Answer:
The salary serving as the basis for payment of compulsory insurance premiums includes the salary, allowances, and other additional amounts as prescribed by labour law[1]. Pursuant to the guiding documents, allowances and other additional amounts do not include bonuses[2].
From the analysis above, the salary serving as the basis for payment of compulsory insurance premiums will exclude all bonuses. Furthermore, salary is agreed between the parties and included in the LC so it is not against the law for the Employer (as agreed with the Employee) to set a fixed salary excluding bonuses in order to pay compulsory insurance premiums required by Labour Code after the Employee reached the salary threshold limit in the salary scale.
[1]Article 89 of the Law on SI
[2]Article 6.2.3 of the Decision No. 595/QD-BHXH dated 14/04/2017