Is it legal to pay social security to former employees?

Illegal. Workers must sign labor contracts with employers and establish labor relations before they can pay social insurance through their employers. The two sides did not establish a labor contract relationship, but the agency paid the social security on their behalf, which is illegal and not allowed by the policy. There are different rules and requirements for participating in insurance as an individual, but there are usually household registration restrictions.

Legal objectivity:

Article 57 of the Social Insurance Law, the employing unit shall, within 30 days from the date of its establishment, apply to the local social insurance agency for social insurance registration with its business license, registration certificate or unit seal. The social insurance agency shall, within fifteen days from the date of receiving the application, examine and issue the social insurance registration certificate. Article 58 stipulates that the employing unit shall apply to the social insurance agency for social insurance registration for its employees within 30 days from the date of employment. China's "Provisional Regulations on the Collection and Payment of Social Insurance Fees" clearly stipulates that the social management department is responsible for the collection and payment of social insurance fees, and the employer must handle social insurance for workers according to law. If the employer has gone through the social security formalities for the employee, but the employer fails to pay the social insurance premium for the employee according to the regulations, regardless of whether the social insurance premium is unpaid or refused to be paid, the social management department can force the collection according to law.