MARTIN Lewis' MoneySavingExpert (MSE) has issued a warning over old stamps before households decide to bin them.
Royal Mail started replacing all current stamps with new style designs last year.
If you continue to use old stamps, you could face a surcharge in the same way that you would if you sent mail with no or insufficient postage.
The only valid designs are those with barcodes on them, featuring King Charles' image.
Alternatively, you can swap your old ones for barcoded versions for free through the Royal Mail scheme.
The team at MSE recently tweeted: "Got old stamps lying around? Don't bin 'em.
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"MSE's Helen's just found £8.10 worth of non-barcoded stamps in an old purse, and luckily Royal Mail's FREE 'Swap Out' scheme is still open."
Royal Mail said that every barcode will be unique and will enable the introduction of added security features - including information about relevant postal services.
Although, not every stamp will become invalid, some limited edition versions will still be valid.
The Royal Mail said: "These stamps are mostly kept by customers to send their Christmas cards and we anticipate that the vast majority will have been used by the end of this year.
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"We are still adding a barcode to Christmas stamps, but non-barcoded Christmas stamps will remain valid so can continue to be used after July 31, 2023 and therefore there is no requirement to swap them out."
The initial deadline to swap out all of your old stamps was back in January 2023, but Royal Mail opted to extend this to give customers more time.
Below we reveal how you can exchange your old stamps for barcoded versions and how much stamps cost.
What can I do with my old stamps?
Stamps can be traded in before the cut-off deadline – and Royal Mail will let you do it for free.
Customers will have to fill out a "Swap-Out" form on the Royal Mail website or call the postal giant directly to request a form.
Alternatively, you can get one in person from a local delivery office - but not a Post Office.
You can find your local delivery office by using the online locator tool on the Royal Mail website.
Four ways to get the 'Swap-out' form
- Print out the form from
- Call Royal Mail's customer services team on 03457 740740 and ask for the form to be delivered at home
- Visit your local post office to pick a form yourself
- Keep an eye out for a Swap Out form in your letterbox
You'll then have to post back the stamps you want to swap to a Freepost address.
But if you have more than £200 worth of stamps, Royal Mail recommends these are sent by recorded delivery.
And you'll need a Bulk Stamp Swap Out form for stamps worth more than £200.
There's currently no deadline on when you need to complete the swap, but it might be best to do so sooner rather than later in case the scheme closes.
Royal Mail says it will try to make sure all stamps are swapped in seven working days.
How much do stamps cost?
First-class stamps currently cost £1.25, but they'll be rising by 8 per cent on April 2, 2024.
This means punters will pay an extra 10p per stamp whenever they want to send off a first-class letter - and it's not the only increase.
Large first-class stamps will be 15p more expensive and second-class stamp buyers will have to pay an extra 10p per item, a 13 per cent increase.
Money guru Martin has advised Brits to buy them in bulk before the new prices begin to save a decent chunk of change for all their posting needs.
He said: "For years, every time stamps go up in price I've suggested people stock up and bulk-buy in advance, as provided the stamp doesn't have a price on it and instead just says the postage class, it's still valid after the hike.
"This has been an effective tactic, as a first-class letter stamp is now £1.25, soon to be rising to £1.35 – in 2012 it was just 60p. So you may as well stock up now."
According to his (MSE) site, It's the third time first-class stamp prices have jumped in the last year.
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Brits only had to part with 95p just over a year ago, in March, but that quickly jumped up to £1.10 only a month later, in April.
Then, in October of the same year, they shot up again to £1.25.
How are postage prices decided?
Royal Mail typically increases the price of stamps annually.
Normally, it gives customers advance warning of around a month before pushing up prices.
This year the hike was announced in March.
Royal Mail said it is hiking the price of postage due to the decline in the number of people sending letters.
The number of letters being posted has dropped 60% since 2005 and around 20% since the start of the pandemic.
It has also blamed rising inflation for the increase