Travelling to Spain, I'm sure I should be giving my passport details when I book my flights?

[ihatethecold]

When I went to Barcelona 2 years ago I'm sure I had to give those details when I booked my flights, or have I imagined it?

Anybody know if I still have to do this?

I think you are talking about Advance Passenger Information. Yes, you do have to give your passport details, and those of all other passengers in your family/group travelling together.

There should be a facility for doing this on the airline website.

Thanks, I wasn't asked when I booked, I will have a look though.