While it's easy to forget when our car and home insurance needs renewing, paying up after we receive our reminder could be costing millions of people hundreds of pounds every year.

Martin Lewis, founder of MoneySavingExpert, has revealed there is actually a “golden window” that could nearly halve what we pay on car and home insurance. Although it sounds ridiculous, Martin upholds that this is one of the most important tips he has shared and is backed by millions of quotes. In a TikTok clip shared from his Martin Lewis Money Show Live on ITV, he revealed the best time to pay up.

The sweet spot for car insurance is around 26 days before the new policy start date. Getting a quote at that point rather than on or near the renewal date can, for many people, nearly halve the price. "The price you're quoted then can — and it doesn't work for everyone, but it works for many people — beats nearly half what would happen if you got a quote the day of your renewal. Bonkers, isn't it?" Martin said.

The reason comes down to how insurers assess risk. All insurance pricing is based on actuarial models that assess the likelihood of a claim. "The type of people who leave it to the last minute are deemed to be a higher risk than the people who go and get their insurance earlier, so they pay more," Martin explained. His advice was direct. "Even if you're the type of person who leaves it to the last minute, in this one, get your diary, try and pervert the system, do it earlier and you can save money."

For home insurance the same principle applies but the optimal window shifts slightly earlier, with 15 to 20 days before renewal being the sweet spot according to Martin's data.

A viewer named Selene had paid £913 for her car insurance the previous year, assuming the high cost was simply down to her age at 63. After using the 26 day rule, she got the same policy for £468 — a saving of £445, a 49% reduction. A second viewer named Nicolo had been quoted £555 for car insurance, checked again 25 days before renewal and got it for £222. "That's why the sweet spot is sweet," Martin said.

The action is straightforward. Note the renewal date of any car or home insurance policy and set a reminder to start comparing quotes around 26 days before renewal for car insurance and 15 to 20 days for home insurance. Using a comparison site at that point rather than simply accepting the renewal quote from an existing provider is the most effective way to make the timing work in your favour.

A spokesperson for insurance experts UK Sure added: "This is one of those tips that genuinely surprises people when they first hear it, but the logic behind it is sound. Insurers price based on behaviour and shopping around at the right time rather than at the last minute can make a real difference to the quote received. It takes a couple of minutes to set a reminder but the potential saving, as Martin's examples show, can run into hundreds of pounds. Anyone with a renewal coming up in the next few weeks should check when their policy starts and get their quotes in at the right time."

With insurance costs still elevated for many households, getting the timing right on a renewal is one of the simplest and most effective ways to cut a regular expense without changing anything about the cover itself.