The employing unit shall truthfully report to the local tax authorities the social insurance payment base of the insured employees in the next social security year according to the average monthly salary of the insured employees in the previous year. The social security payment base is fixed for one year and cannot be changed within one year. The calculation caliber of employee payment base should be strictly in accordance with the Provisions on the Composition of Total Wages issued by the National Bureau of Statistics in June 1990 1. The total wage consists of six parts: hourly wage, piece-rate wage, bonus, allowance and subsidy (except for travel allowance, missed meal allowance and one-child allowance), overtime wage and salary paid under special circumstances. The employing unit shall truthfully declare the average monthly salary of employees in the previous year. Newly insured employees (new employees of this unit, not employees who have never been insured) take the starting monthly salary as the payment base.

As for the base number of five insurances in social security, there are fixed upper and lower limits, which are specified by the municipalities according to the actual situation. Generally speaking, it is not lower than the local minimum wage, and the upper limit is 300% of the local social security wage. Medical insurance is special, and many places stipulate that it should not be less than 60% of the local social security salary.