So we just ordered our wedding invitations, which should be ready in about 2-3 weeks, and we’ll obviously be pre-addressing and pre-stamping our reply envelopes for our guests. However, I’ve got relatives & family coming from our neighbor to the north, Canada, and I’m assuming that I’d have to stamp their envelopes with Canadian postage so they can get back to us in Boston… Do the US Post Offices carry Canadian stamps for this type of scenario? Are there good places in the US where I could go for this kind of situation?
Asked at my post office 15 minutes ago and they said no. I can tell you that you can order Canadian stamps online from canadapost.ca … Can also order US stamps from usps.com if the need arises.
Every post office sells “international reply coupons”, which are the equivalent of “gift certificates” for reply postage from other countries. Just buy a few and stick them in your Canadian invitations.
I had to buy some recently because the Ceremony of the Keys at the Tower of London requires a SASE… Of course, the USPS doesn’t sell British stamps, so I had to get the IRCs. It was no problem! 
International Reply Coupons are handy when there are no other options, but I’ve heard that they can be a pain to use on the other end. Plus they get a bit pricey when compared with the actual stamp costs. I think the idea of ordering stamps online from the Canadian Post Office is a great idea. (Although a trip to Toronto, Montreal or anyplace else in Canada would be wonderful to do using stamp purchasing as an excuse.)
You might want to call stamp dealers in your town, too. At least in Canada, some carry U.S. stamps for these purposes – it might be true the other way.
I’ve used IRCs for submitting manuscripts, and while they worked fine, they were pretty expensive.
Hrm, ordering them from the Canadian PO sounds like it’s probably the best option. It’s only a small reply envelope, so hopefully weight won’t be too much of an option. We’ll probably overdo it on the postage a little bit just to be sure. It still looks cheaper than the IRCs. Thanks guys!