I have two lots of full no claims on 2 separate policy's. Also have full no claims on my bike insurance policy. If I quit one of them policy's after two years I'd loose the ncb. Even though I'd still have 2 other lots of full ncb I'd be classed as not able to use the lost ncb anymore as id be a risk lol total ripe off ncb. If you have a few cars your ncb should count on all