How an address is written in South Korea

An address in South Korea is written in this order: street name and house number, then district, then town or city, then do or si, then postal code (five digits), with the postal code in capitals. The strongest check here is the postal code itself: GeoNames' postal code list (31 October 2026), with 34,249 postal codes for South Korea, current codes only.

The order the lines go in

The parts are named rather than filled in: Spaw does not know an address in South Korea and will not invent one. This block is produced by the same function that rewrites a real address, so the line order, the capitals South Korea asks for and any text its operator prints on every envelope are the checker's own behaviour rather than a second description of it.

Organisation
Street name 12
Flat or unit
District
Town or city
Do or si
POSTAL CODE

No recipient line: nothing in the response is about a person, so the name the envelope carries is not part of what is checked.

field	called here	required	capitals
organization	Organisation	optional	—
addressLine1	Street name	required	—
addressLine2	Flat or unit	optional	—
dependentLocality	District	optional	—
locality	Town or city	required	—
administrativeArea	Do or si	required	—
postalCode	Postal code	required	yes

In South Korea the house number follows the street name, and that is the side it is written back on when the checker rewrites an address. The postal code is written after the town.

The table also carries a local layout for South Korea, and it runs the other way round: the do_si first and the street last. The order above is the Latin one, which is what an address rewritten here is written into. What local-script rendering means.

Can Spaw tell whether an address in South Korea exists?

No. No address register is installed for South Korea, so exists answers null: not evaluated, never no. An address can be perfectly formed and still not exist, and nothing here will pretend to know which.

A postcode directory answers a different question. The postal code is confirmed separately by GeoNames' postal code list, which does not list every code, so one it does not hold is not flagged.

Further reading: How to read an address-existence answer.

Check an address in South Korea

The same lookup the API runs, with South Korea already selected.

Live demo

POST /demo/address · no key needed

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Response

Look up any address to see the full API response, straight from the live service. The country decides which format it is read against.

Every field in the response Get your API key

The postal code

Postal codes in South Korea are five digits.

pattern \d{5}

A postcode list from a multi-country source is installed for South Korea, so a postal code here is not only checked for shape but looked up: 34,249 postal codes from GeoNames' postal code list, version 2026-10-31. It lists current codes only, so a retired code is not told apart from one it does not hold.

What South Korea calls an address that is not a front door

A PO box, a private mailbox and the other kinds of delivery point below are told apart by the words written on the address, never by a list of whose box is whose. An entry is carried for South Korea, so an address here with none of the words below answers street. The words themselves are international spellings, not the operator's own: no spelling from its addressing guide is held yet.

address_type	written as
private_mailbox Private mailbox at a mail-receiving agency	PMBinternational spellings the checker also reads
po_box Post-office box	PO BOX, P O BOX, POST OFFICE BOX, POSTBOXinternational spellings the checker also reads
general_delivery Held at the counter for collection	POSTE RESTANTE, GENERAL DELIVERYinternational spellings the checker also reads

What can be checked for an address in South Korea

Read from the datasets this server holds right now, not written into the page. For most countries the answer is the written form and the postcode shape and nothing beyond them — in particular not the row people assume is always there.

check	for KR	what the answer means
Written form	yes	The address is split into the country's own parts and rewritten in the order above. A missing required part is named in one typed reason rather than a general failure.
postal code pattern	yes	Checked against the pattern the table carries for South Korea. A value that does not match answers invalid_postal_code.
postal code exists	yes	34,249 postal codes from GeoNames' postal code list. It lists current codes only, so a retired code is not told apart from one it does not hold.
Kind of delivery point	yes	An entry is carried for South Korea, so an address with no marker answers street rather than unknown — though the words it holds are the international spellings, not the operator's own.
Street exists	no	No register is installed for South Korea, so a street is neither confirmed nor denied: match_level answers null.
Building exists	no	No address register is installed for South Korea, so exists answers null: not evaluated, never no. Absence is not evidence here.
Companies at the address	no	No open company register is installed for South Korea, so companies_registered answers null and no mail-drop conclusion is drawn from a count.
Known mailbox branch	no	No operator branch list covers South Korea, so is_mail_drop is never set from one here.
Post actually arrives	no	Not from this page, and not from open data in any country: whether post is delivered, and the vacant, residential and agency flags that go with it, are the postal service's own licensed product. Those fields answer deliverability_checked: false rather than a guess.

Null means not evaluated, never no.

Other countries

Sources

Google's Address Data Service · address-formats 2026-09-05© Google LLC, CC BY 4.0 (Google Address Data Service); initial import via commerceguys/addressing (MIT)
The postal operators' addressing guides · address-rules 2026-09-17
GeoNames' postal code list · geonames-postal-codes 2026-10-31Postal codes, places and centroids from GeoNames (geonames.org), CC BY 4.0.

Data synced on 2026-10-31: the newest version among the datasets listed above.

Wrong result, or is it about you? If this tool said something you think is wrong, tell us and a person reads it. If Spaw is holding data about you and you never signed up here — a customer may have had your address verified, or reported that a message to it bounced — erase it yourself, confirmed by mail to that address and with no account needed.

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