Millions of commuters in Hong Kong and Shenzhen will be able to use a single pre-paid card to pay public transport fares and make small purchases in the two cities starting later this year.

A card with two chips — integrating the Octopus card and the Shenzhen Tong smart card — will be introduced, Hong Kong Monetary Authority Chief Executive Norman Chan Tak-lam said Tuesday (Jan 26).

The use of cash-free transactions would in future be expanded to the entire Pearl River Delta region, he said. Speaking at a forum on integration between Hong Kong and the Delta region, Chan said a "two-in-one card," with chips for the Octopus card and Shenzhen Tong, or known as TransCard, was technically simple.

"But there is a need to issue new cards and tackle the issue of value uploading involving different currencies," he said. Another feasible proposal would be development of a common card reader for use in Shenzhen and Hong Kong, including the Octopus card and Shenzhen Tong.

There are more than 20 million Octopus cards in circulation in Hong Kong, while 6.5 million Shenzhen Tong cards have been issued.

More than 90 million HKD (12 million USD) worth of transactions are made each day with Octopus cards, but they are accepted only at 11 fast-food outlets in Shenzhen and four duty-free shops at Luohu and Huanggang checkpoints.

Chan said mutual use of e-money in Hong Kong and the Pearl River Delta region would be conducive to creating a world-class Delta metropolis.

Tan Gang, vice president of Shenzhen-based think tank China Development Institute, said integration of stored-value cards would bring huge convenience for cross-border travelers.

"It will encourage more Shenzhen residents to travel to Hong Kong and stimulate consumption there," he said. "It will also serve as a new platform for further cooperation between Hong Kong and Shenzhen."

Visitors to Hong Kong from the mainland are among the top spenders, parting with an average of 5,676 HKD last year, compared with 5,439 HKD overall for overnight visitors, 2,138 HKD for same-day visitors and 1,498 HKD for all visitors, according to the Hong Kong Tourism Board.

Octopus Holdings has been studying a possible merger with the Shenzhen smart card since 2008, but little progress has been made due to technical and operational obstacles, while there are also concerns over currency exchange.

The company's chief executive, Prudence Chan Bik-wah, said last year that putting both chips in one card could cause the systems to interfere with one another. But a company spokeswoman said there had been breakthroughs. "We still need to perform tests over the next few months on the new card's technical viability."