Although fully comprehensive insurance is the most expensive type of car insurance, often costing between fifteen and twenty-five percent more than third party fire and theft insurance, it does protect your car and could therefore save you thousands of pounds on repairs as well as compensate you if your car is 'written off'. A 'write-off' refers to a vehicle which has been damaged in such a way that the necessary repairs would be more expensive or equal to the cost of buying a replacement car, that is, it is not worth repairing the car: you are better off buying a replacement instead.