If doesn't work like that - if you cancel early then you are forfeiting however much of that year's worth of no-claims you have accrued.
If it did work like that, then people would be chopping and changing to get better deals from month to month without any penalty.
The only proof of no claims accepted in my experience has been either a renewal notice or cancellation letter (and the cancellation letter normally says how many complete years no claims you had when you cancelled).
Oh bother... This affects me then... I've been a very silly sausage...

I left an old insurer after exactly 2 years and sent my proof of NCD to my new insurer and started building my third year, I then cancelled after 9 months because they couldn't cover me on a car and have been with my current insurer for 3 months... So basically I scrapped 9 months of NCD...
My friend had me believe that I could send the proof of 2 years, the cancelation confirmation of the 9 month policy, and the policy confirmation of the 3 month policy to a new insurer, to start with 3 years...
