3 issues regarding work permits for foreigners working in Vietnam.

Based on Article 151 of the Labor Code, it is stipulated that:

Article 151. Conditions for foreign workers to work in Vietnam

1. Foreign workers in Vietnam are those who are foreign nationals and must meet the following conditions:
   a) Must be 18 years of age or older and have full legal capacity;
   b) Possess professional, technical, vocational, and work experience; and have sufficient health as prescribed by the Minister of Health;
   c) Not a person who is currently serving a sentence, has not had their criminal record expunged, or is being prosecuted under foreign law or Vietnamese law;
   d) Possess a work permit issued by a competent state agency of Vietnam, except as stipulated in Article 154 of this Code.
2. The term of an employment contract for foreign workers in Vietnam must not exceed the term of their work permit. When employing foreign workers in Vietnam, both parties may agree to enter into multiple fixed-term employment contracts.
3. Foreign workers in Vietnam must comply with Vietnamese labor laws and are protected by Vietnamese law, except in cases where international treaties to which the Socialist Republic of Vietnam is a party provide otherwise.

At the same time, Clause 9, Article 9 of Decree 152/2020/ND-CP stipulates as follows:

9. Application dossier for work permit in certain special cases:

a) For foreign workers who have been granted a valid work permit and wish to work for a different employer in the same position and job title as stated in the work permit, the application for a new work permit shall include: a confirmation letter from the previous employer stating that the worker is currently employed, the documents specified in clauses 1, 5, 6, 7, and 8 of this Article, and a certified copy of the previously issued work permit;

b) For foreign workers who have been granted a valid work permit and change their job position, job title, or form of work as stated in the work permit in accordance with the law, but without changing the employer, the application for a new work permit shall include the documents specified in clauses 1, 4, 5, 6, 7, and 8 of this Article and the work permit or a certified copy of the previously issued work permit.”

Therefore, according to the regulations above, you are working for two companies, which are two independent legal entities and two employers. Consequently, the second company, when employing foreign workers, must go through the procedure of applying for work permits for those workers.