Regulations requiring foreign workers in China to enroll in its social security system are now in effect but the situation is complicated by differing levels of compliance and enforcement by local authorities. In cities that are enforcing the new regulations, employers are responsible for registering all foreign staff and ensuring that social security contributions are made on a timely basis. Failure to do so will result in fines and possibly rejected work permit applications. In other cities, participation is on a voluntary basis until further local regulations are issued.