Social security arrears cannot be paid by the new unit.

Legal analysis: if the arrears are not paid, the new unit cannot handle employee insurance. It is the right of the employee and the obligation of the employer to establish a labor relationship, conclude a labor contract and pay social security within one month from the date of employment. If the employer does not sign a labor contract or participate in endowment insurance, it violates the provisions of the Labor Contract Law and the Social Insurance Law. Social security can be paid. As long as the employee provides the labor contract and payroll to the social security department, the social security department can require the employer and the employee to pay according to their respective proportions.

Legal basis: Measures for the Administration of Personal Rights and Interests Records of Social Insurance in People's Republic of China (PRC) Article 10 When the insured person transfers employment due to social insurance, the social insurance agency in the newly insured place shall receive and manage the personal rights and interests records of social insurance in time; The social insurance agency of the original insured place shall keep the original records for future reference after transferring the records of individual rights and interests of social insurance.