Failing to promptly provide a reasonable explanation for the denial of a claim, when done with enough frequency to indicate a business practice, is an unfair claim settlement practice and therefore an unfair insurance practice. It is not merely contractual liability, because the question describes a regulatory claims-handling violation. It is unrelated to a grace period, which concerns time to pay premiums. It is also not necessarily a fraudulent insurance act because fraud requires deception or false representation. Pennsylvania’s Unfair Insurance Practices Act specifically identifies as an unfair claim settlement practice the failure to promptly provide a reasonable explanation of the policy basis, facts, or law for denying a claim or offering a compromise settlement.