Conditions for foreign citizens who apply for Vietnamese nationality to be granted Vietnamese nationality are specified in Clause 1, Article 19 of the 2008 Vietnamese Nationality Law as follows:

“Conditions for naturalization in Vietnam

1. Foreign citizens and stateless people permanently residing in Vietnam who apply for Vietnamese nationality can be granted Vietnamese nationality if they meet the following conditions:

a) Have full civil act capacity according to Vietnamese law;

b) Comply with the Constitution and laws of Vietnam; Respect the traditions, customs and practices of the Vietnamese people;

c) Know enough Vietnamese to integrate into the Vietnamese community;

d) Have permanently resided in Vietnam for 5 years or more by the time of applying for Vietnamese nationality;

d) Able to ensure life in Vietnam.

…” 

Accordingly, foreign citizens who apply for Vietnamese nationality can be granted Vietnamese nationality if they fully meet the conditions specified in Clause 1, Article 19 above. It must be able to ensure life in Vietnam.

According to the instructions in Clause 3, Article 7 of Decree 16/2020/ND-CP, the ability to ensure a life in Vietnam of a person applying for Vietnamese nationality is proven by that person's assets and legal sources of income. or the guarantee of an organization or individual in Vietnam.

Therefore, to gain Vietnamese citizenship, a foreign citizen must prove his or her assets, prove his/her legal income, or have a guarantee from an organization or individual in Vietnam.

However, according to Clause 2, Article 19 of the 2008 Vietnamese Nationality Law, foreign citizens can be naturalized in Vietnam without proving income when they fall into one of the following cases:

- Being the wife, husband, biological father, biological mother or biological child of a Vietnamese citizen.

- Have special contributions to the cause of building and protecting the Vietnamese Fatherland.

- Beneficial for the State of the Socialist Republic of Vietnam.