A vendor weighs vegetable next to an advertisement of Paytm, a digital payments firm, hanging amidst his vegetables at a roadside market in Mumbai, India. Image Credit: Reuters

Billionaire Vijay Shekhar Sharma, the founder and chief executive officer of India's biggest digital payments company, said he'll look to raise his stake as Paytm approaches profitability.

"There is never a day that I would not buy more equity in Paytm," Sharma told Bloomberg News in an interview on Monday. "The single largest shareholder of Paytm is now an Indian, that is myself, and I believe this is definitely a key milestone."

On Monday, Paytm unveiled a $12 device that allows customers to make payments by scanning a QR code or tapping cards on a reader, and alerts merchants when money is credited to their account. The machine accepts all major credit card networks, including homegrown RuPay.

With Paytm Card Soundbox, the company solves two problems for merchants - accepting card payments along with getting instant audio alerts for all payments. The launch of Paytm’s unique device will transform in-store payments by expanding payment acceptance for merchants by combining Soundbox with NFC or contactless debit and credit card payments with mobile payments.

"Audio payment alerts have transformed digital payments in India and enabled many merchants to seamlessly digitise their businesses. Paytm Card Soundbox is India’s first Soundbox that will also accept contactless card payments and would further accelerate cashless transactions in the country," said NPCI.

The new Soundbox will provide both audio and visual payment confirmation through an LCD display to the merchant and the customer.

Sharma became the biggest investor in Paytm, officially called One97 Communications Ltd., after he acquired shares from China's Ant Group Co., according to a disclosure on Sunday. Sharma holds 19.42 per cent of the company, replacing AntFin, which now owns 9.9 per cent.

The company's shares rose as much as 1.8 per cent Tuesday.

Paytm's monthly users jumped 20 per cent in July-August to an average of 94 million, it said in a statement Tuesday. Loan disbursements, a key growth metric, more than doubled to 107.1 billion rupees ($1.3 billion).