Inside Truecaller's biggest iPhone update: Product chief explains how live caller ID works in iPhone

Truecaller, the popular caller identification and spam blocking application, has recently announced a significant overhaul for its iPhone app, finally delivering a feature long-requested by users: real-time caller ID. This major update, made possible by recent API changes from Apple in iOS 18, promises to dramatically improve call identification accuracy and user experience on iPhones.

In an exclusive interview with Business Today, Nakul Kabra, Product Director, iOS at Truecaller, explained the transformative changes to Truecaller, highlighting the journey to achieve this milestone. He leads the development of Truecaller's iOS app, guiding its vision and strategy.

For years, Truecaller’s caller ID on iOS operated within the limitations of Apple's CallKit framework, introduced in 2016. As Kabra detailed, this previous system relied on downloading number lists onto the device for offline matching. "In 2022, when we rebuilt the app, we really harnessed the full power of that framework and tried to 10x, 20x, identify more calls on iOS, which significantly improved the whole product," he stated.

However, this offline approach had its limits. While effective at identifying many spam and business calls, it struggled with less frequently reported numbers, or calls from regular Truecaller users not in the downloaded lists. Kabra explained, "It was not enough because it was still not identifying all the calls… a lot of other calls, like a call from a regular Truecaller user or a call from some number which doesn't have enough spam reports and so on. Those calls were not being identified right away."

Truecaller actively shared this feedback with Apple, emphasising the need for real-time, server-based lookups, particularly for markets like India with vast user bases. "If we want to provide call identification, like real-time call identification, there has to be some kind of communication between the iPhone and the Truecaller servers at the time of the call to figure out who's calling. Because without that, it's not really possible," Kabra asserted.

Crucially, the new framework, introduced by Apple in iOS 18.2, allows for this real-time communication whilst maintaining a strong focus on user privacy – a core principle for both Apple and Truecaller. Kabra emphasised the privacy-preserving design throughout the conversation. "Even before our new update, the way we were powering caller ID on iOS, we were powering it without needing to know who the user is or who’s getting the call. Or from which number you're getting the call."

This commitment to privacy is further enhanced in the new "live lookup" system. Kabra outlined the three key pillars ensuring this:

• Apple's Private Relay: The operating system itself, after user permission, initiates requests to Truecaller servers via Apple's Private Relay, legitimising the request origin without revealing user identity to Truecaller.
• Privacy Pass Protocol: This confirms the user is a legitimate Truecaller user without requiring personal identification.
• Private Information Retrieval & Homomorphic Encryption: This advanced encryption allows Truecaller servers to perform the lookup without decrypting the number being searched. Decryption only happens on the iPhone, safeguarding call privacy.

"And these three things together make it completely bulletproof in terms of the privacy. And at the same time, this enables users to know who's calling them real time," Kabra summarised. The entire process, from call reception to caller identification, happens "in a flash of a second".

The update also extends to Voice over IP (VoIP) calls, including platforms like WhatsApp and FaceTime. "When we launched this live caller ID lookup, out of the box, it automatically supports all the VoIP apps," Kabra confirmed. Whilst blocking VoIP calls directly remains outside Truecaller's control, the app can now flag spam calls within these platforms, empowering users to make informed decisions.

When talking about telecom operators like Airtel and Jio, which offer similar spam filters, Kabra differentiated Truecaller's offering by its contextual depth and blocking capabilities. He explained Truecaller provides "very specific context" such as the nature of potential spam (eg. car insurance sales, fraud attempts), aiding users in discerning important calls from unwanted ones. Furthermore, Truecaller offers call blocking features, which Kabra noted, "is not a feature with the carriers as of today."

These new Truecaller features like real-time caller ID and enhanced spam blocking are behind a paywall, part of Truecaller’s premium subscription on iOS. This subscription costs ₹899 annually or ₹99/month, and could deter certain iOS users from getting access to the new features. However, Kabra reported strong initial adoption of the paid feature, noting a 30-day free trial is available for users to experience the new capabilities. He also highlighted the new family plan - which costs ₹1,490 annually (split between up to 5 people) as a cost-effective option.

Looking to the future, Truecaller is exploring further enhancements for iOS, including image-based caller ID to visually identify businesses or signal spam, and more granular user control over call blocking and SMS filtering. Kabra also hinted at bringing AI-powered call screening, already launched in the US, to the Indian market, showcasing Truecaller's ongoing commitment to innovation on the iPhone platform.

This latest update marks a pivotal moment for Truecaller on iOS, finally bridging the feature gap with its Android counterpart and providing iPhone users with a significantly more powerful and privacy-focused caller identification experience.