Free tool

Free Dutch Postcode API

Look up the city and street for a Dutch postcode and house number. Free to use, no API key, no sign-up. Built and hosted on our own infrastructure.

Free forever No API key required No rate limit (for now)

Endpoint GET https://postcode.api.daltcore.com/v1/addresses

Try it in your browser

This is an early, unrestricted release. A rate limit may be introduced later as usage grows.

Example request

GET https://postcode.api.daltcore.com/v1/addresses
    ?postcode=8261AA&houseNumber=1

Example response

{
  "street": "Klokkensteeg",
  "city": "Kampen",
  "municipality": "Kampen",
  "district": "Kampen",
  "neighbourhood": "Binnenstad Kampen",
  "lon": 5.918772239519917,
  "lat": 52.55676280656684,
  "status": "Verblijfsobject in gebruik",
  "active": true
}

Reference

Parameters and response

Two query parameters, one JSON response. That is the entire API.

Query parameters

Parameter	Type	Description
`postcode`	string	Dutch postcode, 4 digits + 2 letters, no space (e.g. 1234AB).
`houseNumber`	integer	House number, digits only.

Response fields

Field	Description
`street`	Street name.
`city`	City or place name.
`municipality`	Municipality (gemeente).
`district`	District (wijk), per the CBS Wijk- en Buurtkaart.
`neighbourhood`	Neighbourhood (buurt), per the CBS Wijk- en Buurtkaart.
`lon`	Longitude (WGS84).
`lat`	Latitude (WGS84).
`status`	Official BAG registration status of the address.
`active`	Whether the address is currently active.

Errors

Status	Error	Meaning
`400`	`invalid_postcode`	Postcode is not a valid Dutch postcode (4 digits + 2 letters).
`404`	`not_found`	Postcode is valid, but no address exists for it and this house number.

Data source

Built on official Dutch government data.

Addresses come from Kadaster BAG, area boundaries from the CBS Wijk- en Buurtkaart. Both are official open government datasets, kept in sync automatically.

9.6M Addresses covered

Every registered address in the Netherlands (Kadaster BAG).

Monthly BAG refresh

Address data refreshes automatically every month.

Yearly Wijk/buurt refresh

District and neighbourhood boundaries follow CBS's own yearly publication cycle.

Need more?

Questions, feedback or a use case that needs more?

Get in touch. We are curious what you build with it.

Contact DALTCORE

Email: info@daltcore.com
Phone: 038 202 28 59
Location: Kampen, the Netherlands

All systems operational

Infrastructure monitored 24/7.