Social security can be used as evidence of work in a unit

Legal analysis: the record of payment of social insurance premiums can be used as evidence of employment in a unit. If the employer and the worker have not signed a labor contract, the following documents can be used to prove the existence of labor relations between the two parties: the recruitment record of the employer filled in by the worker; the wage payment vouchers or records; the documents issued by the employer to the worker to prove his/her identity; the attendance records; and the testimonies of other workers.

Legal basis: "Notice of the Ministry of Labor and Social Security on Matters Concerning the Establishment of Labor Relationships" Article 2 If the employer has not signed a labor contract with the worker, the following documents can be referred to in determining the existence of a labor relationship between the two parties: (1) the wage payment vouchers or records (the roster of employees' wage payment), the records of payment of social insurance premiums; (2) the "work permit" or "work card" issued to the worker by the employer. (b) Documents issued by the employing organization to the workers, such as "work permit", "service permit", etc., which can prove their identity; (c) "registration form", "application form", etc., filled out by the workers to recruit workers by the employing organization; (d) documents which can prove their identity. (c) Records of recruitment such as "registration forms" filled out by the workers; (d) Attendance records; (e) Testimonies of other workers. Among them, (a), (c), (d) of the relevant evidence by the employer to bear the burden of proof.