Postage Stamps how can one tell if they have been used

[in a mo]

We received a letter ,the stamp does not have any INK markings to say it has been used ,the only marking on the stamp are either side a mark that looks like a mark left by a paper clips.any ideas please.

[EvianBaby]

Stamps have little perferated bits in them now so if you tried to take it of the envelope it would ruin the stamp and it couldn't be used again.

[sunny-dave]

Stamps bought from a Post Office are safe to use ...

[EvianBaby]

I know some people who draw a line across the stamp when the attach it to an envelope so it can't be used again. I find it quite sad really.

[Ann]

I had some stamps which were not franked on Christmas cards and I managed to very carefully get them off and use again - but mainly on tax returns or bills ha ha! I am sure they wouldn't know they were second hand if you are extremely careful and patient lifting them off - besides its all good in the name of recycling ;)

[gingejbee]

Those little marks have been designed into the making of the stamp to make removing/ reusing more difficult. Of course, reusing a postage stamp is fraud (!) because you are knowingly not paying for the service. So beware.