Netherlands Postal Code Format Guide
Dutch postcodes use four digits, a space, and two uppercase letters. Together with a house number they can identify a small delivery segment; the letters I, O, and Q are generally excluded.
Standard format
NNNN AA
Example
1011 AB
Implementation and validation notes
Dutch postcodes use four digits, a space, and two uppercase letters. Together with a house number they can identify a small delivery segment; the letters I, O, and Q are generally excluded.
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 Netherlands postal code format?
A common representation is NNNN AA, for example 1011 AB. Dutch postcodes use four digits, a space, and two uppercase letters. Together with a house number they can identify a small delivery segment; the letters I, O, and Q are generally excluded.
How should Netherlands 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.