If you don’t declare an unspent conviction and need to make a claim, you could find your insurance policy voided if your insurer discovers your conviction. It's important to be honest with your insurer about all elements of your personal history, including some things you might prefer not to share.  You don't have to disclose a criminal conviction that occurs during an existing policy unless it's explicitly stated in your policy that you must.    Though when your policy comes up for renewal you must disclose it, whether you remain with your current provider or switch insurers.  It’s important that you read the details of any policy you’re considering to find out the exact T&Cs before you commit.