Individual industrial and commercial households without employees, part-time employees who have not participated in the basic old-age insurance in the employer and other flexible employees can participate in the basic old-age insurance, and individuals pay the basic old-age insurance premium.
Therefore, if there are employees, they must participate in social insurance. Only the requirements for individual industrial and commercial households are generally lax.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.