1. The issue: tax planning happens before the flight
Most PIT trouble foreign experts face in Vietnam originates from decisions (or non-decisions) made before arrival: the start date, how salary is agreed gross or net, and failing to prepare a residence certificate. Planning PIT before relocating to Vietnam lets you control all three while they can still be changed.
2. Step 1: map the first year’s residency
A resident is a person present in Vietnam for 183 days or more in a calendar year or in 12 consecutive months from the first day of presence, or having a regular place of abode in Vietnam. In practice, an expert arriving in the second half of the year may not be resident in year one but will “slide” into residency under the 12-consecutive-month rule in year two — bringing worldwide-income taxation and progressive finalization under Law 109/2025/QH15 (allowances of VND 15.5 million/month for the taxpayer and VND 6.2 million/month per dependent from the 2026 tax year). The start date is therefore a real planning variable, not mere logistics.
3. Step 2: negotiate salary and who bears the tax
Settle in the contract/secondment letter: gross or net salary; if net, the employer bears the tax and must gross it up into taxable income; under tax equalization, the retained hypothetical tax is internal, while the actual Vietnamese liability is still computed on real income. Shape the benefit package tax-efficiently within the law: rent inside the 15% cap, children’s school fees from kindergarten to high school, the annual home-leave airfare — items excluded from, or capped within, taxable income.
4. Step 3: prepare treaty documents and the residence certificate
Check whether the current residence state has a double tax treaty with Vietnam (Vietnam has signed 81) and obtain that year’s Certificate of Residence (COR) from that state’s tax authority — a COR requested late is slower and harder than one requested in-year. Prepare the treaty relief notification dossier if a short-presence exemption in Vietnam is expected, and plan foreign tax credits at finalization on both sides.
5. Step 4: set up compliance from month one
Register a personal tax code as soon as the first Vietnam income arises (forms under Circular 90/2026/TT-BTC, via the payer or self-registration); agree the withholding mechanics with the subsidiary (who withholds when pay is split); and archive all withholding certificates, income confirmation letters and foreign tax documents. One key warning: a “split payroll” structure does not make Vietnam-source income disappear — all Vietnam work must be declared in Vietnam wherever it is paid; lawful planning optimizes within the rules, it does not conceal income sources.
6. Key takeaways
Pre-relocation tax planning is four tasks: choose, and understand the residency consequences of, the start date; lock the gross/net and tax equalization mechanics into the secondment documents; prepare the COR and treaty file for the right year; and set up tax registration and document archiving from month one. Done properly, the first Vietnamese finalization season becomes paperwork, not crisis management.
7. Frequently asked questions
1. Arriving in September — am I resident in the first year?
On a calendar-year basis, presence from September to year-end is under 183 days; but the 12-consecutive-month rule from the first day of presence can make you resident in the following period, with a first tax period spanning 12 months. Model it on the expected presence calendar before signing.
2. Should salary be agreed gross or net for a Vietnam posting?
Net salary with an employer-borne tax (gross-up) mechanism stabilizes take-home pay and is standard for international assignments; in return the employer must budget the grossed-up tax correctly on the 2026 progressive scale and record it in the secondment letter.
3. How long is a COR from the residence state usable?
A COR is issued for a specific residence year and supports the treaty file for that year; request it in the year the Vietnamese income arises and keep the original with a translation for the Vietnamese tax authority.
4. Should the plan also cover the exit from Vietnam?
Yes. The pre-departure finalization duty, dependent dossiers and withholding certificates needed for home-country credits are all far easier to prepare if planned from the start rather than in the final month.
This article has been quality-reviewed by the FLAW AI Legal Council
