Yes, if you apply online you'll get a grant email with a pdf of the BVA. You can show the employer the grant notice but likely they'll just use the grant number to check that is your current visa in VEVO. Keep in mind the BVA doesn't go into effect until your current visa ends.
My partner first got her holiday visa in August of last year. She has used it for two holidays so far. Each time allowing her 3 months if she chose to stay for that long.
Does that mean she can't work until august this year or can she work when her 3 month stint is up?