No Claim Bonus (NCB) is one of the biggest discounts available in car insurance, reducing premiums by up to 50% for claim-free drivers. Yet many policyholders lose this benefit simply because they don’t fully understand how it works. This guide explains the NCB ladder, why even a small claim can reset your discount, how the NCB Protector add-on helps preserve it, and how drivers can transfer their bonus when switching insurers or buying a new vehicle.