Member Check

UTN has a system to check if a person is a member or not. This system uses the unions new member system (MELOS).

The member check can be found at


The member check is also available as an api and can be used from a website, app etc. To use the api, send a POST request to


In the POST request, you must send the social security number (personnummer) of the person you want to perform a member check on. The social security number can be either 10 or 12 digits. A dash (-) is optional. The social security number must be sent in the ssn parameter. Example:



The response will always have the form of a JSON string. The http status code will also be set accordingly. The various responses are described below


Http Status Code: 200

Response: {is_member: true|false};


Internal server error

Http Status Code: 500

Response: Empty


Bad request

Http Status Code: 400

Response: {code: error_code, message: "A message describing the error"}

The following error codes exist:

  • 1 - The ssn parameter is missing
  • 2 - The ssn parameter is empty
  • 3 - The ssn is badly formated