Just checked in online for BA09 to Bangkok tomorrow and got the following message

The travel document details you have entered are not valid for this flight

Before you go to the airport, please check the passport and visa requirements for your journey using the [IATA Travel Centre].

You will be unable to fly without the correct travel documents.

Unfortunately, our contact centre staff cannot help you resolve issues regarding passports and visas.


Our trip is for 21 days so no Visa needed and our passport details are all correct. I had checked twice when we booked it and also checked again on the IATA link above. We are taking internal flights (not on BA) then leaving from Singapore so is that anything to do with it?

Can anyone advise me as to what is going on as really stressed as to what it means and whether we will get on our flight tomorrow