After you’ve filed almost any application or petition with U.S. Citizenship and Immigration Services (USCIS), they will respond by mailing you a Form I-797C, Notice of Action, within approximately 1-3 weeks. (It may take longer to receive the I-797C for some other forms like Form I-751.) The I-797C, Notice of Action, is commonly known as a receipt letter.
For applicants who have incorrectly filed or included the wrong payment, the receipt letter will indicate that USCIS has rejected your case. You will need to refile. If you’ve prepared the form correctly and followed the USCIS directions carefully, the receipt letter will indicate that USCIS has accepted your case. Once the form has been accepted, USCIS will begin reviewing your case.
The receipt letter contains a unique 13-digit receipt number. Also known as a case number, it’s a very important number to help you track the progress of your case or identify a particular immigration filing.