Apple Pay transactions grew 450 per cent in the 12 months to end-March, CEO Tim Cook revealed in the company’s latest earnings call.

Its mobile wallet service is currently available in 15 markets following launches in Taiwan and the Republic of Ireland during its fiscal Q2 – the period ended 31 March.

Cook said the app could now be used in a potential 20 million contactless-equipped merchants, some 4.5 million of which are based in the US.

The company does not break-out profit or revenue from Apple Pay in its results and did not offer a complete market by market breakdown of its performance. However, it did highlight strong growth in acceptance of the product in the UK and Japan.

In the year to end-March, transactions in the UK grew 300 per cent while the number of locations accepting the payment method increased by 44 per cent. In Japan, where the service launched in October with a focus on public transport payments, it is now recording 20 million transactions per month on transit services spread across 500,000 users.

“Apple Pay is experiencing phenomenal traction,” Cook said.

Juniper Research in April predicted Apple Pay user numbers will almost double during 2017 to 86 million around the world.