Callback is a low-cost telephone service for mobile and fixed- network telephony offered by telecommunications providers. With this service, the telecommunications provider switches a low-cost or toll-free connection via a callback. The callback service is switched by connection network operators who are not network operators of the telephone connection.
To activate the callback service, the interested party must call a toll-free number of the provider and leave it for one or more rings. He can then hang up again. The provider has determined the subscriber's call number from the call, which the subscriber must not suppress by means of caller ID suppression, as otherwise recognition is impossible. The telecommunications provider then dials the subscriber and provides him with a toll-free connection. The subscriber can now enter the complete phone number and establish the connection to the communication partner.
In addition to classic callback, there is automatic callback and Web-basedclick-to-callback. With automatic callback, which is often used in call centers, the connection is established as soon as a free line is available. Once the connection to the callback number is established, the telephone system sends a corresponding signal to the caller. Click-to-callback works in a similar way. The difference is that a customer has stored the callback number in the browser.