Call your chosen airline's frequent flyer mile program number, which is listed on your frequent flyer mile card or membership account. Explain to a representative that you recently completed a flight but forgot to register your frequent flyer number to receive points. Provide the flight number, date and destinations. The representative will verify your presence on that flight and award the miles to your account.
Visit the website of the airline on which you are a frequent flyer member; log into your frequent flyer miles account and locate the "Request Flyer Mileage Credit" form.
Complete the form and submit it to your airline to receive credit for your flight. You must include your flight number, the date of your flight and your confirmation number.
