When is the unit required to buy social security for employees?

As long as the contract between the parties and the employer takes effect, they should participate in the five insurances of social security for workers; Employers and individuals who pay social insurance premiums according to law have the right to inquire about payment records and personal rights records, and require social insurance agencies to provide social insurance consulting and other related services. Individuals enjoy social insurance benefits according to law and have the right to supervise the payment of their own units.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.