I am afraid it will not be covered by your household insurance policy.
Unfortunately trailers are very easy to steal so best advice is to have the roof postcoded in large letters with your home postcode. If it has any glass windows then have them etched. Keep the serial number of the trailer in a safe place just in case it gets stolen. It is always best to have it parked well out of sight or even better locked within a building.
Nope. My car insurance covers mine 3rd party. Mine will be parked completely out of sight though and will have the postcode on the top in large black paint!
Thanks for replys unfortunately nfu out the question as I don't have anything else insured with them. I will ask the company i have the field insured with to see if they do anything, it would be covered by them if I was to park it in the field but that would just be asking for trouble . I bought a roof post code a few years ago but never put it on due to laziness :/ maybe I will hunt it out and see if it has any sticky left.