In the Memo or "For" section, write "USCIS I-765" and your SEVIS ID number, found in the in the upper left-hand corner of your I-20. A filing fee is required for many immigration forms.If you do not submit the correct fee, we will reject your form. To fill out the money order, you will need to "Pay to" U.S. Department of Homeland Security. You can find stepbystep instructions in the Immigrant Fee Payment Guide. Children who regularly reside outside the United States may use Form N600K to apply for citizenship based on a US citizen parent. The receipt number is the unique case number the USCIS assigns to each applicant after receiving their petition. Decide on the money order amount. It's best to download the form just before mailing the application since USCIS updates it frequently. How to fill out Form I-765.