Postalcode check

Validate Dutch addresses in the checkout

The API validates and complements filled-in postal code data for addresses located in The Netherlands. Therefore, you will always use the right address and prevent inconvenience during delivery.

Why use the Postalcode check API

  • User experience

    Postal code data is validated real-time, simplifying and accelerating the order process for a better user experience for customers, less return shipments and a higher conversion rate.

  • Correct data structure

    To provide the most recent and complete address data.

  • Easy to use

    No need to fill in addresses completely in your checkout form. Entering postal code and house number is sufficient to automatically complete an address with street and city.

Get started

View all the necessary information for implementing this API


View our exhaustive documentation.


All of our API's available as Postman collections.


Find PostNL on Github.


Test your integration by copying the endpoint.


Learn more about the Postalcode check API guidelines.