I work for 3 companies mostly commercial, and a little domestic. So i have not needed to be a member myself.
This year i did join the gang so i could do more private jobs and set myself up in case the commercial drys up.
I spoke to NIC and was told i needed a notifiable and non notifiable. I did Just that, rung them to book it in and was told i needed 2 notifiable for the first year and after that i would need one notifiable and one non. I kept my cool, checked paperwork which had no reference. I cooled off over the weekend and called back and the chap on the phone told me one notifiable and one non, i relayed what i was told 3 days earlier and then he could not tell me and said he would ring back, and no one did. I wrote them an email and explained the situation. I was called back and a nice lady that told me they would accept my 1 notifiable and 1 non notifiable job and booked my visit in.
My visit was fine and if you know what your doing there should not be a problem. Companies i use are NIC AC, i am now in there gang (well DI, i can go for AC on renewal) and think they are excellent. I have not Used any of the others, i know 2 other guys that have not been impressed with Elecsa and ECA, i think they have both gone to Nappit.
As i did everything correctly, regarding notifying building control i would go for 2 consumer unit changes. My building control officer said if i did a new circuit they would want to visit before i did anything to see the cable run, and then pay a spark to visit after and test it, at