On Delta Air Lines in 2026, you can generally edit basic passenger information such as your contact details, SkyMiles number, and Known Traveler Number (TSA PreCheck) through the "My Trips" section of the website or Fly Delta app. However, significant changes like a legal name change due to marriage or a typo correction often require manual intervention from a reservations agent. You may need to provide legal documentation (like a marriage certificate) via a secure upload link or at the airport counter. For tickets booked through a third-party travel agency, you must typically contact the agency first to initiate these edits. It is a high-value "pro-tip" to verify your Secure Flight Passenger Data (full name, date of birth, and gender) at least 72 hours before departure to ensure it matches your government-issued ID exactly, preventing potential delays at the security checkpoint or boarding gate.