Lost an Expired Passport- Which direct.gov.uk form do I fill in?

Kavanne

If I try and fill in the one to renew it asks for passport no, which I don't have as my passport is lost. But I don't want to apply for my first adult one or ask for a replacement (costs £72!!). Which one should I fill in?

http://www.direct.gov.uk/en/TravelAndTransport/Passports/index.htm
Thanks for any input

EDIT: Hang on... even the lost passport form asks for the passport number.. how am I meant to remember this?!

Kavanne

Update: I just called them and I need to fill out an LS01 form, found that fine. Also an SE04 form... which I can't find. Can anyone assist me here?

KimYeovil

Don't you just send a 'lost passport' form in addition to the 'replacement' form?