Vietnam tax residency for foreigners: do you become a tax resident after 183 days and need to pay tax?

The main threshold mentioned is a cumulative stay in Vietnam of more than 183 days; the discussion treats this as the point at which a person may be considered a Vietnamese tax resident.

For travelers on tourist visas, the discussion recommends checking immigration status first: repeated visa runs do not by themselves settle tax residency, while an overstay is a separate issue.

If your tax status changes, compare the rules in your former country of residence separately. The discussion cites 13% and a possible 30% rate as an example, but the actual calculation depends on the country and income type.