South Korea Postal Code Format Guide
South Korean postcodes use five digits. Road-name addresses are the current standard, although older lot-number addresses may still appear in legacy data.
Standard format
NNNNN
Example
03000
Implementation and validation notes
South Korean postcodes use five digits. Road-name addresses are the current standard, although older lot-number addresses may still appear in legacy data.
Validate required state, character set, length, and syntax on the client, then repeat validation on the server. Preserve the original input and normalize into a separate field; never truncate local scripts, compound names, or leading zeroes to fit a single Western assumption.
This guide describes common formats rather than an official registry and cannot enumerate every exception. Generated output is for testing only, not delivery, calling, identity verification, or real account activity.
Related resources
Frequently asked questions
What is the standard South Korea postal code format?
A common representation is NNNNN, for example 03000. South Korean postcodes use five digits. Road-name addresses are the current standard, although older lot-number addresses may still appear in legacy data.
How should South Korea postal code test data be stored?
Store the original value as a string so leading zeroes, spaces, hyphens, accents, and local scripts are preserved. Use a separate normalized field for search.
Does correct formatting prove the data is real?
No. Syntax validation cannot prove an address is deliverable, a number is assigned, or a name belongs to a real person.