I'm not recommending that you lie to your insurers when making a claim. What I am doing is saying that if you do lie but is wasn't a whopper, the insurers may no longer be able to use it to escape paying you out.
The Supreme Court has given its blessing to a change in approach where the insurer has been told a collateral lie - something which is irrelevant because the claim was justified whether that something was true or false. Say you are making a claim after your house burnt down in an accidental fire and you lie to your insurers that you dropped the match in the living room when, in fact, you dropped it in the dining room. Probably irrelevant and collateral.
However, be in no doubt that your insurers can send you packing if your claim is fraudulent or you have exaggerated it. And probably also where one part of the claim is genuine but the other part is fraudulent.
In the case before the Supreme Court on 20 July 2016, the collateral lie to the insurers of a ship whose engine room was flooded was not fatal. The claim by the owners was for over 3,000,000 euros.