Although a large number of authorities can issue legal instruments in Vietnam, the Law on Legal Instruments 2008 contains only a few rules of interpretation as follows:

• A legal instrument is applicable to events or actions, which occur when the legal instrument is effective; 
• In case two legal instruments are “different” on the same issue, then the legal instrument issued by a higher issuing authority will prevail; and
• In case two legal instruments issued by the same authority are “different” on the same issue then the more recent legal instrument will prevail. 

There is serious deficiency in how a legal instrument should be interpreted in Vietnam. For example, it is difficult to determine whether a “difference” exists between two legal instruments. For example, the Labour Code of the National Assembly provides that an employee with an indefinite employment contract must give a 45 “days” prior notice when he/she resigns. However, Circular 21 of the Ministry of Labour, War, Invalids and Social Affairs (MOLISA) requires the employee to give 45 “business days” prior notice when he/she resigns. One can challenge the validity of Circular 21 by arguing that there is a difference between the Labour Code 1994 issued by the National Assembly and Circular 21 issued by the MOLISA and that the National Assembly is a higher issuing authority. On the other hand, as the MOLISA is empowered to issue implementing regulation and clarify the law of the National Assembly, one can counter-argue that in Circular 21 the MOLISA only “further clarifies” what “days” in the Labour Code means in the relevant context.

In addition, Vietnamese law is not clear when a law or decree is issued to repeal an existing law or decree then whether or not the implementing legal instruments of the repealed law or decree will continue to be effective after the new law or decree is issued. Under Article 78.4 of the Law on Legal Instruments 1996, implementing regulations of a repealed legal instrument will also be repealed unless otherwise permitted. Unfortunately, the Law on Legal Instruments 2008 does not contain the same provision.

In practice, Government authorities still tend to apply implementing legal instruments of a repealed legal instrument until a new implementing legal instrument on the same issue is issued. However, there is nothing at law to prevent a Government authority from choosing not to apply implementing legal instruments of a repealed legal instrument on the basis that such implementing legal instruments is “different” from the new law. 

The risk of adverse or unpredictable interpretation is high when there is a significant time lag between the issuance of new law and the issuance of its implementing legal instruments. For example, Decree 160/2006 on foreign exchange was issued to replace Decree 63/1998 in 2006. However, it has been nearly 6 years and the State Bank of Vietnam has not issued all necessary implementing circulars for Decree 160/2006. During this 6-year period, it is not always clear whether the circulars implementing Decree 63/1998 are still effective and if so, how they are implemented or interpreted in light of Decree 160/2006.

Finally, Vietnamese law is not clear on how to deal with the situation when there are two conflicting legal provisions issued by two different authorities who are at the same level. To address this situation, some laws contain a provision that in case there is a conflict between such laws and other “special” (đặc thù) laws then “special” laws will prevail. However, this gives rise to two other problems:

• Except in case of Enterprise Law, it is usually not clear which laws are considered as “special laws”; and
• It is not clear whether an implementing regulation of a special law which is issued by a lower authority will prevail the “general” law issued by a higher authority.