Motorists' insurance premiums can rise by almost a quarter if they have a single, three-point penalty for speeding, according to RoadPilot.
The company found in its study that a three-point conviction can result in male motorists paying an extra £85, or 14%, for theircar insurance premiums, on average.
However, there could be a 24% (£158) rise in costs in individual cases.
Motorists could shell out up to £692 over the four years that the speeding conviction stays on their licence as they have to declare it to insurers during the period.
RoadPilot, which analysed 10 leading insurers, also found that there can be a 13% (£69) annual increase in premiums for women who have incurred a three-point penalty. This can result in a rise of more than £276 over the four years.
James Flynn OBE, CEO of RoadPilot, said: "Drivers also need to remember that endorsement points stay on their licence for a long time, hitting their pockets year after year through higher insurance premiums."
Copyright © Press Association 2011