From year-end close to 31 March: a working timetable for CIT finalisation, audit and PIT in Vietnam

For a foreign-invested company with a calendar financial year, the last day of the third month after year end — 31 March — is the deadline under the Law on Tax Administration (Law 38/2019/QH14) for the corporate income tax finalisation and the employer's personal income tax finalisation, and any balance of tax is payable by the same date. The audited financial statements and the related-party information travel with the CIT finalisation. Everything that feeds those documents has to be finished in roughly ten working weeks, one or two of which disappear into Tết.

The companies that make 31 March comfortably do not work harder in March. They move work into October and November, and they treat the group reporting deadline in January as a milestone rather than as the end of the job. This guide sets out a timetable that works for most mid-sized FIEs, with the tasks that slip most often and the reasons they slip.

The pack due on 31 March

Tax administration of related-party transactions is now governed by Decree 255/2026/NĐ-CP, which took effect on 1 July 2026. If your transfer pricing documentation was prepared under the previous framework, include a review against the new decree in the timetable below. Foreign-invested enterprises are required to have their annual financial statements audited.

October and November: the work that saves March

• Agree the audit plan with the auditor: interim visit dates, inventory count dates, deadline for the draft report. Auditors' calendars fill quickly for the first quarter.
• Review intercompany agreements. Every recharge, management fee, royalty and loan booked this year should have a signed agreement dated before the charges. Fix gaps now, not after the auditor asks.
• Estimate full-year taxable income and the fourth-quarter provisional CIT payment. Under Law 67/2025/QH15 the standard rate is 20%; companies with total annual revenue not exceeding VND 3 billion pay 15%, and those above VND 3 billion up to VND 50 billion pay 17%.
• Clean the balance sheet: old advances, suspense accounts, unreconciled supplier balances. Each of these becomes an audit question or a tax adjustment later.
• Start PIT housekeeping: check that dependants registered for family deduction have the right documents, and identify employees who will need to finalise themselves.

December and January: close and first filings

• Inventory count and cut-off at year end, with the auditor observing where planned. Match the last deliveries of the year to e-invoices issued: invoice timing follows the invoice rules, not the accounting cut-off, and mismatches here produce VAT questions.
• Accruals. Expenses booked without invoices at year end need proper invoices and documents to be deductible. Chase suppliers in January and track which accruals still lack invoices by the time the CIT return is prepared.
• December monthly returns by 20 January; fourth-quarter quarterly returns by 31 January for quarterly filers.
• Group reporting. Most groups need year-end numbers in January. Treat that submission as a draft for the local statutory accounts; the audit will adjust it.
• Collect PIT authorisations from employees who qualify to have the company finalise on their behalf.

Tết usually falls in late January or February. Put it on the timetable explicitly and assume the week before and the week after are half-weeks.

February: audit fieldwork and the tax computation

February is when the tax computation should be built, alongside the audit rather than after it:

1. Add-back schedule. Go line by line through expenses against the conditions for deductibility: actually incurred and business-related, supported by lawful invoices and documents, and paid by non-cash means where required. For VAT, input invoices of VND 5 million or more require non-cash payment evidence (Law 48/2024/QH15).
2. Incentives. If a project enjoys a CIT incentive, confirm income is separated correctly and the incentive conditions are still met.
3. Related parties. Prepare the related-party information from the intercompany ledger and check interest on group loans against the cap in the transfer pricing rules.
4. Payroll reconciliation. Reconcile payroll expense in the accounts with PIT withholding returns filed during the year. Differences here are among the most common findings in tax audits of FIEs.
5. Family deductions from 2026. For the 2026 tax year onward, the personal deduction is VND 15.5 million per month and each dependant VND 6.2 million per month (Resolution 110/2025/UBTVQH15). Make sure payroll applied the right amounts through the year.

Group reporting and the local statutory accounts

Most of the friction in a Vietnamese year end comes from running two sets of numbers on two timetables. The group wants IFRS or its own reporting framework in January; Vietnam needs statutory financial statements prepared under Vietnamese accounting rules, audited, by 31 March. The two are built from the same ledger but they are not the same document, and the tax return is built from the Vietnamese one.

Three habits keep the gap manageable:

• Keep a standing reconciliation between the group reporting package and the local trial balance, updated each quarter rather than rebuilt in February. Typical items are provisions, leases, revenue timing and foreign exchange.
• Agree late adjustments once. A group adjustment posted in February after local numbers have gone to the auditor creates a second round of audit work. Set a cut-off date for group adjustments that affect the local accounts.
• Explain the difference in Vietnamese and English. The legal representative, often an expatriate, signs Vietnamese financial statements that differ from the figures reported to headquarters. A one-page bilingual bridge explaining why protects everyone.

Where the group reports a different profit from the Vietnamese statements, remember that the tax authority sees only the Vietnamese statements and the return. The bridge is for internal comfort; the tax position rests on the local numbers.

March: sign-off, filing and payment

• First half of March. Auditor's draft report and adjustments agreed. Tax computation updated for audit adjustments. Employer PIT finalisation finalised.
• By 20 March. February monthly returns filed as usual; the year-end work does not pause the monthly rhythm.
• Third week. Legal representative and chief accountant sign the financial statements; management representation letter signed; CIT return and appendices reviewed by the tax adviser.
• By 31 March. CIT finalisation, related-party information, audited financial statements and employer PIT finalisation submitted; balances paid; payment confirmed in the e-tax account.

If 31 March falls on a weekend or public holiday, the deadline moves to the next working day. Do not plan to use that extra day; it is the buffer for a portal that runs slowly on the last day.

The tasks that slip, and why

After 31 March

The finalisation is not quite the end. Employees who finalise PIT themselves have until the last day of the fourth month — 30 April, and they will ask for income certificates from the company. First-quarter quarterly returns and March monthly returns are due by 30 April as well, just as the late-April holidays arrive. And any late-payment interest on a CIT shortfall — long calculated at 0.03% per day, but check the rate in force — keeps running until the balance is paid.

Keep the working papers together: trial balance, add-back schedule, related-party analysis, payroll reconciliation and original e-invoice files. Accounting documents used directly for bookkeeping and preparing financial statements must be kept for at least 10 years under the Law on Accounting. For a Vietnamese-language guide to keeping these records, see ThueChuan.com.