About renewing passport when expired. Does section 3A and B have to be filled in?

If the latest old passport is the old blue one (pre 1993?) then you have to apply as a first time passport.

If the last passport was issued after 1993 and is undamaged then it is a renewal.

But you still have to return the old passport.

I think

I used the Post Office check and send service. Cost about £8 and got the new one back within a week. Worth every penny. Still have my old one too.