Drivers in the UK pay a combined fee of £333 million order to modify their car insurance policies, it has been reported.
According to figures from uSwitch.com, it costs £22 on average for duplicate documents, cancellations and policy changes.
This amount and more is paid by 14 million customers each year, the consumer website found.
Consistency is needed across the industry if motorists are to save in the future, according to company insurance expert Ashton Berkhauer.
"This would make it clearer for consumers and bring transparency to the market. Currently, making an adjustment to your policy can cost you from £0 to £25 and the price for cancelling a policy mid-term can be unlimited," he said.
Meanwhile, research from Confused.com has shown that there can be a difference of 182 per cent in the cost of car insurance for a normal vehicle and one which has been modified.