The International Standard for Identifying Postal Items

Summary

Have you ever received a parcel from overseas? I did recently, from Switzerland! Looking at the envelope, I realised the format of the tracking number (UT038926726CH) was in a very similar (if not identical) format to ones I'd used frequently here in the UK. I'd been receiving emails from Royal Mail about the parcel, so I just presumed that there was some data-sharing agreement in place with Swiss Post and Royal Mail had just given the parcel their own internal reference number. But seeing the reference number printed on the envelope from the get-go made me want to see what Swiss Post had to say about it... The same tracking number works across multiple carriers, and it's the same format as all the UK ones! What gives?? Enter: the United Nations Universal Postal Union The Universal Postal Union (UPU) is an agency of the UN that coordinates postal policies to facilitate post flowing across the world. As part of this, it publishes the S10 standard for the identification of postal items in a 13-character format - ie. what we've been seeing on our parcels! If you're interested in learning more about the UPU's interesting 150-year history, you might want to check out this article written by fellow webring inhabitant Imaan! Each country's national postal service is assigned as having exclusive reign over S10 codes for that country, and they go about issuing S10 codes from their country. Tracking Number Format As it turns out, the structure of our tracking number has a strict design, and our tracking number contains four distinct things: Character number Format Description 1 and 2 2 letters Service indicator 3 to 10 8 digits Serial number 11 1 digit A check digit 12 and 13 2 letters ISO 3166–1 country code representing the origin of the item The Service Indicator The first two characters represent the service that's been used to post the item. There's a fairly extensive list in the standard, with specific options for tracked post, letter post, parcel post... the list goes ...