You know, when US Mint or whoever is promising a $1 coin with the American moon landing on it and claims it’s “legal tender” but if you look on the back it says BANK OF SEYCHELLES or BANK OF FIJI so you can’t actually redeem it in the US. But what happens if you go to Seychelles or Fiji and try to use it a a bank or other official government building? Has anyone ever attempted this?
And just to catch the inevitable derail I meant Franklin Mint not US Mint.
Don’t they usually charge a lot more than face value for those coins? If so, why would anyone want to use it as actual money?
Are you sure the US Mint is (or has been) minting coins for other countries? ISTM you’re confusing the mint with outfits like Franklin Mint.
I did it once for a lark. I went to a coin shop and bought a bunch of oversized commemorative coins, mostly from the 1988 Olympics. The coins had face values of $5 to $20 but cost me around 15% more. I went to a restaurant with some friends and we ordered and ate some big meals. Thus having incurred a debt, we presented the coins as payment. The waiter had a long conversation with the manager, but in the end decided to accept the payment without protest.
Note that, unlike what the OP is asking about, all the commemorative coins I used were issued by the same mint that provides our regular coins. I didn’t need to take them across a border to spend them. (Incidentally, does the US mint really sell coins produced by the Seychelles or Fiji? If so, what’s the point? Can’t the US mint produce its own commemorative coins, denominated in US dollars?)
Oh for god’s sake straight dope read the second post in the topic.
Sorry, don’t know how I missed that. 
The US Mint does make commemorative coins and they are denominated in US dollars. But they are sold for more than face value, but you could arguably use them to buy stuff.
I suspect that if the manager was called, it might have been to ascertain whether you’d stolen these coins or not. A friend of mine once told me that when she worked in a convenience store, she occasionally had customers pay with collectible coins. She usually replaced them in the cash register with the equivalent in circulation money and took them home.
I suspect that collectible coins denominated in a foreign currency could be used in the country where they’ve ostensibly been issued, unless they are forgeries (or possibly more likely, reproductions).
Germany has a tradition of issuing commemorative silver coins (used to be ten marks, now ten euros; both are denominations not used for normal, i.e. non-commemorative, coins). They have legal tender status and are sold at face value, even though the intended target demographic are collectors. A friend of mine used to do the occasional prank when he’d use one of them to pay in a store or fast-food venue. Usually he’d get weird looks, but it most cases they would ultimately be accepted after a little talking.
By the way, these coins used to be made of sterling-grade (.925 fine) silver, which, in times of rising silver prices, gave rise to speculators who were hoping that the metallic value of the coins would rise above the face value that they got them for. The mint has since changed the composition to a nickel silver alloy (which got its name for looking like silver but doesn’t contain any).
Sites like Fark sometimes have link to stories about some idjit who stole a relative’s coin collection and took it to a Coinstar machine or whatever to get money for drugs.
There are also the usual tales of someone inheriting a coin collection and just spending the coins.
Since cashing in a Marshall Island’s dollar coin or some as a payment such takes effort, I don’t think there’s a lot of these bozos who have pulled that off.
Someday I’m gonna go to the Maldives, Madagascar or Andorra just to use up the stamps they issued showing American or European celebrities, politicians and sports figures.
As I understand it, a lot of these stamps are fakes, produced by companies with no connection to the countries. I’ve got a rather nice “Abkhazian” stamp set showing Groucho Marx and John Lennon (get it?), but have since learned that the Republic of Abkhazia had nothing to do with its production and that the stamps are not valid postage in Abkhazia.
Maybe they are genuine but still useless - Abkhazia is an unrecognised country, a breakaway region of Georgia. So it could be that the government of that country actually did authorise the issuance of the stamps but does not have postal services where they could be redeemed.
I have often used Canadian commemorative coins in Canada; I got them for a bit below the exchange rate from a couple local coin dealers to use as a lark. Usually when someone found out I was spending them I had offers to exchange them from anyone handy. But those Canadians ------ even Loonies and Two-ies get their attention these days let alone the odd Voyager or Edmonton or such.
And back in the day US commem 50 cent pieces circulated quite a bit; especially the earlier and late ones. It isn’t unusual to find Columbian half dollars circulated all the way down to VG condition or less.
The Royal Canadian Mint has the annoying habit of producing regular coins, and commemoratives, which they put into general circulation. “Look for them in your pocket change!” So you end up with a pocket full of different-looking change, which is only discernible by its size and shape.
You may think you’re using Canadian commemorative coins in Canada on a lark; but to us Canadians, with so many commemoratives issued into general circulation each year, they’re just pocket change.
As I understand it, the breakaway government does issue its own stamps for use locally. For sending things abroad, they sell Russian stamps and hand over the mail to the Russian post.
The US Mint has been doing that for the past 20 years, too. We had commemoratives of the 200th anniversary of the Lewis and Clark expedition on the nickel in 2004-5 and Abraham Lincoln’s 200th birthday on the penny in 2009. And all those state quarters (two different sets starting in 1999) are considered commemoratives. Also the presidential and Native American dollar coins.
But those weren’t the first. The bicentennial coins (quarters, halves, dollars) issued in 1976 were also commemoratives. Canada beat us on that, though. They issued centennial commemoratives in 1967.
The OP is talking about a PRIVATE company like Franklin Mint, NOT the U.S. Mint, and NOT stamps.
The Franklin Mint.
It could be because of age (most of what I use is pre-2000 but --------- just the opposite. They seem to be so rarely seen that EVERYONE wants them. And you don’t want to know the fuss a Tombac or Victory causes. One of these days, I have some odd old large cents with no real collectors value, and I’ll be headed to Canada’s Wonderland ------ I may just have to do it. 
But that is where it gets confusing because the Franklin Mint in particular IS INDEED a “mint” making circulating and commemorative issues for various countries. And in some cases they work a deal with said government to market collectors sets in exchange for a “cut rate” on the regular mintage changes for the various minors. Which is sort of what the US Mint is doing with the proof sets and bullion issues helping offset the costs of our minors. So ------- as an actual numismatist (former professional at that) the differences are not as great as you would think.