Sorry for thread resurrection, but this seems as good a place as any for someone searching for the answer to this. Just had my "annual" Napit assessment this morning (previous one in 2021), and can offer the following as a bit of a brain dump:
- most of the notifiable jobs I did, I didn't tick the box that said "I consent to using this job for assessment". There were no issues with not consenting to anything in advance.
- the assessor contacted me a week ago by email, with a list of things he needed to see, including 3 addresses. The requirement was "2 new circuits". A board change on its own is not sufficient, although a board change with some other work (additions and alterations) would probably be ok.
- he was happy to see whichever one I suggested, particularly as it was close, and the most interesting one.
- I had prepped the customer for this chosen job about the possibility of assessment in the future, at the time I was doing the job (a few months ago), and when I booked the date in (a month or two ago), asked him to agree to let me and the assessor on site. As a sweetner, I always offer my client an hour or two of free labour as a thank you for agreeing to use their job in the assessment... I figure they're giving up part of a morning for us to do our thing, I can give the same back as a thank you. Also, I say that it's actually a good thing that my work is being checked, gives them more peace of mind.
- I asked the clients of the other two "backup jobs" if we could potentially come round, but stressed it was very unlikely that we actually would. As soon as my assessor confirmed the job we'd be seeing, I let them know we weren't coming round.
- the multi-choice technical questions were in 2 parts - one on the Wiring Regs, the other on the Building Regs. The first set are basically like a mini "18th Edition" exam (C&G 2382), with a couple of questions from Part 7, one from Appendix 4, and the others from the main bit of the Regs. The Building Regs questions were harder, as most were from parts other than Part P - a couple of questions from Part A (structure), one each from Parts F (ventillation), L (fuel and power), and M (access to and use of buildings). Although one of the questions I could answer from "The Electrician's Guide to the Building Regs" book (about depth of chases), the other ones I had to actually go into the Approved Documents to find the answers. So although they ask that you have access to the Part P Approved Doc, you're gonna need access to the other parts as well to answer the questions.
- one thing he didn't ask for in advance, but wanted to see, was evidence of CPD (continual professional development). I was able to do it verbally and there were no issues, but he said that the way things are going, they are more likely to ask for a log of this in the future - short description of what it was, e.g. article in Professional Electrician / talk at Elex / online discussion on Electrician's Forum / looking up datasheets for a job / technical enquiry with Wylex or whoever... what it was about, and roughly how long. He indicated that on average, over the year, about an hour a month (or more) is about right. He was happy this year to just have a discussion, but I'll start making a note of stuff in the future, to show at a future assessment.
- always offer coffee and biscuits, and always have paperwork ready. This is the main thing.
I have seen that tick box but never tick it, may not be suitable when the time comes depending on customer, imagine going back to a 2 year old job for a customer you may not have worked for since, just weird 
