Does the company stipulate that employees can not pay social security?

Employees who can't pay social security include: part-time employees, interns, contract workers, part-time employees of dependent workers, labor dispatchers, business personnel of self-employed outsourcing enterprises, co-insured, employees who leave their jobs without pay, and re-employed retirees.

legal ground

Article 58 of the Social Insurance Law

The employing unit shall, within 30 days from the date of employment, apply to the social insurance agency for social insurance registration for its employees. If the social insurance has not been registered, the social insurance agency shall verify the social insurance premium it should pay. Employees-free individual industrial and commercial households who voluntarily participate in social insurance, part-time employees who do not participate in social insurance in the employing unit and other flexible employees shall apply to the social insurance agency for social insurance registration. The state establishes a national unified personal social security number. Personal social security number is a citizen's identity number.