. Box 4446, Chicago, IL 60680-4446


Once your forms and documents are complete and ready to be filed you will be provided with detailed instructions on where to file and what to expect after your case is filed with the USCIS

The most detailed instructions with examples

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