Yes, you typically receive your frequent flyer miles only after the flight has been completed. While your booking might show an "estimated miles" figure, the actual points are not deposited into your account until the airline's system confirms you were actually on the plane (or "flown"). In 2026, most major carriers like Delta and United deposit miles within 24 to 48 hours of landing. However, if you are flying with a partner airline (e.g., flying Lufthansa but earning United miles), it can take anywhere from 7 to 30 days for the systems to sync. If your miles haven't appeared after two weeks, you should keep your boarding pass and ticket number to file a "missing mileage" claim through the airline's website.