The Financial Ombudsman Service (FOS) has released a consumer fact sheet clarifying the importance of medical non-disclosure.
It also clarifies what assistance FOS can provide should a complaint arise from an insurer failing to pay a claim due to non-disclosure.
Earlier this month the government announced it was going to change the law, to clarify what information consumers need to "disclose" to their insurers.
FOS said this would bring the law into line "with the long-standing approach taken by the ombudsman" to deal with complaints.
The Consumer Insurance Bill, when passed, will place the burden on insurers to ask the correct questions to disclose any previous medical conditions.
However, if a client is asked they must answer fully.