The kids are over 16, so they were applying for adult passports for the first time. We all sent our old passports, 2 pictures and one colour photocopy of proof of residency within the past year. I sent a copy of my ACR card and they sent their Uni ID’s.
As they are dual nationals we had to make a colour photocopy of their Philippine passport (every page including blank pages) as part of the application. Cost a blinking fortune!
No need to worry about counter signatures, as it’s not a requirement.
The application itself is £82 and the postage around £19. It used to be around £125 until last year.
Hope that helps.
Cheers