Anyone seeking insurance must disclose all the material facts about the risk involved that he or she knows, or that they ought to know. In other words, the insured should not hide anything. The trouble is certain facts, which the underwriter may deem 'material' may not always be known to the insured. The best principle to follow is: 'If in doubt, mention it anyway.' If you are not sure whether some other piece of information may or may not be relevant, tell your insurers anyway.