Me & my brother work with vans and were both legal to tow trailers even though it aint on our license!! It goes by weights mostly. He had a accident and thought he was going to get hung but traffic officer explained it didnt matter as the trailer he had was matched by the weights in van etc so take this how you like but he explained you cant tow a trailer with a escort for example but could tow said trailer with a van. So dont know what is correct or if laws up here in scotland are different? Or maybe traffic officer thick as mince