What type of policy allows the insurer to cancel at any time with written notice?

A cancelable policy allows the insurer to terminate the coverage at any time, provided they give written notice to the policyholder. This type of policy grants the insurer the right to cancel the policy for a variety of reasons, which can include non-payment of premiums or the insurer's assessment of risk.

In a cancelable policy, the flexibility for the insurer to end the agreement is a unique feature that significantly differs from other types of policies. For example, conditionally renewable options often stipulate specific conditions under which coverage may be renewed or canceled, but they do not allow for outright cancellation at any time. Optionally renewable policies also secure the right to cancel at the end of a term, but again, they are not as flexible as cancelable policies because they typically allow renewal by the insurer under certain conditions.

Thus, when considering the question presented, the defining characteristic of a cancelable policy is its affordance to the insurer to terminate the policy with written notice at any time without necessarily providing a reason. This context is crucial for understanding the implications of such a policy for both insurers and policyholders.