Dubbed Truecaller Voice, the company said its VoIP service offers a clear, crisp and high-quality call even when data or WiFi coverage is low.
"Integrating free calls into Truecaller on Android means fewer apps taking up space on your phone," the company said.
Truecaller said its users are making more than 180 million phone calls through the Truecaller dialer per day.
Half of the calls are to other Truecaller users, which is why the company has decided to launch its own VoIP service.
"For quick access to make free calls, the Truecaller Voice icon has been integrated into convenient places within the app such as your call logs, SMS Inbox, contact profile and after call screen," it said.
This enables users to access the VoIP call anywhere within the Truecaller app without switching to other applications.
The service is currently rolling out to Android users and will be launched for iOS users in future.