What's the deal with social security requiring sequential filing

In the social insurance contributions for flexibly employed people, the contributors need to declare in a certain order. Contributors need to declare the previous year's social insurance contribution base first. This is to account for the amount of the previous year's social security contributions and to ensure that the contributors make contributions according to their actual income. Only after completing the declaration of the previous year's social security contribution base can the contributor declare the current year's social security contribution base. This ensures that the amount of social security contributions is determined according to the current year's income.