Call overflow
Call overflow is the routing of incoming calls to a secondary destination (another team, an outside answering service, or an automated system) when the primary destination is busy, unstaffed or not answering within a set time.
Also called: overflow routing, overflow handling
A phone system is told what to do when the first choice cannot take a call: after a number of rings, when every line is in use, or outside opening hours. The overflow destination might be a second office, a mobile, a queue, voicemail, or a third-party service that answers on the business’s behalf.
Overflow is what turns a missed call into an answered one without adding staff. It is also where the caller’s experience most often breaks, because the overflow destination usually knows less than the primary one.
Overflow answering as a service, a provider that takes only the calls a business cannot, is a category in its own right.