12N is the standard socket for trailers, horse boxes etc.
12S Incorporates extra functions for caravans including leisure battery charging and reverse lights
13 Pin euro socket combines all wiring into one socket for more modern caravans and some trailers
Vehicle Insurance and Towbars, It was reported in one of the caravan magazines that some insurance companies were turning down claims if the vehicle concerned had a towbar fitted and the insurance company had not been advised. It would be wise to clarify with your insurer to avoid any problems should you need to make a claim.