Which of the following facts must a policyholder disclose to insurers at renewal?

A policyholder is required to disclose details of any material changes to the risk that have occurred over the last 12 months at the time of policy renewal. This requirement is rooted in the principle of utmost good faith, or "uberrima fides," which obliges the policyholder to provide insurers with all relevant information that could impact the insurer’s decision on the renewal of coverage or the terms of that coverage.

Material changes may include factors such as new risks that have emerged, changes in the insured property, alterations in the business's nature, or any other significant developments that could influence the risk assessment. By disclosing such information, the insurer can make informed choices around underwriting, premium adjustments, and policy conditions.

While facts that lessen the risk or facts of public knowledge may sometimes be relevant, they do not carry the same obligation for disclosure as material changes. Facts of law are generally not required to be disclosed as they do not pertain directly to the risk assessment from an insurance perspective. Therefore, the emphasis is on keeping the insurer fully apprised of any changes that could materially affect the risk profile.