I always shop around at renewal time. A couple of years ago I got my renewal letter saying they'd checked the market and the lowest price was £X. I got a quote for £Y from someone else, which saved me about 15% of the premium. When I phoned the previous insurer, they said they could match it, but I told them where to go as they should have given me a better offer first time round instead of hoping to make a killing if I had accepted their price.