I had to provide all the normal proofs to work and my SIA licence, due to the role and certain sites I could be working on, I also had to go through a background check as well. My interview was brief approx 15-20 minutes and was carried out by one of the area managers. The manager took note that out of 5 interviewees that day I was the only one who had arrived on time, this was a key thing they wanted to know to see if people would be reliable, and I was told that this was one of the manin things that meant I got offered a job before anyone else interviewed that day.