Why should you get it done? well, recent government legislation; (always the way isn't it) anyhoo, a change to the health and safety laws recently means that the venue has become more responsible for the safety and wellbeing of the clients / patrons.
It's because of the possibility of legal action that IF, something goes wrong, then the burden of safety and quality lies with the attending performer.
Bands & DJ's are being turned away 'at the venue door' because they don't have a PAT test certificates for their equipment. This is happening in more and more venues, not just your Hotels like the Hilton, Raddisson, or Sheraton it's also the case at the Community hall (run by the local council )
if you have a faulty lead, or a slightly suspect piece of equipment, then how do you explain to the client that you "can't do the gig, 'cause your stuff's not up to scratch"??