Authentication uses the “key” parameter followed by the customer’s API key. All requests must be made over HTTPS.


Use your own API Key

Throughout our documentation you can use your own API key wherever you read YOUR_APP_KEY to run the examples we provide. Simply sign up for a free trial and enter the key when prompted. The key automatically populates the examples, so you only need to do this once.

Currently your app key is set to: [[app:key]]


As a user of our APIs you are currently free to use encrypted (https) or unencrypted (http) requests. We always advocate using encrypted connections where possible, though acknowledge that there are legitimate and justified use cases for not using encryption.



Ordnance Survey APIs no longer support calls made using SSL v2/v3 or TLS v1.0/v1.1.
All calls made to any of our APIs must support TLS v1.2 as of 24th October 2018 in line with current cyber security recommendations.
More information can be found on our dedicated support page.


All requests must be encoded correctly according to standard percent-encoding procedures for a URI.

What are the response codes?


Official description

Explanation in context of the API



Request has been successful.


Not Modified

In response to a conditional GET request this response indicates that the underlying data has not changed since the previous request, and cached results may be re-used.


Bad Request

E.g. missing query parameter, malformed syntax.



The client has not provided authentication or incorrect authentication.


Not Found

The server has not found anything matching the Request-URI.


Method not allowed

Request used an unsupported HTTP method, e.g. DELETE or PUT.


Internal Server Error

Generic internal server error.


Service unavailable

E.g. due to overloading or maintenance.

Service Checks


Before you Check the Service

In order to check the Os Places API service you will need an API key with a valid Os Places package plan. This can be purchased through your account portal.

To check that the service is running correctly, copy one of the below URL's and paste it into your browser along with your API key;