In case you login to the app using your mobile phones then your entire address book will be sent to the Truecaller servers. This is because, Facebook, Gmail and Yahoo! are the most widely used social networking sites that contain a lot of phone numbers and other contact details. It implies that when you use one of the social sites, your entire contacts including phone numbers, contact names, email ids will be uploaded to a secure Truecaller server. If you don't have one you cannot connect to Truecaller database.

If you have already used Truecaller, you might have seen that Truecaller only allows either Facebook, Yahoo! or Gmail to access Truecaller app. The story must start from the login screen. After going through several data matching/refining algorithms, this data is made available to all truecaller users to search upon. This data is then uploaded by the app to the company's servers. As part of the end user agreement, the truecaller app asks the user to allow access to the user's address book/contacts on the smart phone. The data is crowd-sourced from the millions of users who have downloaded the truecaller app on their smart phones. Now apparently everyone who has installed the app has surrendered his phone book. You want those unknown numbers then you have to part with your phone book contacts. Truecaller acts on a give and take scenario. So, did you ever wonder How Truecaller actually works? How does it know all the phone numbers and caller ids? How does Truecaller app work?

Today, many smart phone users are using Truecaller to trace out a lot of spam calls they get everyday. Today they stand as a company of 55 international minds coming from different corners of the world to make a service that stretches every remote place of the world. Started five years ago, Truecaller was an idea of two engineers who aimed to create something new in the world of technology. It lets you search for contact information (based on name or number), identify incoming calls, and block calls you don’t want to receive – so you never have to leave the service to find the right contact. Truecaller delivers an experience that goes beyond the limitations of today’s phonebook apps so that people always have access to the right information, people and businesses they need.

How to set up truecaller id