How long can I use old stamps for and how do I swap them?

Can I swap my old-style stamps despite only new barcode ones being valid from 31 July?

Royal Mail urges people to get rid of old stamps before huge barcode change - Daily Record

Are stamps with the face of the Queen still valid?

Do Postage Stamps Expire in 2023? - Postagestampsdeals

Stamp swap? I have a large number MNH year sets from The Netherlands (±1960-2000), Suriname (1959-1975), and Dutch West Indies (1958-1976). Interested in MNH year sets of equal cat value. I am

postage stamps by petite-berry on DeviantArt

Books of barcoded Royal Mail 1st and 2nd class postage stamps depicting the head of Queen Elizabeth II on 29th July 2023 in St Dogmaels, Wales, United Kingdom. Non barcoded stamps will

Royal Mail Swap Out Scheme

1735//43 - 1978 A Rate Change Stamps, set of 3 - Mystic Stamp Company