[Symbiote]

My first UK passport was applied for using a paper form submitted at a local post office -- this was pre-widespread Internet. The person in the post office could advise that my photo met the technical requirements (size etc), but couldn't verify my identity.

The most recent renewal was done with an online system which produced a single page PDF declaration -- the rest of the data was only electronic. I printed it, attached my photos, signed and posted it. The new passport was delivered two days later.

You can see the application process: https://www.gov.uk/apply-renew-passport

I think the same applies for a driving license, but my first still has some years before expiry.