That apart as I think I have reported on this forum previously I contacted ASET up here in Aberdeen and was told that I didn't need to provide any evidence of being a tradesperson as a pre-requisite to going on a Part 'P' course. I don't doubt I could attend the course and pass the Friday afternoon exam without too much difficulty. Coming from a highly regulated industry i.e. shipping I find this strange.
Does that get you an actual registration with a competent persons scheme? There seem to be a few colleges which run somewhat nebulous "Part P" courses but it's not entirely obvious that the resulting qualification counts for much.
I think there are eight bodies authorised to run schemes for Part P "full competence" registration. I'm not familiar with all of them but I know that NAPIT, at least, do require you to hold a variety of qualifications and pass a practical assessment. According to their website you need to hold an NVQ Level 3 (or equivalent) at the point of registration, and within 12 months you need to obtain both an ISO 17024 certificate of competence and a C&G2382 or equivalent certificate. I don't think it's feasible to get an NVQ Level 3 in a five-day course since there is quite a lot of on-site assessment involved. I guess it's possible that some of the other schemes might have less onerous entry requirements but I'd be a bit surprised if any of them were quite as relaxed as ASET seem to be.
It probably is true that you can go on a 5-day course and end up with a Part P "defined scope" registration. This is a much more restricted thing: it's intended for kitchen fitters, plumbers and other tradesmen (who just need to be able to do things like move a kitchen socket) and doesn't enable you to self-certify a complete installation.