Google Tez paired UPI payments by sound, so strangers could pay without sharing IDs

In 2017 India had roughly 300 million smartphone users but almost no NFC-equipped phones, so the contactless payment tools built for Western markets did not fit. Google's answer, Tez (Hindi for 'fast'), launched in September 2017 on top of the country's Unified Payments Interface (UPI), which linked 55 banks into one app.

Tez's signature move was 'Cash Mode' — an Audio QR technology that pairs two phones through an ultrasonic tone sent via the microphone and speaker. The sound identifies payer and payee, so neither person needs to exchange a bank account, phone number or UPI ID, and the feature works on any phone with a mic and speaker, no NFC chip required.

The design made digital transfers behave like cash: two people near each other could settle instantly and privately, which mattered in a market where entry-level phones dominate and after the government's 2016 high-value-note ban had pushed millions toward digital payments. Tez also organized transactions like chat conversations and let small businesses accept payments into their bank accounts.

Tez shipped on Android and iOS and was built 'India first', with Google planning to expand the model to other emerging markets; the audio pairing was later retired as Google rebranded Tez to Google Pay, but the launch had demonstrated how a payment product could adapt to the devices its users actually carried.