In computer telephony an automatic dialler (shortened to an auto-dialler or more simply in context just a dialler, and also known as an outbound dialler) is a computer system that makes outgoing calls from a call centre to customers from call agents based upon a loaded list of contacts. Whereas automatic call distribution (ACD) distributes inbound calls to a call centre amongst its agents, an auto dialler makes outbound calls and comes in several forms. Auto diallers are responsible for providing management information to call centre operators, including how many outbound calls each agent has handled. In more sophisticated computer telephony systems, a single system handles both ACD of inbound calls and dialling of outbound calls, allowing agents to be switched between the two as traffic volumes require.
In their earlier forms, diallers would be proprietary standalone systems that connected directly to a private branch exchange or even to the public switched telephone network. However, with the advent of customer-owned switching equipment providing call-control interfaces, diallers shrunk to being external adjunct systems that controlled existing switches.