MARTIN Lewis has issued a big warning for millions of Tesco Clubcard customers.
The supermarket chain is reducing the value of reward vouchers which can be used to get discounts at restaurants and theme parks.
At the moment, customers can exchange and triple the value of these vouchers at various places including and Zizzi.
But from June 14, Clubcard vouchers will only be worth double their value.
And during the final episode of the series for The Martin Lewis Money Show Live, Martin warned customers to act now to get more points.
The MoneySavingExpert.com (MSE) founder said: "Tesco is reducing its famous Clubcard reward perk from three times to two times value.
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"Currently, 500 points is worth £15 for restaurants like Pizza Express or railcard, or Disney Plus which is the popular one at the moment."
"But this is the important thing - if you swap now until June 14, normally the reward vouchers only last six months - they'll last 12 months.
"Make sure you know that June 14 and get in before then and swap at your highest redemption rate if you can."
Customers wishing to avoid the points devaluation for as long as possible can do so by ordering partner codes before June 14.
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These codes will still be worth the current rate and shoppers will have 12 months from their issue to redeem them.
Tesco has justified the changes to ensure that they can still give Clubcard members great deals.
From Tuesday, April 18, shoppers also will no longer be able to use the Clubcard app.
Customers will need to download a new app - the Tesco Grocery & Clubcard app - in order to keep earning points.
But if you don't download the new app by the time the current apps close, you won't lose any points or coupons.
Tesco told The Sun the new Grocery & Clubcard app is the "easiest way to make the most" of Clubcard offers.
"You can use it when shopping online or in-store as a one-stop-shop to save money, collect points and use your vouchers and coupons.
"You can also unlock extra value from your vouchers by using them with one of our Reward Partners through the Grocery & Clubcard app."
Elsewhere on the show, Martin warned viewers about checking if they're owed tax ahead before April 5.
He discussed how people who work in uniform, as well as married couples, can get money back from the tax man.
Martin explained that those who wash or repair their own work uniform are entitled to an allowance to cover the cost, even if it's just a branded T-shirt.
The minimum allowance is £60 a year, which he explained would mean a £12 a year gain on the basic rate of tax, or £24 on the higher rate.
He warned that there was no need to pay anyone to claim this rebate for you as it's easy to do yourself.
How does the Tesco Clubcard scheme work?
was launched in 1995 and, like Sainsbury’s, shoppers can earn points as they shop which can then be used to turn into vouchers for money off food or other partner schemes.
Each time you spend £1 in store and online, you get one point when you scan your card or app.
You also get one point for every £2 spent on fuel.
One point equals 1p, so 150 points gets you £1.50, for example.
You'll need a minimum of 150 points to request a voucher.
Once you have enough points, you can turn them into vouchers worth the face value to spend in store at Tesco, or you can triple their worth to spend at reward partners, including restaurants, and on days out.
Clubcard holders also get cheaper prices on some items compared to those without the loyalty card.
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For instance shoppers could get PG Tips for £2.50 as part of the Clubcard Prices perk, while those without paid £3.
If you prefer to shop elsewhere, or just want to mix things up, we've tallied up the best supermarket reward schemes.