Hotline

In telecommunication, a hotline (also called an automatic signaling service, ringdown, or off-hook service) is a point-to-point communications link in which a call is automatically directed to the preselected destination without any additional action by the user when the end instrument goes off-hook. An example would be a phone that automatically connects to emergency services on picking up the receiver.

True hotlines cannot be used to originate calls other than to preselected destinations. However, in common or colloquial usage, a "hotline" often refers to a call center reachable by dialing a standard telephone number, or sometimes the phone numbers themselves. This is especially the case with 24-hour, noncommercial numbers, such as police tip hotlines or suicide crisis hotlines, which are manned around the clock and thereby give the appearance of real hotlines. Increasingly, however, the term is found being applied to any customer service telephone number.