Newb question

Assuming this is a standard usecase:
We need to allow a user to tell us the flight they will be on. Capture that information and then use it to check for updates on its status.
Do we need to just get the icao code of the airline + the flight number and date. And then use that information as the ident to search for updates?

Ident and date is not always sufficient because some airlines (for example Southwest Airlines) has multiple flights per day with the same ident.