The receipt situation, at least for me has gone like this:
Initially "receipt for everything". This was recognised as being unworkable/stupid so was changed to "No receipts for stuff under £5". This has now been changed to "receipt for everything, but if you cant get one then self certify". This seems very sensible and note the £5 thing no longer exists.
I got the impression that this was to be the same everywhere, but there do seem to be a lot of local procedures/local forms popping up.