WhatsApp has won regulatory approval to double the number of users on its payments service in India to 40 million, a source with direct knowledge told Reuters. The company had requested that there should be no cap on users of its payment service in India.

Instead, the National Payments Corporation of India (NPCI)this week told the company it could double the user base to which it can offer its payment service - currently restricted to 20 million - the source said.

The source said the new cap would still hinder the company's growth prospects given that WhatsApp's messenger service has more than 500 million users in India, the company's biggest market.

WhatsApp competes with Alphabet Google Pay, SoftBank- and Ant Group-backed Paytm and Walmart’s  PhonePe in India's crowded digital market.

The NPCI gave WhatsApp approval to start its payments service last year after the company spent years trying to comply with Indian regulations, including data storage norms that require all payments-related data to be stored locally.

WhatsApp has almost reached its user base of 20 million for payment services, said the source, who declined to be identified as the details are private.

Online transactions, lending and e-wallet services have been growing rapidly in India, led by a government push to make the country’s cash-loving merchants and consumers adopt digital payments.

WhatsApp Pay was announced last year in India as a means to make UPI based payments directly from the WhatsApp app. The feature was brought in to make sending money to friend and family easily. The service had initially struggled to take off but over the time, it gained traction.

WhatsApp continues to add more features every few months to make the texting experience better. Recently, it added the ability to join a group video chat in any WhatsApp group directly. The app also received a couple of design updates, including some tweaks to the floating windows for picture-in-picture feature.