[GoinAllTheWay]

By law, insurers do require a signed request to cancel a policy that way they have proof that you did request to cancel the policy.

Sounds to me like your broker may have dropped the ball a tad. The only reason why ING would need proof that you started a policy elsewhere is if you are trying to back date a cancellation and they want proof that you didn't need their policy past that time. This is the only reason I can think of.

You have every right to cancel your policy for what ever reason at what ever time, if you requested cancellation of an auto policy a couple weeks ahead of time, say for an upcoming renewal, they would not ask you for proof of insurance elsewhere.

Honestly, don't let this reflect on ING poorly, I'm willing to bet your broker was late sending in the cancellation request and was the cause of the problem, not the insurer.