Quick answer: Tax equalization is not a tax regime created by law — it is an internal corporate policy ensuring that an expert assigned abroad bears no greater (or smaller) tax burden than at home. For Vietnamese tax purposes, every amount the company pays to “top up” the expert’s tax — whether called equalization, protection or gross-up — is taxable employment income of that expert, because Article 3 of the Law on Personal Income Tax 109/2025/QH15 classifies all monetary or non-monetary benefits in any form as employment income. A poorly designed policy does not breach tax law, but it breeds internal disputes and miscomputed withholding.
Applicable legal bases
The framework below is in force as of 20 October 2026 and directly governs this article:
- Law on Personal Income Tax 109/2025/QH15 (effective 01/07/2026; provisions on employment income of resident individuals apply from tax year 2026; replaces Law 04/2007/QH12) — Article 3 (taxable income includes salary, wages, bonuses and monetary or non-monetary benefits in any form).
- Decree 253/2026/ND-CP (effective 01/07/2026) — guidance on withholding on employment income paid by organizations.
- Law on Tax Administration 108/2025/QH15 (effective 01/07/2026, replacing Law 38/2019/QH14) — withholding, substitute filing and payment obligations.
- Labor Code 2019 — contents of employment contracts and salary and allowance agreements.
In-depth analysis
The problem tax equalization solves is highly practical: a German expert facing a 42% marginal rate at home is assigned to Vietnam — with no policy, they might face a much lower effective rate in Vietnam and pocket a windfall, or conversely an expert from a low-tax country might face higher tax in Vietnam. Both outcomes breed resentment and distort global mobility policy. Tax equalization sets the principle: the expert bears only a hypothetical tax as if at home — the company absorbs the difference when actual tax exceeds the hypothetical (or claws it back when actual tax is lower).
The key Vietnamese tax point: the “top-up” the company pays does not reduce the expert’s taxable income — it increases it. Example: an expert earns gross VND 100 million/month, actual Vietnamese tax is 20 million, the company’s hypothetical tax is 25 million — the company tops up 5 million. That 5 million is the expert’s employment income, must be added to taxable income (making 105 million) and the tax recomputed. Many C&B teams forget this “loop” and under-withhold — it is the gross-up problem all over again and must be fully converted.
Three policy design models
Model 1 — Full tax equalization: the company computes a hypothetical tax (based on home-country income and brackets) and deducts it from the expert’s pay; at year-end it finalizes actual tax in Vietnam (and at home if any liability remains) and settles the difference. The expert “feels” no tax difference between countries. Suited to long-term assignments and senior management.
Model 2 — Tax protection: lighter — the company only tops up when actual tax exceeds the hypothetical; when actual tax is lower, the expert keeps the difference (no claw-back). Simpler with fewer disputes, but costlier for the company on assignments to low-tax countries.
Model 3 — No policy (net-to-net): a fixed net salary with the company bearing all tax — essentially the net-to-gross conversion exercise. Simplest to administer but most expensive, as the company bears all rate-change risk.
Whichever model is chosen, the Vietnamese tax principle is unchanged: every dong the company spends on the expert’s tax comes back as the expert’s taxable income. The policy only changes who ultimately bears the economic cost, not how the tax is computed.
Indispensable contract clauses
Most equalization disputes stem from vaguely drafted assignment agreements. Four contents are mandatory: (1) how the hypothetical tax is computed (which country’s schedule, whether family deductions count, calendar vs fiscal year); (2) coverage scope — PIT only, or also social insurance, contractor tax and fees; (3) timing of settling differences (annually or at assignment end) and who bears interest/penalties if finalization is late due to whose fault; (4) a clause for mid-assignment tax law changes (e.g., Vietnam changes its brackets) — who absorbs the resulting gap.
The agreement must also state the expert’s cooperation duties: providing home-country tax returns, authorizing the company to deal with tax authorities, and refunding to the company any tax refunds the expert receives directly from the authority (under full equalization, refunds belong to the company).
Common risks and how to prevent them
- Assuming the top-up reduces taxable income: the opposite — it increases taxable income and the gross-up loop must be computed.
- Leaving hypothetical tax undefined in the contract: endless disputes at settlement — write the formula down from the start.
- Forgetting refunds the expert receives directly: under equalization, refunds belong to the company — include a repayment clause.
- Applying a global policy without Vietnam adjustments: Vietnam’s brackets, deductions and finalization procedures differ from home — the policy needs a Vietnam-specific appendix.
Frequently asked questions
1. Is tax equalization a tax exemption scheme?
No. It is an internal group policy; Vietnamese tax law neither provides for it nor recognizes any relief from it. Every tax top-up the company pays is the expert’s taxable income.
2. If the company tops up VND 5 million of tax for the expert, is the 5 million taxable?
Yes. The top-up is the expert’s employment income under Article 3 of Law 109/2025, must be added to taxable income and the tax recomputed (the gross-up loop).
3. What is the difference between tax equalization and tax protection?
Equalization: the expert bears exactly the hypothetical tax — the company tops up when actual tax is higher and claws back when it is lower. Protection: the company only tops up when actual tax is higher; when lower, the expert keeps the difference.
4. How are tax refunds the expert receives directly handled?
Under full equalization, refunds belong to the company since it bore the actual tax cost. The contract must oblige the expert to repay them to the company.
Key takeaway for investors
Tax equalization is an HR tool, not a tax tool — it does not reduce a single dong of tax payable in Vietnam; it only decides who ultimately bears the tax cost. Design it right: define the hypothetical tax clearly, gross-up every top-up payment, and write all four mandatory contents into the assignment agreement.
This article has been quality-reviewed by the FLAW AI Legal Council This content is legal reference only and does not replace counsel for a specific case.