A network providing service to an end user may include a first client, a second client and a charging system. A method implemented by the network may include the first client receiving a service event that is destined for an end user and retrieving a first logical clock value from memory, where the first logical clock value specifies a number of service events received at the second client. The first client may increment a second logical clock value based on receipt of the service event and may construct a first time stamp parameter based on the first logical clock value and the second logical clock value. The first client may send a charging request to a charging system, where the charging request includes the first time stamp parameter and where the charging request requests credit authorization associated with providing the service event to the end user.