But if there is no payment then they have no leg to stand on. If it’s unpaid it is a hobby, plain and simple. It doesn’t matter whether that hobby is music, golf, photography or whatever, unless they specifically ask a question to which you have purposefully withheld information, or been ignorant in your declaration to the point it would not be considered reasonable in law, then it’s their problem not yours. It’s only an undeclared fact if they ask for it and you fail to declare, it’s not undeclared if it wasn’t asked for in the first place. Whilst I agree the insurers will avoid paying out if they can this can only be done within the framework of the law, they cannot illegally and if they do there are systems of recourse and heavy penalties for them if found at fault.