OP
Arnold Layne
It's an interesting question Rowden and a rather unusual one for an apprentice, but it is really good to have a plan. There are a number of schemes, NAPIT, NICEIC and ELECSA all of various quality but all offer a part P scheme, which is what I assume you are after. You would need to contact them to find out the individual entry criteria. But bear in mind that there are costs involved in all and that the Part P scheme is currently under review so you may wish to wait until you finish your apprenticeship before registering, as the scheme requirements may have changed by then, and if you don't intend to work as an electrician in the UK for awhile then you may as well save the money.