On July 20th ,2020, The General Department of Taxation issued Official Letter No. 2881/TCT-DNNCN provide guidance on determining residents in the tax year as follows:
If individuals are foreigners who enter Vietnam and meet one of the following conditions: He/she has been present in Vietnam for at least 183 days in a calendar year or for 12 consecutive months from the date of his/her arrival in Vietnam, or He/she has a regular residence as prescribed by the law of residence or has rented a house/apartment/room for a stay under the lease contract(s) in Vietnam that have/has the total term of at least 183 days in the tax year, they will be determined as residents.
For individual that has a regular house in Vietnam but actually is present in Vietnam for less than 183 days in the tax year, if they can not prove to be a resident of any country, that individual will be a resident of Vietnam.