DID

DID stands for Direct Inward Dialling, also spelled Direct Inward Dialing. It is a telephone number that allows an outside caller to reach a destination within a business telephone system without first asking a switchboard operator to transfer the call. The destination might be an individual extension, a team, an automated menu or another configured route.

A DID is a numbering and routing concept rather than a physical telephone line. Multiple numbers can share underlying network capacity, and one number can route to different destinations according to a system's configuration. Having a DID does not imply unlimited simultaneous calls or permission to present that number on every outbound network. Businesses should consider the number's country, type, ownership arrangements and inbound routing separately from the connection used to carry calls. When moving providers, portability and continuity planning matter because customers may already rely on the published number as their contact point.