What is the difference between social security declaration salary and payment base?

Different definitions, different calculation methods.

1, declared salary refers to the amount of wages declared by the employer in accordance with state regulations when reporting the social insurance contributions of the insured employees to the social security agency. The payment base is the social insurance payment base determined by the social security agency according to the relevant national laws and policies and the average monthly salary of employees in the previous year.

2. The declared wages are declared by the employing unit according to the actual wages of employees, and the payment base is calculated according to the average monthly salary of employees in the previous year.