Is it possible to add frequent flyer number after booking?
If you have the booking code and your name, you should be able to sign into view the reservation and add the frequent flyer number. You can also have it added at check-in (online or in person) and sometimes even after the flight.
People Also Ask
Or you even forgot to add the number. Both things are not a problem, as all frequent flyer programs allow crediting miles retroactively. Depending on the program, you can credit the miles up to 12 months after the flight. Most programs, however, only allow this up to 6 months.
If you have the booking code and your name, you should be able to sign into view the reservation and add the frequent flyer number. You can also have it added at check-in (online or in person) and sometimes even after the flight.
In principle, these could vary at the level of each individual flight. In practice, when booking through an airline's website you'll simply be prompted for a single frequent flyer number, with the following effects: It will apply to all flights on the PNR. It will apply for both mileage earning and determining status.
While most airline and hotel points expire, there are a few exceptions. For example, points and miles within Best Western Rewards, Delta SkyMiles, Hawaiian Airlines HawaiianMiles, JetBlue TrueBlue, Southwest Rapid Rewards, United MileagePlus and Virgin Atlantic Flying Club don't expire.
It all depends on the frequent flyer program of your choice, its rules and flights, that you take, but the rule of thumb is, that with just 3-4 flights a year you can think about yourself as a frequent flyer, who's entitled to certain perks.