Bosses at Royal Mail are reminding people to "use up or swap out" their non-barcoded stamps.
As part of a modernisation drive, stamps which do not have a barcode are being phased out and will no longer be valid from July 31.
They are being replaced by stamps with a barcode which enables the introduction of added security features and paves the way for innovative services for customers.
Matthew Parkes, managing director of Stamps and Collectibles, said: "We don't want any of our customers to be out of pocket.
"In order to give our customers even more time to use up any remaining non-barcoded stamps, we introduced six-month grace period starting from the original deadline of January 31, 2023, where non-barcoded definitive stamps will still be delivered as normal.
"We continue to encourage customers to check their purses, wallets and drawers to find and use their non-barcoded Definitive stamps before the final deadline of July 31.
"But even if they miss this date, there is currently no time limit on customers swapping their non-barcoded stamps for barcoded stamps via our free Swap Out scheme."
For more information on how to take part in the Swap Out scheme, visit royalmail.com/sending/barcoded-stamps.
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