What is CTI?
CTI connects the phone system with the systems people work in, usually the CRM. The phone system reports every event: it rings, someone answers, nobody answers, the call ends. The CRM looks up the contact for the number, shows it while the phone is still ringing and logs an activity. In the other direction, a click on a number in the CRM starts the call. The most important effect is unspectacular: the missed call becomes a task with a name instead of vanishing into the call log of one device.
Technically there are two routes. Cloud phone systems usually come with ready-made integrations for common CRM systems or send every call event via webhook to an address you choose. Older on-premises systems connect to individual computers through standard interfaces such as TAPI. For small teams the first route is almost always the simpler one, because it needs no extra software on every workstation.
CTI only sees what runs through the phone system. Calls to private mobiles, via WhatsApp or to a second number stay outside, and with a withheld number there is no contact to match. Recording calls is not automatically part of it either: storing the number in the CRM to handle an enquiry is different from recording a conversation, which in Germany is a criminal offence without authorisation under section 201 of the Criminal Code.
Why does CTI matter?
CTI captures only part of all conversations, and that part is shrinking. According to the annual report of Germany's Federal Network Agency of 5 June 2026, around 132 billion call minutes ran over mobile networks in Germany in 2025 and 47 billion over fixed lines, but 198 billion over messenger and video services, more than half. Anyone introducing CTI therefore also needs a rule for how calls from the other channels get into the same list.
CTI in practice
- 01At a trades business every missed call appears as a task in the CRM, assigned to the person on phone duty that day.
- 02When an existing client calls an agency, the CRM shows the name and the current project while the phone rings, and after the call the note sits on the right contact.
- 03A team without a ready-made integration has its cloud phone system send a webhook for every missed call, which adds a row to a shared list.
