First identify the incorrect field and establish the correct information. Do not assume that a submitted form can simply be edited or that a new application will automatically replace the number linked to your appointment. Check the Department of State's DS-160 guidance and the current instructions of the embassy or consulate handling your application. If a replacement form is needed, verify how its barcode should be associated with the appointment. Keep relevant confirmation pages securely and follow directions about which to present. Prepare an accurate explanation rather than attempting to conceal the discrepancy.