It depends upon how far up you want to go. As far as electrical install goes it jumps from approved to tech in one go but you will find city and guilds 236 C course or its modern equivalent and three to four years in a technical(ish) capacity are needed. You could always have a go at ONC, then HNC and then HND in electrical engineering to get your Eng. ticket but it starts getting miles away from installations. Good luck with your training.
You should be ok to apply for your approved tag 2 years after you get your electrician grade. Tech status will come 3 to 4 years later depending upon experience and whether you can get your boss to give you a good ref. on the application form or when you reach 27.As far as install work goes, getting your tech card isn't what its cracked up to be but it may help you move sideways into a more technical job rather than stick at bending conduit for ever.
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