The rumors were true: Apple Pay is officially launching in China beginning today. Apple CEO Tim Cook broke the news on Chinese social network Weibo, and the company also updated its developer website with a small announcement.

“You can now support Apple Pay for your customers in China, providing an easy, secure, and private way for them to pay using their China UnionPay credit and debit cards,” the developer page explains. “Apple Pay lets users buy physical goods and services within your app without having to enter payment or contact information.”

According to the BBC, “as many as 20 China-based lenders will be supporting Apple Pay,” though it’s unclear who are among the first. The Indsutrial and Commerical Bank of China earlier this week suggested that it would support the service at launch.

Apple Pay is particularly compelling in China because the market has so many consumers who are already used to paying with their phones, a number that exceeds the population of the United States. That could mean big business for Apple.