WMS API

From the dataset abstract

The postal code areas of Helsinki metropolitan area has been produced at HSY together with the cities of Helsinki, Espoo and Vantaa. The data contains precise area boundaries and information on postal codes and offices.

The postal code area boundaries have been produced largely on the basis of the municipalities’ own boundaries, which means that they are compatible with the municipalities’ own postal code area boundaries. The accuracy of the harmonized material varies slightly by municipality due to the source data and maintenance practices. Postal code areas are not linked to administrative divisions, so they are located across several municipalities in some places. The data contains information on postal codes and post offices. In addition, the reference names of the areas have been added to the material from Statistics Finland’s open postal code area data.

Data cut with the coastline is also available for 2019 and 2022. This is better suited for visualizations where you do not want to include sea areas. The cut has been carried out using the sea material of the regional map.

The datasets have been completed at the beginning of each year.

Source: Pääkaupunkiseudun postinumeroalueet