Quarterly provisional CIT in Vietnam: estimating payments so the year-end finalisation brings no surprise

Corporate income tax (CIT) in Vietnam is paid during the year in quarterly provisional payments and settled in the annual finalisation. The company decides how much to pay each quarter based on its own estimate of the year's taxable income. If the total paid during the year falls too far below the final liability, late-payment interest runs on the shortfall; if it is too high, the company carries an overpayment it has to offset or reclaim.

For a foreign-invested enterprise (FIE), getting the quarterly figure right is mostly a forecasting and communication exercise, not a technical one. The difficulties are practical: management accounts that ignore tax adjustments, group forecasts that change late in the year, incentives that apply to one project but not another, and — from the 2025 tax year — a choice between the 15%, 17% and 20% rates for companies near the revenue thresholds. This guide sets out a method that keeps the year-end gap small.

How the provisional system works

The procedure is set by the Law on Tax Administration (Law 38/2019/QH14) and its implementing documents — from 1 July 2026, Decree 252/2026/NĐ-CP and Circular 89/2026/TT-BTC. The outline has been stable for several years:

• For most companies there is no quarterly CIT return. The company pays a provisional amount for each quarter within the first month after the quarter ends, by the date the law sets.
• At year end, the company files the annual finalisation by the last day of the third month after the financial year ends and pays the balance by the same date.
• If the four provisional payments together fall short of the final liability by more than a tolerance set in the rules, late-payment interest is charged on the part of the shortfall above the tolerance, counted from the deadline of the fourth quarterly payment. Check the current tolerance and the counting rule in the text in force.
• If the provisional payments exceed the final liability, the overpayment can generally be offset against later liabilities or refunded.

Late-payment interest has long been calculated at 0.03% per day; check the rate currently applicable.

Step 1: start from a tax forecast, not an accounting forecast

Most provisional payment errors start with a finance team taking year-to-date profit before tax, multiplying it by 20% and paying the result. That ignores everything in the CIT adjustment schedule. A better starting point is a short tax forecast built on last year's finalisation:

1. Forecast profit before tax for the full year, not just year to date.
2. Add the recurring add-backs from last year's schedule, adjusted for known changes — for example, excess related-party interest if the parent loan is still outstanding.
3. Deduct recurring non-taxable income, such as dividends from Vietnamese investees.
4. Offset losses carried forward that are still available under the law's conditions.
5. Split incentivised and ordinary income if a project incentive applies, and apply the right rate to each part.
6. Divide by quarter in line with the business's seasonality, then pay each quarter's share, adjusting as the forecast changes.

The forecast does not need to be perfect. It needs to be reasoned, dated and updated, so that the company can show why it paid what it paid.

Step 2: settle the rate early

Under Law 67/2025/QH15, the CIT rate depends on the company's total annual revenue:

Most FIEs are well above VND 50 billion and simply use 20%. For a smaller or newly established company, the rate is not known for certain until the year's revenue is known, but the provisional payments have to be made before then. Two practical rules help:

• Use the rate that the year's forecast revenue, measured as defined in the guidance, points to — not last year's rate by default.
• If revenue is forecast close to a threshold, pay provisionally at the higher rate. Overpaying slightly costs little; underpaying across a threshold creates a shortfall that may exceed the tolerance.

If you want to compare the three rates on your own figures, the calculators on our sister site ThueSuat.com (in Vietnamese) show the effect quickly.

Step 3: revisit the estimate every quarter

Treat the provisional payment as a rolling estimate rather than a fixed instalment:

• Q1 and Q2: pay on the annual forecast. Early in the year the main risk is under-estimating a strong year.
• Q3: refresh the forecast with half-year actuals, the group's updated outlook and any new transactions — a large asset sale, a new intercompany charge, a change in an incentive.
• Q4: this is the true-up. The fourth payment should bring the cumulative total close to the expected final liability, because the tolerance is tested on the four payments together.

Hypothetical example. Suppose an FIE at 20% forecasts taxable income of VND 40 billion for the year and pays VND 2 billion in each of the first three quarters. In October, updated figures point to VND 52 billion, a liability of VND 10.4 billion. The company pays VND 4.4 billion for Q4, bringing the total to VND 10.4 billion. If the final figure turns out to be VND 11 billion, the shortfall of VND 0.6 billion is settled at finalisation; whether any interest arises depends on whether the shortfall exceeds the tolerance in the rules.

Special situations

• A newly established SME. Resolution 198/2025/QH15 provides a three-year CIT exemption for newly established small and medium-sized enterprises that meet the conditions. If the company qualifies, its provisional payments reflect the exemption; if it is not certain that it qualifies, it is safer to pay and reclaim than to assume the exemption and face a shortfall.
• A first year shorter than twelve months. The revenue test for the 15% and 17% rates and the forecast itself both need care. Read how the guidance treats a short first year before choosing the rate.
• Production units in other provinces. Where the rules require CIT to be allocated among the provinces in which dependent production units are located, the provisional payments follow the same allocation. Check whether the rule applies to your structure; getting it wrong leaves one province overpaid and another short.
• A large one-off transaction. The sale of a building, land use rights or a subsidiary can change the year's liability in a single quarter. Some transfers have their own declaration rules; for the rest, raise the next provisional payment rather than waiting for finalisation.
• A change of financial year. The transition period is a tax period of its own. Agree the provisional schedule for it with your adviser before the change takes effect.

Common reasons for a year-end gap

• Adjustments forgotten in the forecast — especially non-deductible intercompany charges, fines, or cash payments that lose deductibility.
• One-off gains — disposal of land use rights or equipment, insurance proceeds, debt forgiveness by a group company — recorded late in the year.
• Incentive errors — income from an expansion or a new product line assumed to be incentivised when it is not.
• Loss carry-forward assumptions — offsetting a loss that has expired or that does not qualify.
• Audit adjustments made after the fourth payment, such as additional provisions or revenue cut-off corrections.

Each of these is visible before the fourth quarter if someone looks for it. A 30-minute tax review of the Q3 forecast, with the previous year's adjustment schedule on the table, catches most of them.

Controls that keep provisional payments on track

1. Put the payment dates in the compliance calendar with the name of the person responsible.
2. Document each estimate in a one-page note: forecast, adjustments, rate, amount paid.
3. Keep the group informed. Parent companies often forecast Vietnamese tax from consolidated profit; share your tax forecast so that group numbers and local payments align.
4. Check the e-tax account after each payment to confirm it was credited to CIT for the right period.
5. Reconcile at finalisation the four payments against the final liability, and record the reasons for any gap.

Your e-tax account shows each provisional payment and how it was credited; the taxpayer information lookup confirms your managing office before you contact it about a misallocated payment.