If you passed your driving test after the 1st January 1997 you will need to pass a trailer towing test to get the E category on your licence.
This allows you to tow caravans or trailers over 750kg, or a maximum loaded weight of under 3500kg combined loaded weight for the car and trailer. The loaded Weight for the car can be found on the vehicles log book and the loaded weight for the trailer or caravan will be plated on the ‘A’ frame of the trailer itself. Without your towing licence you would be restricted to a smaller trailer of up to 750kg. This means that anyone under the age of 36 in 2015 would most likely have to pass this test to gain category E.
Most people and companies are still unaware of this and are therefore towing illegally, which means they may not be covered by insurance and in the event of an accident would be liable for any damages.