I have done a search and can't find any mention from any one about this BUT on the website I noted this rather ambiguous bit of info
Personally I am just not sure whether or not we ALL need to take a test to tow over 750kg or we are OK on our existing licence
If you already have a licence to drive cars or small vehicles (category B and BE), you'll keep your entitlement to tow trailers. Your entitlement to tow trailers will stay as it was when you passed your driving test.
To tow heavier trailers after 19 January 2013, you'll need to follow the rules for new drivers
There is no change to category B entitlement to tow trailers.
If your trailer weighs over 750 kg and the combined trailer and towing vehicle weight is more than 3,500 kg, you’ll need to pass a further test. The trailer you tow must not be heavier than 3,500 kg. This test will be shown on your driving licence as category BE.
So Guys and Gals
Over to you to help me sort it out