WhatsApp, which has more than a billion users a day, is trialing "immediate bank to bank transfer with UPI". UPI, or Unified Payments Interface, is a payments system run by the Reserve Bank of India, which appears to confirm reports that the payments service would be coming to India first.

It is not clear when WhatsApp payments might be made available in the UK.

An initial release in India, where WhatsApp has been recruiting local payment app experts, would give around 200 million users the ability to transfer money through the app.

WhatsApp refused to comment on its future plans for WhatsApp Payments, but said: "India is an important country for WhatsApp, and we're understanding how we can contribute more to the vision of Digital India. We're exploring how we might work with companies that share this vision and continuing to listen closely to feedback from our users."