Changing a pre-booked seat
 

I will be flying BA to LHR in economy in May. I think I want to change the seat I pre-booked to another which is still free. Is it still possible to do that? I am not a frequent flyer at all.

Have you looked at the BA website for a tab that says "manage my booking" ? That should have your answer.

Usually websites have a "change your seat" option where you can go look at the map of the plane, same as you did when you first booked.

Yes, the "change your seat" option should be under "manage my booking" if the airline offers you that choice.

I tried those options. When I booked the seat I also paid a fee to get that seat, and it said I won't be able to change the seat until I check in for the flight if I still want to, bummer.

Maybe if you try to call the 800 number they can change it for you? Is there another or additional payment involved?

I bet if you called them they'd be happy to charge you again. Caveat emptor.