Bharti Airtel has said it will mark suspected spam calls and messages for all smartphone users on its network from September 26.

Airtel CEO Gopal Vittal told journalists that the company had been working in “confidential stealth” for a year to develop this solution, which he said had accurately flagged 97% of spam calls and over 99% of spam texts during testing by the company, by analysing the behaviour of the suspected spammers.

Flagged calls will have “Suspected Spam” as the caller name on smartphones, and suspected spam texts will have the same term prefixed before the SMS.

The announcement comes as the Telecom Regulatory Authority of India imposes even more stringent regulations to block spam callers and SMS senders, such as by enforcing regulations that commercial calls be restricted to a 10-digit series that starts with the prefix 160.

Mr. Vittal said that Airtel’s solution would also detect calls made by spammers using personal mobile handsets, something that has been a challenge for telcos due to SIM cards being regularly changed by spammers and scammers.

The official said Airtel had written to other telecom operators seeking cooperation on sharing information on business users, so that their calls are not incorrectly flagged as spam.

While he did not announce that the technology would be shared with rival telecom operators, he said that the firm would have “no issue” sharing the database used by its proprietary model to detect spam calls. He added that other solutions would require users to have Airtel’s app installed (which only 35% of its users have done) or have other apps such as Truecaller installed. 

Since 2007, TRAI and government officials have tried to apply pressure on telemarketers and cyber fraudsters who make phone calls and commit frauds via SMS, and over the years these attempts have escalated steadily. From a do-not-disturb registry launched over a decade-and-a-half back to requiring all transactional and promotional SMS formats to be registered on a blockchain solution, regulations have still struggled to keep up with an onslaught of spam, due to the variety of techniques employed to place them. 

India is “number four in spam calls being made,” Mr. Vittal pointed out, adding that over 60% of the company’s customers received at least three such calls a day. While financial frauds are a key priority for anti-spam efforts, he said that “this is about intrusive communication,” pointing out that even legitimate business and advertising calls could be a menace.