Your no claims are still protected if you switch at renewal. The new company will regard it as having not made a claim. You will be advised that you can make three claims in any two year underwritten period, but that would/should be with the same underwriter. Once a contract has lapsed, another insurer cannot penalise you for a claim made under a contract it is not covering. Though you may find that if you make a claim with a new insurer, your NCB will still be protected till the end of the contract, but if you have made three claims you may not be offered the possibility of protecting your NCB at renewal. Protected NCB is technically another insurance product, hence why you pay an additional premium for it.