Do I need a certificate from my previous company to pay social security for changing companies?

Legal analysis: Yes. When a new company transfers to social security, it needs a certificate of resignation. After the employee resigns, the employer shall handle the resignation procedures and social security transfer procedures for the employee. After leaving the company, the original company will reduce the number of employees from its company account, and then the workers can continue to pay social insurance as freelancers themselves, or they can transfer to the new company account to let the new company continue to pay social insurance.

Legal basis: People's Republic of China (PRC) Social Insurance Law.

Article 57 An 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. Where the social insurance registration items of the employing unit are changed or the employing unit is terminated according to law, it shall, within 30 days from the date of change or termination, go to the social insurance agency to handle the change or cancellation of social insurance registration. The market supervision and management department, the civil affairs department and the organization management organ shall promptly inform the social insurance agency of the establishment and termination of the employing unit, and the public security organ shall promptly inform the social insurance agency of the birth, death, household registration, migration and cancellation of the individual.

Article 58 An 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.