---
title: "Boundaries of all postal code areas as GeoJSON"
method: GET
path: "/api/v1/postal-codes"
tags: ["Places"]
---

# Boundaries of all postal code areas as GeoJSON

`GET /api/v1/postal-codes`

## Request

- Base URL: `https://suomiatlas.com`
- URL: `https://suomiatlas.com/api/v1/postal-codes`
- Auth: one of:
  - none
  - HTTP bearer

A GeoJSON `FeatureCollection` of postal code area boundaries, for drawing a map. Large nationally — scope it to one municipality with `kunta`.

Example request: https://suomiatlas.com/api/v1/postal-codes?kunta=091

## Query parameters

- `kunta` string

## Response `200`

Boundaries.

- GeoJsonFeatureCollection
  - `type` 'FeatureCollection', required
  - `features` GeoJsonFeature[], required
    - `type` 'Feature', required
    - `geometry` object, required: A GeoJSON geometry object, in practice a Polygon or MultiPolygon in WGS84. Left free-form deliberately: the API applies no geometry-type validation, so a stricter schema here would promise a guarantee that does not exist.
    - `properties` GeoJsonProperties, required
      - `postalCode` string, required
      - `name` string, required
      - `municipalityCode` string, required
      - `maakuntaCode` string, nullable, required: Nullable, unlike its siblings: the municipality-to-region mapping is ingested separately from the geometry, so an area can legitimately have no region yet.

## Other responses

- `400`: A parameter was missing, malformed, or outside what this operation accepts. The message names the parameter.

---

[API](https://skmtc.dev/suomiatlas/apis/suomiatlas-read-api.md) · [All operations](https://skmtc.dev/suomiatlas/apis/suomiatlas-read-api/llms.txt) · [OpenAPI document](https://skmtc.dev/suomiatlas/apis/suomiatlas-read-api/revisions/b2627414938d?raw)