I had a question. What happens if we don’t put enough stamps on a postcard? do the postcard arrive anyway with a special note?
because i think I made a mistake on a postcard to a member,I put a forever regular stamp instead of a international one.
if your postcard was sent domestic (in the usa), the receiver will have to pay the difference if the post office catches the mistake. in sent internationally, if you did not include your return address, it will be sent on and and the receiver in that country would have to pay the difference of postage due or the full amount it would cost to send a postcard from that country. that what happen to me in the past, maybe it has changed.
At the worst, the other person may have to pony up for the insufficient postage. In one case, I forgot to put any stamps on an envelope to Canada. Unbelievably our top notch USPS processed it anyway and was delivered to the member.
One more thing: I often put a ton of low-value stamps on, so many that I need to get my calculator out to make sure it all adds up. I can’t imagine in a million years a postal worker breaking out a calculator to see if there is a $0.05 or $0.10 disparity, especially someone abroad, if the numbers look roughly correct. They’re too busy.
wait until it arrives - the usps will process it. but the sorting machine might nit catch that the postage is wrong. and as @Walden said, they are to busy (many times) to correct the mistake. also, in other countries, they used a different system in postage due - remember in the uk, it was a big T with a line where the amount was due. when it arrived here, the post office didnt know what that meant. so they might not understand if it was caught what postage due meant there,
If the USPS don’t spot the underpayment, then it’s highly unlikely the recipient will have to pay anything. For example, if I send a postcard from the UK to the USA with insufficient postage, no USPS employee is going to know what the correct UK postage rates are, nor would they care - the USPS never sees any of the money represented by that postage directly.
Instead, it’s up to the sending postal authority to confirm that sufficient postage has been paid before they put that piece of mail into the international postage system.
That’s only the worst case. Most often nothing happens with international mail. It just gets delivered. For postage due in another country, the post of the sending country needs to mark it with the postage due (incoming mail from abroad is not checked!). Then the post operator at the destination country needs to charge it. It doesn’t happen too often!
I receive a surprising number of cards from the US with just a Forever or a Postcard stamp on, so severely underpaid - I have never had to pay anything. Obviously I can’t tell how many other cards with insufficient postage were caught by the USPS and never made it out of the country, but if the card arrives at its destination (which I think is highly likely), I don’t think you need to worry the recipient will have to pay postage due.
Before I really started travelling I went to my post office and asked for stamps so I could send from any country to Germany, but the worker must have understand that I wanted to send from Germany to any country. So I tought, that I had to use german stamps, to send to Germany. I send around 35 cards from around 12 european countries with the wrong stamps (In every country the stamp value was not enough, some times, in Great Britain or Hungary not even the same currency), and they all arrived!
On card from Italia had an italian stamp covered mine, I dont now who put it there, but that was especially nice!