Travel insurance policy comes with an expiry date since it is valid for a certain period of time. The policy will not cover each and every trip for the rest of life. The validity period of travel insurance policy depends on the type of insurance you purchased. A single trip policy is only valid for one trip during specific travel period provided to the Insurer before purchasing the policy. While a multi-trip insurance will cover a number of trips until an expiration date as stated on your policy documents.
Different travel insurance providers in Pakistan have different types of policies so there is no hard and fast rule about validity period since it depends on the type of policy you are purchasing. The exact period can be obtained from the travel insurance company but they follow the same criteria mentioned above in this guide.