Money Saving Expert Martin Lewis has warned drivers to check their car insurance renewal, before new rules come in.
The Financial Conduct Authority (FCA) has banned insurers from increasing prices when existing customers are renewing their insurance.
The FCA has said that by January insurers will not be allowed to charge existing customers more, which is intended to save motorists a lot of cash.
But Martin Lewis issued a warning in his Money Saving Expert weekly newsletter and said the new regulation could actually lead to higher prices in the coming months,
He said : "While the new regime starts in January, insurers will likely start to shift algorithms before - there are even signs now.
"This likely means the cheapest prices will disappear rapidly for those who compare and switch.
"So I suggest everyone check as soon as possible to see if you can cut costs by grabbing cheaper switchers' deals."
Even if your policy isn't up for renewal, it could be worth switching now to lock in cheaper prices, as long as the savings are big, Martin added.
Most insurers let you switch for a £50 cancellation fee and will give you a pro-rata refund, if you haven't claimed on the policy.
Analysis by Martin's MoneySavingExpert site has found that 23 days ahead of renewal is the best time to get a new car insurance quote, and it could halve costs.
