"The set-up of Douyin Pay is to supplement the existing major payment options, and to ultimately enhance user experience on Douyin," Douyin said in a statement.
Users of Douyin, which accumulated 600 million daily active users, previously could use Ant Group's Alipay and Tencent Holdings' WeChat Pay, the country's two ubiquitous third-party mobile payment channels, to buy virtual gifts for livestreamers or items from shops on the platform.
ByteDance founder and CEO Zhang Yiming built up the company's payment capability in China by acquiring Wuhan Hezhong Yibao Technology Co last year. Hezhong Yibao obtained a third-party payment license from the central bank in 2014.
ByteDance has been ordered by the outgoing Trump administration to divest TikTok's U.S. assets on national security concerns.
The company, which denies the allegation, has been in talks for months with Walmart Inc and Oracle Corp to shift such assets into a new entity.
Douyin is the main revenue generator for ByteDance. It provides a glimpse of what TikTok could eventually become, as Douyin started selling merchandise in 2017 and now operates a growing e-commerce operation where hundreds of millions of users shop on a daily basis.
ByteDance's expansion comes as China's financial regulators are tightening oversight over financial technology firms, particularly companies such as Ant Group.
China's third-party payment sector is dominated by Alipay and WeChat Pay, with the former taking 55.39per cent of the total market in the second quarter of last year, according to market researcher Analysys. Other players include JD.com's JD Pay, Baidu Wallet and Meituan Pay.
(Reporting by Yingzhi Yang in Beijing and Brenda Goh in Shanghai)