The reason companies offer a discount for buying online is that they have not got to pay any commission to insurance brokers or agents. This can be as high as 15% for the larger brokers. The insurance company also needs less staff to deal with insurance this way, thereby saving further money. Also, if you get a high renewal premium it may be an idea to ring the company, they may give you a discount to retain your business. Most larger companies have retention departments. I did this and saved approximately