Who pays for social security when an employee leaves on the 20th

Employee 20 left social security is usually paid by the employer. If the employer pays before the 20th, the employee's social security for the month has been paid by the unit; if the employer pays after the 20th, the social security of the unit's employees, the employee's social security unit for the month will not be paid. The laborer shall, in accordance with the agreement of both parties, handle the handover of work. Where the employer is required to pay economic compensation to the worker in accordance with the relevant provisions of this Law, it shall do so at the time of handing over the work. The employer shall keep the text of the canceled or terminated labor contract for at least two years for reference.