Can You Use Unfranked Stamps?

Royal Mail were alerted to the issue by Radio 4 consumer finance programme Moneybox. Buying and selling unfranked stamps isn't in itself illegal if they are for collections. Reusing unfranked stamps as new is, however, an offence. You can hear the Moneybox radio article here, commencing at 08m 10s.

Can the post office tell if you reuse a stamp?

“Royal Mail can also detect whether stamps have been used before to protect its revenue. In cases where this has been detected, there will be an extra postage charge to the customer. ... These are left on the envelope when the stamp is peeled away, rendering the stamp useless.

Can you use old stamps that are not forever stamps?

You can use them any time. Any combination of stamps may be used in meeting the postage requirements. You may think it looks “tacky” to have a variety of stamps on your envelope, but the Post Office encourages you to utilize all the stamps you have.