Any work I do must be tested and certified by a member of one of the recognised schemes or I pay £500+ to notify the work and they send an 'electrician' around to test and certify my work.
Funny that, I just spoke to my LABC, they charge £180 for the notification, but only inspect, no testing. As part of the notification the testing is expected to be done by the DIYer, they MAY only do a limited set of testing. He pretty much spent 30 minutes telling me I should get an electrician to do the work.
I'm planning on doing a full rewire myself, I am not an electrician. However, I can read and understand the regulations, despite the fact they are over complicated, and as far as I am concerned, not clearly defined enough. There is too much room for interpretation for my liking, holes in legislation lead to accidents, bad practice, and should anything go to court, enough for the lawyers to grab hold of to potentially get someone guilty off the hook.