China’s central bank fined Alipay, Gopay and Union Mobile Financial Technology (UMF) for violating financial service rules as it continues to clamp down on the activities of third-party payment providers, Xinhua reported.

Alipay received the lowest of the three fines levied by the People’s Bank of China: CNY4.12 million ($603,202) for “violating payment service regulations”. Gopay and UMF’s charges related to failing to conduct sufficient customer identification checks, while UMF was also found to have broken rules related to foreign exchange.

In addition to the fines of CNY24.3 million for Gopay and CNY14.32 million for UMF, the two had a combined total of CNY34.3 million in “illegal gains” confiscated.

The announcements are the latest in a spate of charges levied on companies after authorities began tightening regulation on digital financial services and payment providers in China during 2017.

New rules include data regulations, money storage regulations and mobile application transactions limits for some customers.