Royal Mail has extended the length of time you have to use traditional stamps before they become no longer valid.
Classic stamps are being replaced by ones with barcodes, which allow recipients to watch videos and greeting messages from senders.
The deadline for which you have to use older stamps has now been extended by six months, to July 31, 2023.
You can still use themed, commemorative and non-barcoded Christmas stamps beyond this date.
The previous cut-off point was January 31, 2023.
You can also exchange your old stamps for free through the Royal Mail 'Swap Out' scheme.
To do this, download a 'Swap Out' form on the Royal Mail website, call up Royal Mail on 03457 740740, or pick up a form from a local delivery office or Post Office.
If you’re downloading the form online and you don't have access to a printer, you can instead complete a web form and request for it to be posted to you.
Once you’ve filled it out, post back the stamps you want to swap using the Freepost address. Your new barcode stamps should then arrive in seven days.
You will need to complete a standard form for stamps worth up to £200, or a Bulk Stamp form for stamps worth more than £200.
There is no limit on the number of forms you can request. There is also currently no deadline for swapping old stamps.
Royal Mail told the Mail on Sunday: "In order to give our customers even more time to use up any remaining non-barcoded stamps, we have decided to introduce a six-month grace period starting from the original deadline of January 31, 2023, where non-barcoded stamps will still be delivered as normal.
"To make things even easier for our customers, we have also agreed with the Post Office to include the forms to enable customers to swap stamps alongside freepost envelopes in its branches."
Royal Mail has yet to confirm when its stamps will start to feature King Charles III following the death of Queen Elizabeth II.
New coins featuring King Charles III have been unveiled by the Royal Mint.
The King’s portrait will appear on 50p coins from around December, as currency featuring the new head of the Royal Family gradually enters circulation.
