A Universal Call Identifier (UCID) is a unique tag that is assigned to a call. The purpose of the UCID is to allow call-related data to be collected and aggregated from multiple sources and multiple sites. The UCID can then be used to group all the data from various sources about a particular call.

When this feature is enabled on the communication server, CMS receives the UCID that is assigned to calls by the communication server. The UCID is then stored, along with data about the call itself, by the Call History feature, which includes either Internal or External Call History. The data is available to both Custom Reports and the Report Designer. UCID data is stored in the call history and agent trace tables.