Lee's enterprise has benefited from the mainland's Internet Plus strategy, sufficient investment and large market. It has over 1 million merchant partners and over 50 million customers.

The company has also partnered with Tencent's WeChat pay and Alibaba's Alipay to extend mobile payment from China to Japan and countries involved in the Belt and Road Initiative.

"I think Hong Kong's greatest value is that it functions as a bridge," he says.

"We know how to work in an international environment in terms of managing customer relationships and understanding different business models."

Hong Kong Professionals (Beijing) Association founder Eric Fung encourages young Hong Kong residents to move to the mainland because innovation is the core driver of sustainable development in both places.

"The mainland possesses a large market, and rich scientific and technological talent, while Hong Kong is endowed with a highly developed education system and historically entrepreneurial environment," he says.

"Both will increase prosperity and innovation by combining their strengths."

Contact the writer at zhangzefeng@chinadaily.com.cn