Legal analysis: the upper limit is 300% of the average social wage of last year, and the lower limit is 60% of the average social wage of last year. Calculation of social security payment base: it is approved in April every year according to the average income of employees in the previous year, and the base remains unchanged from April of that year to March of the following year. The upper limit of pension, unemployment, work injury, maternity and medical insurance is 300% of the average social wage of last year, and the lower limit is 60% of the average social wage of last year. 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.

Legal basis: Article 8 of the Administrative Provisions on the Declaration and Payment of Social Insurance Fees The employing unit shall register social insurance for employees and declare and pay social insurance fees within 30 days from the date of employment. If the social insurance has not been registered, the social insurance agency shall verify the social insurance premium it should pay. If the employer fails to declare the amount of social insurance premiums payable according to the regulations, the social insurance agency shall temporarily determine the amount payable according to 1 10% of the amount payable by the unit last month, and the social insurance agency shall temporarily determine the amount payable according to the operating conditions of the unit, the number of employees and the average salary of local employees in the previous year. After the employer completes the declaration procedures, the social insurance agency shall settle the accounts in accordance with the provisions.