Nanjing social security must have an employment permit.

Legal analysis: Nanjing foreign hukou needs employment certificate to pay social security, and the employment and entrepreneurship certificate is provided by the first company.

Legal basis: Article 5 of the Measures of Nanjing Municipality for the Administration of Employment and Unemployment Registration, the employing unit shall sign a labor contract, handle the employment registration within 30 days from the date of employment, and provide the following materials:

1. Copy of labor and social security registration certificate 2. Table 3 of Nanjing Employment Registration. Nanjing employment registration personnel roster 5. Text of labor contract. Other materials stipulated by the human resources and social security departments.

After the employer terminates or terminates the labor relationship with the employee, it shall transfer the employee's file within 15 days, hand over the Employment and Entrepreneurship Certificate and the Certificate of Termination and Termination of Labor Relationship to the employee, and inform the employee in writing to register for unemployment and enjoy unemployment insurance benefits and other related matters as required.