Did you pass your driving test before January 1997?
If you did, then it is possible that you will not need a B+E licence as long as you are not towing a combined gross weight of more than 7000kg.
If you passed your test after January 1, 1997 then you may need a B+E licence if you are going to tow a combined gross weight of more than 3500kg.
Still not sure? Please find below a step by step guide that will enable you to determine whether you need the licence or not.