1. tax returns, tax receipts, payment letters

2. Social insurance declaration form and payment book

3 proof of income tax and value-added tax paid by the unit.

4 proof of social security funds, including the proof that the unit has entered the social security account.

Components of social security funds:

1, endowment insurance: a system that provides basic living security for employees after retirement;

2. Medical insurance: used to reduce the burden of medical expenses when employees and their families are sick;

3. Unemployment insurance: providing basic living expenses and employment services for unemployed workers in a certain period of time;

4. Work-related injury insurance: provide medical expenses and living allowances for employees who are injured at work or suffer from occupational diseases;

5. Maternity insurance: to provide certain economic subsidies and safeguard measures for the maternity of female employees.

To sum up, the proof of paying taxes and social security funds according to law includes tax return forms, tax stamps, payment books, social insurance return forms, payment books, income tax and value-added tax paid by the unit, and proof of social security funds, such as the proof that the unit entered the social security account.

Legal basis:

Regulations for the Implementation of the Individual Income Tax Law of the People's Republic of China

Article 45

Individual income tax returns, individual income tax withholding reports and individual income tax payment vouchers shall be uniformly formulated by the competent tax authorities of the State Council.

Interim Regulations on the Collection and Payment of Social Insurance Fees

Article 7

Payment units must apply for social insurance registration with local social insurance agencies and participate in social insurance.

The registered items include: unit name, domicile, business place, unit type, legal representative or person in charge, account number of the bank where the account is opened, and other matters stipulated by the administrative department of labor and social security of the State Council.

Article 8

Enterprises shall apply for social insurance registration at the same time when registering.

Payment units other than those specified in the preceding paragraph shall, within 30 days from the date of establishment, apply to the local social insurance agency for social insurance registration.

Article 9

If the social insurance registration items of the payer are changed or the payer is terminated according to law, it shall, within 30 days from the date of change or termination, go through the formalities of change or cancellation of social insurance registration at the social insurance agency.

Article 10

Payment units must declare the amount of social insurance premiums payable to social insurance agencies on a monthly basis, and pay social insurance premiums within the prescribed time limit after being approved by social insurance agencies.

If the payer fails to declare the amount of social insurance premiums payable in accordance with the regulations, the social insurance agency shall temporarily determine the amount payable according to 110% of the amount paid by the unit last month; If there is no amount paid last month, the social insurance agency shall temporarily determine the amount payable according to the operating conditions of the unit and the number of employees. After the payer completes the declaration procedures and pays the social insurance premium according to the approved amount, the social insurance agency shall settle the account according to the regulations.

Labor Law of the People's Republic of China

Article 74

Social insurance fund handling institutions shall, in accordance with the law, manage and operate social insurance funds, and shall be responsible for maintaining and increasing the value of social insurance funds.

Social insurance fund supervision institutions shall supervise the income and expenditure, management and operation of social insurance funds in accordance with the law.

The establishment and functions of social insurance fund handling institutions and social insurance fund supervision institutions shall be prescribed by law.

No organization or individual may misappropriate social insurance funds.