According to Clause 3 Article 21 of Circular No. 92/2015/TT-BTC
, if a foreigner is a resident in Vietnam, when terminating the employment contract and leaving Vietnam, the foreigner has to make PIT accounting.
PIT accounting must be declared before the foreigner exits Vietnam. However, if the foreigner has not yet made PIT accounting but he/she has left Vietnam, the foreigner may authorize the income payer or other organization/individual to make PIT accounting on his/her behalf within 45 days from the date of departure.
The tax accounting period is determined from January or from the first month of arrival in Vietnam until the month when the employment contract terminates and the foreigner exits Vietnam.