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| Example of old 6-digit postal code vs. newer 5-digit code |
New postal code numbering format
The code breaks down like this:
- The first 2 digits correspond to the largest administrative units: either the province or the metropolitan city.
- The 3rd digit corresponds with the smaller sized city in the province, or the district-level area within the large city.
- The last 2 digits are a serial number that corresponds to a specific area within the local district.
Here are two examples of the new codes:
03139 corresponds to: Seoul Metropolitan City, Jongro District, Supyo 22nd Road, #17
26412 corresponds to: Gangwon Province, Wonju City, Namsan Road, #203
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| Examples of the new codes and their corresponding street addresses |
The numbering scheme traces a snake-line, flowing from the northwest part of each region, worming its way down to the southeast. Below is a map of the codes comprising the largest regions, the first 2 digits of the number. You can see the ordering illustrated in purple.
The numbering begins in the capital and traces a route through:
Seoul city → Gyeonggi province → Incheon city → Gangwon province → North Chungcheong province → Sejong city → South Chungcheong Province → Daejeon city → North Gyeongsang province → Ulsan city → Busan city → South Gyeongsang province → North Jeolla province → South Jeolla province → Gwangju city → Jeju island
The same snake-line numbering scheme happens at the local level. The Korean Postal Service uses the example of the postal code 03056 to illustrate how this numbering system works at each level.
You might be asking yourself: why change the system yet again?
Seoul city → Gyeonggi province → Incheon city → Gangwon province → North Chungcheong province → Sejong city → South Chungcheong Province → Daejeon city → North Gyeongsang province → Ulsan city → Busan city → South Gyeongsang province → North Jeolla province → South Jeolla province → Gwangju city → Jeju island
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| Nationwide ZIP code prefix map [modified from Song's World] |
Example: Finding postal code 03056
The same snake-line numbering scheme happens at the local level. The Korean Postal Service uses the example of the postal code 03056 to illustrate how this numbering system works at each level.
- The digits 01~09 correspond to Seoul, so the 0XXXX tells us that the location is Seoul, and the 03XXX specifies it in Jongro District in the heart of Seoul (the blue area in the map below).
- Next, adding the third digit 030XX gives us the 9th basic administrative zone in Jongro (the green area on the map below). All numbers between 03000~03299 correspond to Jongro District. That allots 300 numbers specifically to Jongro.
Now here's something fun. Jongro has only 199 actual designated locations, 03000~03198. Those 101 remaining allotments, 03199~03299, remain preliminarily assigned to Jongro. That might seem illogical, since if we follow the rules of this snake-line numbering then it seems to preclude later numbers from having any matching locations. Jongro cannot just magically grow more space at the southeast corner in which to shove those 101 allotted numbers. But it makes sense as a scheme to maintain consistency, like how an apartment that has 10 rooms per floor will number them 101~110 but the next (one floor above) takes #201 rather than #111 even though it is technically the 11th room in the building. - Last, adding the last 2 digits "56" to 03056 narrows down the location down to a city block enclosed by major roads (the orange area on the map below). The Postal Service website notes that this "block" covers an area that contains portions of 가회동 and 계동. A bit more on that below. Finally, the street address itself will need to be utilized from that point onward to ensure the letter arrives at its destination.
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| Narrowing down the location of postal code 03056 |
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| Postal Code 03056 region, an urban block in Seoul near Changdeokgung Palace |
Postal codes: Old vs. New
You might be asking yourself: why change the system yet again?
One of the benefits of this new system is that it more artificially imposes location information. Korea has been dramatically altering its postal address system for a few years now. You may remember that addresses changed format back in 2013, from being based on the old lot-numbering system (whereby buildings were numbered temporally, newer buildings having higher numbers) and transitioning to a more Western-style system based on road names and spots along the road being numbered sequentially in spacial order.
The new postal code system essentially does the same, by depreciating the old postal administration zones and regularizing them into more of a block-based system. To see what I mean, have a look at this image:
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| Korean postal codes: old vs. new [Image: Sejong Special City] |
Here, you can see the old 6-digit codes, and their boundaries, in blue. The newer 5-digit codes and their boundaries are in red. You can see that while the older system was more effective at preserving historical and social spacing, it could be complicated. The newer system artificially regularizes locations, without special regard for -gu or -dong administrative divisions.
Working with the new postal codes
It will be interesting to see if any difficulties arise from the new postal code system. Personally, I don't expect it to make nearly any difference in the lives of ordinary people. I think this quote really sums up how most people will experience this change:
"No one told me about the change," a housewife surnamed Choi complained. "It will not change my life anyway, because I don't use the postal service often. I don't remember my old zip code anyway." [Korea Times: "Few know new ZIP code system"]
That last line is important. I've met very few people here in Korea who knew what their own postal code was. On most domestic online ordering sites, the website automatically will look-up your ZIP code based on the building address you input. I can't count how many times I see distraught postal workers look up the ZIP code themselves when someone comes into the post office with an address but no ZIP code. I doubt many will even be aware that a change took place.
And really, it's not nearly as big a change as moving to a street-based numbering system. I do recall some confusion when that change came into effect. But even today, I still see people and even businesses using the old lot-based system. Government buildings and government organizations are the only groups I've seen reliably and consistently use the street-numbering system. The local portals' map services do indicate street names now on their imagery, and officially use the street-numbering system, but include the old system as well.
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| Address formats: new and old |
Above, a location in the 03056 postal code. Naver Maps officially lists this location as 북촌로 40 (new road number system) but also includes 가회동 207 below that (older lot numbering system).
So overall, even though it was announced several months ago, I predict few people will be aware of the change, but that won't really matter. Life will go on as always. And very likely, your letter or package will be delivered, no matter which address form you use. I just got a 택배 delivery to my apartment today. It included, on the address label, my -dong, my apartment complex's name, and my room number. No lot-number, no street address, no postal code of any kind. And that's actually pretty routine.
But if you're the curious kind, and if you read all this then you probably are, then via a tip on the Marmot's Hole, you can find your own new 5-digit postal code at the Korean Postal Service's English website here:
So it's a fascinating case of major, nationwide, government-mandated change, but like Ms. Choi above, I doubt it will have any real effect on the lives of many people. Now that's the type of government change I can get behind.
[Images from Korea Postal Service unless otherwise indicated]
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