Hello Jay..welcome to the forumGuiness DrinkGuiness Drink
Quick and short answer..
There is NO specific list of quals to be competent to do I&T.
e.g.
Guidance note 3 page 14, par 1.2 (required competence)
and 7671 chapter 61, page 156 onwards... regs; 610.5, 621.5, 631.4
these all only refer to a person being "competent".
as a general rule C&G 2391, would be a good starting point.
Longer bit...
However some local authorities, housing associations, landlords, mortgage landers etc.. may specify that an electrical contractor is a member of one of the approved contractor schemes.
In which case the scheme provider will have their entry level requirements.
The fundamental point is that the guidance and information given in regs, on-site guide & guidance note 3 should be followed and information recorded as per the model forms illustrated in appendix 6 of Regs 7671.
TBH it is no wonder you are confused.....
it IS confusing without an agreed legally enforceable national standard?
it would help if electrics were a bit more enforced say in as manner similar to car MOT's?
but there you go!