Not sure???
I've gotten the odd Canadian mailing where the stamps look un-touched and wondered myself if they were still usable.....I also wondered if they are using an "undetectable" cancellation system?
The question is, is Canada post neglectful and one mailing wasn't processed, or are they high-tech-sneaky and marking the stamps in an mysteriously invisible ink????
...........only the posties know..............

However, on that note, it wouldn't make any sense to use invisible ink: Your average Joe has unused stamps. It wouldn't be a good idea for the gov't to start sending back every letter to every average Joe for more postage when, in Joe's eyes, he used a good stamp! You wanna see a country go postal on the postal service, there's a way LOL!

Not sure if you can do anything with it in 'the states' but I reuse stamps which have not been canceled all the time here in Canada.

Since I started trading three years ago, I find that a lot of bubble envelopes are getting to me with lovely stamps which haven't been marked. Trading seeds has become quite cheap with Canada Post's help!!

If you ever do an SASE with a Canadian, you could certainly use it!

Can I do anything with it?

Take up stamp collecting?

As trading becomes more popular, is the PO going to raise rates even faster to cover the loss from those of us reusing uncancelled stamps?

I think it has to do with thick envies that would clog the machinery. In the States, it costs 13¢ extra for hand-cancelling if the clerk notices it.

My beef is with the new self-stick stamps. I love 'em, but when I stamp a bill only to find I'm going by its destination later in the day, I can no longer steam off the unused stamp.

Keep in mind: your 89¢ Canadian stamp is worth only slightly more than 76¢ US. ;-)