What to Do If You Made a Mistake on Form I-539
This article explains what to do after discovering an error on a mailed Form I-539: wait for the I-797C receipt with a receipt number, then contact USCIS customer service to correct minor errors, use InfoPass to book an appointment at a local office, write an explanatory letter if needed, or respond to a Request for Evidence. It notes that serious errors may lead to denial, requiring a new filing and fee, and that those whose legal status has expired must depart promptly.