How international mail works :postcard:

I base it on my experience as head of a mailroom, I visited Royal Mail in London, Danish Post in Copenhagen, Swiss Post in Zürich to see their international operation, because we could sent our mail via those operators. It might not vary from day to day, but what I understood from talking to representatives they constantly tried to find the cheapest way to transport the mail to the destination country. For instance if we had a large mailshot you could get a better rate, certainly if the mail was non-priority. They could wait to get a better rate from airlines.

Interesting, it could be that the UK is used as transit country for a lot of the European countries, but if they have enough volume for Germany, they can route it directly to Germany.

In Europe trucks are also used to transport mail.

The quality of mail delivery between certain countries is checked by means of letters with chips in them. The chips are read in sorting centres. The people sorting the mail don’t know which letter contains the chip.

The airlines (and truck companies) are commercial businesses and they charge a rate depending on market forces. If a postal company wants the mail on the next aeroplane, it might be very expensive if the plane is full up and the rate can be low if the plane is empty. Postal companies are constantly looking for the cheapest rate for the transport. The contracts between postal companies and airlines are not necessarily examples of privatization or contracting out.

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There are certain countries / area which are becoming more obvious that they’re hubs for mailing letters. It is to some extent corresponding to the major world airports (since some significant % of mails are carried in the belly of airliners)

For example in Europe a lot of it comes through Germany (maybe lesser extent France / Roissy), for South East Asia through Singapore.

I also remember that a lot of mail for Francophone Africa (e.g. West Africa) do get sorted at Paris Charles de Gaulle / Roissy and rarely, but they do randomly get ‘marks’ that they’ve been through there (i.e. mails that get the stamp / sticker or resealed ‘customs inspected’ but from France or other transit country)

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Hello everyone,

I was wondering if there is any article/video/etc. that explains how the postal services handle international letters/postcards; all I seem to find is about packages.
I wanted to know:

  • how one postal service communicate with another country’s postal service;
  • how are the flights chosen;

Try this one:

Who knows how international mail works…?

Newbie here - not sure if this is the right place for my question or not. In addition to being new to PC, I hadn’t sent any international mail from here in the USA in my adult life. While looking for some other info, I came across the USPS notice that international mail requires the “AIR MAIL/PAR AVION” displayed. I have already sent a small number of postcards without this printed on them. So, two questions: 1 - Is it truly required, and if so, 2 - What happens to mail without it? I hope what I have already sent will find its way!

Hey! I had the exact same question when I started. Turns out, you don’t need it, its fine. But I did start a thread in the North American section about this so I’ll see if I can direct you there

Here you go! USA Air Mail?

I didn’t know if the par avion / airmail sticker labels were actually important and maybe required :joy: . Thought people put that on purely for decoration. At least here, it doesn’t make any difference lol. Whether I put it on or not, it doesn’t matter. And if I put it on, but there’s no airmail service, they’ll still be sent by :ferry:

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Thanks so much! Big phew!

I panicked at first too! Haha. Thankfully everyone here reassured me haha

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Here is a link to one of my favorite episodes from one of my favorite podcasts from the fine folks at NPR. It talks about how international postage pricing works. Interestingly, for most of history it worked in the favor of the U.S. but now it’s mostly disadvantaged against us. Fascinating topic and well produced. I hope folks can give it a listen. NPR Cookie Consent and Choices


Hey everyone

I saw a comment yesterday it was in relation to how post cards are delivered from other countries.

My understanding in how postal services do this for example let’s say you have 1,000 letters from Ireland that need to go to America. Anpost would pay for cargo space on dedicated cargo planes going to the country or pay airline that does passenger jets because sometimes they keep a small space for small cargo.

Is this correct or is it done differently?

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Who knows how international mail works…?

You might find this helpful.


Almost ALL my international mail sends out through Los Angeles.

That is basically it, a postal authority chooses a postal route, based on cost and class of mail. They can also send the mail to Royal Mail in Londen and they can forward it together with the UK mail to the country of destination.

It used to be that the post had priority over ordinary freight, but that might have been abolished.

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@michiel071 I would be shocked if Mail still had priority to be honest. You would think with the massive automation in postal sorting now and the amount of planes flying between destinations. That the cost of posting would have gone down instead of increasing. I saw a documentary there a few weeks ago in relation to the US postal service it was a tour of one of these centres were they try to decipher people’s terrible handwriting, misspelling of addresses they said in the documentary at one point there had been 30 of these centres in the country and now they are the last ones left. The guy said in the documentary that the AI algorithm they used has gotten to the point that it can recognise 95% of misspelt and poorly written addresses.

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when i worked over christmas a couple of times in the royal mail sorting centres, it was mostly packages but sometimes letters too, deciphering badly/half-written or incorrect addresses was the bit I enjoyed the most. We were told to just chuck them in a particular bag, where they’d go to place in Belfast where they were supposed to send them to the right place, but I had heard that they didn’t always do a thorough job because there were so many. So if I could decipher the address or add the missing pieces or what have you, I’d take some time out from chucking boxes left right and centre to do so


So interesting! I had never thought about it before. After watching this, I wonder why I it never came across my head to how my letter went from one country to the next! Thanks for posting this video!

In the 1990s I visited Mount Pleasant sorting centre of the Royal Mail and we came by the desk where they tried to correct the addresses. The man told us that postal authorities all over the world sent their international mail with insufficient addresses which they could not correct themselves to London.

The international postal system is a remarkable feat of logistics and coordination, enabling individuals and businesses around the world to send and receive letters and packages with relative ease. But how exactly does it work, and what are terminal dues?

At its core, the international postal system is built on a network of postal administrations from around the world, each responsible for processing and delivering mail within its own borders. These postal administrations, in turn, cooperate with one another through a variety of international agreements and organizations to facilitate the exchange of mail between countries.

One of the key mechanisms that makes this possible is the system of terminal dues. Terminal dues are fees paid by one country’s postal administration to another for the delivery of international mail. These fees are typically set by the Universal Postal Union (UPU), a specialized agency of the United Nations that coordinates postal policies and services among its member countries.

Under the system of terminal dues, each country is assigned a “terminal charge” based on the costs of delivering mail within that country. This charge is then applied to incoming international mail, with the receiving country’s postal administration responsible for delivering the mail to its final destination.

For example, let’s say a person in the United States wants to send a letter to someone in Germany. The letter is collected by the US Postal Service and sent to a sorting facility, where it is then processed and sent to Germany via an international mail carrier. When the letter arrives in Germany, the German postal administration is responsible for delivering it to the recipient. To compensate the German postal administration for this service, the US Postal Service pays a terminal due to Germany based on the terminal charge for German mail delivery.

This system of terminal dues is designed to ensure that each country’s postal administration is fairly compensated for the costs of delivering international mail. It also helps to balance out the costs and benefits of the international postal system, since some countries may send more mail than they receive, while others receive more than they send.

Of course, the international postal system is not without its challenges. One of the biggest issues facing the system today is the rise of e-commerce and the corresponding increase in package delivery. With more and more people ordering goods online and having them shipped from overseas, the volume of international packages being sent through the postal system has skyrocketed.

This has led to concerns about the cost of terminal dues and the impact on postal administrations in developing countries, which may have less robust delivery infrastructure and higher costs of delivery. To address these concerns, the UPU has been working to reform the system of terminal dues and develop more equitable and sustainable pricing structures.

Despite these challenges, the international postal system remains an essential part of global commerce and communication. Whether you’re sending a postcard to a friend in another country or ordering a package from an online retailer halfway around the world, the system of terminal dues helps to ensure that your mail will be delivered safely and efficiently, no matter where it’s going.

So the next time you send or receive international mail, take a moment to appreciate the incredible network of postal administrations and agreements that make it all possible. And remember, every stamp you buy helps to support this remarkable system of global communication and exchange.