Vietnam tax compliance calendar for foreign-invested companies: every recurring deadline in one year

For a foreign-invested company with a calendar financial year, Vietnam's tax year runs on three rhythms. Monthly or quarterly: VAT and personal income tax withholding returns, due by the 20th of the following month for monthly filers or the last day of the first month of the following quarter for quarterly filers. Quarterly: provisional corporate income tax payments. Annually: CIT and PIT finalisation by the last day of the third month after the year end — 31 March — together with the financial statements. Tax is generally payable by the same date as the return. These deadlines come from the Law on Tax Administration (Law 38/2019/QH14).

That summary fits on a sticky note. The work is in the details: which returns your company actually files, which units file separately, who prepares and who signs, and what has changed recently. This guide sets out the full cycle, then the points where calendars most often fail. Before relying on any date, check whether the new implementing documents issued in mid-2026 — Decree 252/2026/NĐ-CP and Circular 89/2026/TT-BTC, both guiding the Law on Tax Administration — have changed anything relevant to your company.

The three rhythms at a glance

Whether a company files monthly or quarterly is not a free choice; it depends on criteria in the rules, mainly revenue. A new company often starts on one rhythm and moves to the other. Confirm yours in the company's e-tax account rather than from memory.

Month by month for a calendar-year company

A practical way to read the calendar is by the month in which the work lands:

• January. December monthly returns by 20 January. Fourth-quarter quarterly returns by 31 January. Year-end close begins: inventory counts, accruals, intercompany confirmations. Tết often falls in late January or February and eats working days.
• February. January monthly returns. Audit fieldwork usually starts. Draft the CIT add-back schedule and the employer PIT finalisation.
• March. February monthly returns by 20 March. CIT finalisation, employer PIT finalisation, audited financial statements and related-party information by 31 March. Final CIT and PIT balances payable by the same date.
• April. March monthly returns and first-quarter quarterly returns by 30 April. Employees who finalise PIT themselves file by 30 April. Public holidays at the end of April often shift the effective deadline.
• May to December. The monthly or quarterly rhythm continues, with provisional CIT at each quarter. Mid-year is the time to re-forecast CIT and top up provisional payments rather than discovering a shortfall at finalisation.

One date has disappeared: the business licence fee was abolished from 1 January 2026 under Resolution 198/2025/QH15, so there is no longer a licence fee declaration or payment at the start of the year. Earlier years that were due and unpaid remain payable.

Provisional CIT: the payment that causes the most surprises

Corporate income tax is not filed quarterly, but it is paid quarterly on a provisional basis. At finalisation, the total of the four provisional payments is compared with the final liability. If provisional payments fall short by more than the permitted margin, late-payment interest runs on the shortfall, counted from a provisional-payment deadline rather than from 31 March. Check the current margin, and the date from which interest is counted, in the implementing rules rather than relying on older summaries.

What works in practice:

1. Forecast full-year taxable income each quarter, not only accounting profit. Add-backs, such as non-deductible expenses and interest above the related-party cap, can move taxable income a long way from profit.
2. Recalculate the rate that applies. Under Law 67/2025/QH15 the standard rate is 20%, with 15% and 17% for companies whose total annual revenue does not exceed VND 3 billion or VND 50 billion respectively. A company near a threshold should check before each payment.
3. Pay the fourth-quarter instalment on the best estimate available, because it is the last chance to close the gap before interest starts to matter.

The annual pack due by 31 March

For a calendar-year FIE, 31 March is the busiest date of the year. The pack usually contains:

• CIT finalisation return with its appendices, including incentive calculations where the company has a qualifying project.
• Related-party information filed with the CIT finalisation, and transfer pricing documentation prepared and kept ready. Tax administration for related-party transactions is now governed by Decree 255/2026/NĐ-CP, in force from 1 July 2026.
• Audited financial statements. Foreign-invested enterprises are required to have annual financial statements audited, and the statements accompany the CIT finalisation.
• Employer PIT finalisation, covering employees for whom the company finalises, including those who authorised it to do so.

The pack is due on one day, but the work behind it runs for three months. Treat 31 March as a delivery date, with internal milestones in January and February: draft trial balance, draft add-back schedule, auditor's draft, draft PIT finalisation, sign-off.

Who owns each step

A calendar without owners is a list of hopes. In most foreign-invested companies the split looks like this:

Two rules keep this working: every step has a named backup for leave and Tết, and the person who submits a return is not the only one who can see whether it was accepted.

Deadlines that are not on a fixed rhythm

Some obligations are triggered by events rather than dates:

• Foreign contractor tax on payments to overseas suppliers, declared for each payment or monthly depending on how the company is registered to declare it. Missing it is common when a regional office pays an invoice without telling Vietnam.
• Changes in tax registration — address, legal representative, business lines — which must be notified within the period set by the rules. Circular 90/2026/TT-BTC is the current circular on tax registration.
• Restructuring — mergers, conversions, closure of a branch — each with its own finalisation deadline counted from the event.
• Refund claims, which have their own timetable once filed.

These belong on the calendar as rules ("within X days of an event"), with a named person responsible for noticing the event. Most missed event-driven deadlines were missed because nobody in the finance team heard about the event in time.

Late payment interest and what it costs to slip

Tax paid after its deadline attracts late-payment interest, calculated per day on the amount paid late. The rate has long been 0.03% per day; check the rate in force before calculating. Interest is separate from any administrative penalty for late filing, which depends on the circumstances and is set in the penalty regulations.

Two practical points. First, interest runs from the payment deadline, which is generally the same as the filing deadline; filing on time but paying late still costs interest. Second, interest is not deductible for CIT purposes in the ordinary course, so a slipped payment costs more than its face value suggests. The cheapest control is a payment step built into the same checklist as the filing step, with the payment confirmed in the e-tax account before the item is closed.

Where to check your own calendar

• Your company's e-tax account — which returns the system expects from you, filing status, payments recorded and any amounts treated as outstanding.
• The mobile tax app — a read-only view of much of the same, useful for managers who need to see status without logging in to the full account.
• The taxpayer information lookup — your managing tax office. Since 1 July 2025 the tax administration works in three tiers: the central Tax Department, provincial and city tax offices, and grassroots tax offices.
• Your adviser or tax agent — confirmation of how the 2026 implementing documents affect your specific deadlines.

For a Vietnamese-language calendar organised by filing type, see ThueChuan.com.