You have probably been looking for temporary car insurance to cover yourself to drive a car for a short period of time. However you have found that insurers who provide this type of insurance have minimum age restrictions which means that most providers require you to be at least 25 years of age.
You used to be able to get temp cover under 21 however it became difficult for car insurance companies to be able to provide this service competitively. The reason is that with a normal car insurance policy you pay for an entire years premium. If you add the premiums for all their customers together this makes quite a substantial pot, enough to easily cover the cost of the claims. As the under 25 year old are in a higher risk group they are more likely to make a claim.
With temporary car insurance the customers may only take out cover for as little as a single day. If they make a claim the insurer has much less in the pot to pay out. This means that insurers stopped providing a temp cover under 21 policy. So if you are under 25 you will not be able to get a daily car policy to cover you to drive a car or a van.
Fortunately there is an affordable alternative if you are unable to temp cover. Instead you can get a pay as you go policy, instead of insuring yourself from between 1 and 28 days you can get insured for a month at a time. This is a monthly pay as you go insurance that does not require a deposit and can be cancelled at any time without incurring any fees. You can obtain cover from as young as 17 years old.