Non-postmarked stamps

I’m not a complete skin flint, but just had a package arrive with one of these large 1st class ‘package’ (1PK) stamps, that not been postmarked or marked in anyway.
As it’s to the value of £2.24, I’m just wondering if I can re-use it?

Got a old copy of STW I was gunna dump, Issue 25 (the only one I ever bought – was enough to convince me the magazine was not for me), as it no longer available on the back issue page I was gunna offer it out & this stamp seems the perfect way to send it..

Good luck removing it from the parcel. 🙂

my mum, who is a skinflint, does this all the time – hardly ever buys stamps. just stick them back on with pritstick.

Yeah, it’s easy to do and works. Think it’s a bit illegal.

You just stole £2.24 off TEH QUEEN! Think of the children, please.

The post that gets delivered to work usually has no post mark on the stamps.

Sometimes the postie will scribble in pen over the stamps so I guess you must be able to use them, although you ought not to of course but if the PO can’t be bothered to look after their interests why should I?