BRB is not and can not make the law,but,
Im not saying this as a de-facto method,
in fact Ive not yet had any issue getting paid for PIRs,
its just when a client asks me about certs I say, yes, your certificate will be in the post(or whatever) with your receipt.
never yet been an issue, and with landlords I usually have a verbal to rectify any immediate dangers during the test,
luckily for me I suppose Ive not had any major money issues with this so far,
its usually small things like a 7kw shower on 6mm with a 45A fuse cos Joe from the pub had a spare one, fancy chandelier fitting in bathroom, MEB hanging off gas cos a new meter fitted, or similar.
although recently I have got about