1, people who pay social security also have to file tax returns;
2. The basis of social security payment is the same as that of individual tax payment, both of which are wages;
3. After the integration of the five certificates, the relevant information of social security and individual tax will be cross-reviewed.
Legal basis: Article 58 of the Social Insurance Law, the employer shall apply to the social insurance agency for social insurance registration for its employees 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. 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.