Protocol Basics

The Prepaid Utility Service Interface is an HTTP-based protocol. A detailed description of the supported operations and definitions can be found in the Specification section. Requests and responses contain information in the HTTP header and - depending on the operation - a JSON message body.


All communication must be secured by establishing an SSL encrypted transport. Basic HTTP authentication is be used to authenticate clients with the service, and is required for all requests.


The outcome of a request is determined by examining the HTTP status code of the response and, in the case of an error, a description contained in a JSON body.

Status type

Three outcomes for a transaction are possible and can be classed as follows: successful, unknown, and failed. HTTP status codes fall under one of the possible outcomes as indicated below.

HTTP Status Codes Status type
200, 201, 202 successful
500, 504, timeout unknown
400, 501, 503, all others failed

A timeout occurs when the client has not received a response to a request after the agreed upon interval. Unless otherwise agreed, this interval shall be 60 seconds. Any response received after the timeout should be logged but otherwise ignored.


In addition to the HTTP status code, non-successful response bodies contain an ErrorDetail object, if possible, to describe the failure in more detail. It should be noted though, that responses in some failure scenarios will contain an empty response body, and therefore no ErrorDetail object will be present.