Setting up the tax calendar for a new Vietnamese subsidiary: first-year deadlines, financial year choice and holidays

A new Vietnamese subsidiary should have its tax calendar built before its first sale, not after its first return is due. In the first weeks that means setting up the company's e-tax account, digital signature and e-invoice registration; then confirming which filing period applies to a newly started business; then fixing the accounting year, because the corporate income tax finalisation is due on the last day of the third month after the financial year ends under the Law on Tax Administration (Law 38/2019/QH14). Personal income tax follows the calendar year whatever the company chooses.

Groups usually plan incorporation carefully and then hand the new entity to a shared service team with a copy of another subsidiary's calendar. That works until the first difference — a different filing period, a different year end, a first accounting period of odd length — lands on a Tết week. This guide sets out the decisions and dates for year one, in the order they come up.

Before the first sale: the set-up steps that carry deadlines later

For companies, the enterprise code issued at registration is also the tax code, so the company exists for tax purposes from registration. Before it invoices anything, it should have:

1. A digital signature and e-tax account, so returns can be filed and payments tracked in the company's own name.
2. A bank account in the company's name, used for tax payments and for receiving customer payments. Purchases of VND 5 million or more need non-cash payment evidence for input VAT credit (Law 48/2024/QH15), so cash purchases from day one are a false economy.
3. E-invoice registration accepted by the tax authority through an e-invoice service provider. A company may only issue e-invoices once its registration is accepted.
4. Registered tax details checked — address, legal representative, managing tax office — in the taxpayer information lookup. Circular 90/2026/TT-BTC is the current circular on tax registration.
5. Named owners for each tax task, with backups.

One set-up cost has disappeared: the business licence fee was abolished from 1 January 2026 under Resolution 198/2025/QH15, so a company formed in 2026 has no licence fee declaration to make.

The first filing period

Under the rules that have applied since 2020 (Decree 126/2020/NĐ-CP), a newly started business has been able to file VAT and PIT withholding quarterly for an initial period, before its revenue history decides between monthly and quarterly filing. Implementing rules were reissued in 2026 — Decree 252/2026/NĐ-CP guides the Law on Tax Administration from 1 July 2026 — so confirm how the current rules treat a new business, particularly one that starts mid-year.

The deadlines themselves come from the law: monthly returns by the 20th of the following month; quarterly returns by the last day of the first month of the following quarter. A company that starts operating in November and files quarterly has its first VAT return due by 31 January — a date that often falls close to Tết.

A new company with no sales in its first period still files. Nil returns are part of the calendar; missing them is one of the commonest early compliance failures, and it makes the company look inactive to the tax authority's systems.

Choosing the financial year

Under the Law on Accounting a company's accounting year is twelve months, starting on 1 January or on the first day of another quarter. Most FIEs choose the calendar year, but a group with a different year end — 31 March or 30 June, for example — often aligns the Vietnamese subsidiary with it. The first accounting period after incorporation may be shorter or somewhat longer than twelve months, within the limit the Law on Accounting allows.

The table shows the practical cost of a non-calendar year: two year ends to run, one for CIT and statutory accounts, one for PIT. Some groups accept that to keep one global close; others prefer the calendar year in Vietnam and a reconciliation at group level. Decide before the first accounting period ends; changing later is possible but creates a transitional period to manage.

Corporate income tax in the first year

• Provisional payments. CIT is paid provisionally each quarter even in the first year. A company in start-up losses may have nothing to pay, but it should still forecast, because a profitable second half can create a shortfall at finalisation.
• Rate. 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%. Measure revenue as the implementing guidance defines it, especially for a short first period.
• SME exemption. Resolution 198/2025/QH15 provides a three-year CIT exemption for newly established small and medium-sized enterprises that meet the conditions. Check the SME criteria and the other conditions before assuming it applies, and keep the evidence.
• Project incentives. Where the investment project qualifies for a CIT incentive, the timing of the incentive period and the separation of incentivised income matter from the first year. Confirm the position in writing with your adviser.

Group charges and payments abroad from day one

New subsidiaries are often funded and served by the group from the first week: the parent seconds staff, pays set-up costs, licenses software and charges for services. Each of these creates tax dates that are easy to miss because nobody in Vietnam initiated the transaction.

• Foreign contractor tax. Payments by the Vietnamese company to overseas suppliers, including group companies, can carry foreign contractor tax, declared for each payment or monthly depending on how the company registers. The deadline follows the payment, so the Vietnamese team must know when the payment is made.
• Intercompany agreements. Recharges and service fees need signed agreements dated before the charges, and evidence that the services were received. Without them the expense is hard to deduct, and the tax on it cannot be recovered later.
• Costs paid by the parent before incorporation. Pre-incorporation expenses recharged to the new company need documents that show what they were and who benefited. Collect them in the first month, while people remember.
• Seconded staff. Expatriates working for the subsidiary from the start bring personal income tax registration and withholding into the first payroll, even if they are still paid from abroad.

Holidays and deadlines that move

When a tax deadline falls on a weekend or public holiday, it moves to the next working day. Vietnam's public holidays include the Lunar New Year (Tết), the Hung Kings Commemoration Day, Reunification Day on 30 April, International Labour Day on 1 May and National Day on 2 September, with dates and bridging days announced each year. Three periods cause most trouble:

• Tết, usually in late January or February. It lands close to the 20 January and 20 February monthly deadlines and the 31 January quarterly deadline, in the middle of year-end close. Offices, banks and suppliers slow down for longer than the official holiday.
• 30 April and 1 May, right on the quarterly deadline for the first quarter and the deadline for individuals' own PIT finalisation.
• 2 September, close to the 20 September monthly deadline in some years.

The rule protects you from a deadline that falls on a holiday. It does not protect you from a bank that closes early the day before, or from a reviewer who is on leave. Plan to file and pay before the holiday, and treat the shifted deadline as a buffer.

Building the calendar: a template for year one

1. List every obligation the company has: VAT, PIT withholding, provisional CIT, CIT finalisation, employer PIT finalisation, foreign contractor tax, financial statements, related-party information.
2. Attach the rule to each: "20th of the following month", "last day of the third month after year end", "each payment to an overseas supplier".
3. Generate the dates for the first eighteen months, applying the holiday shifts announced for the year.
4. Add internal milestones a few working days before each deadline: preparation, review, payment released.
5. Name the owner and backup for each line, and the person who confirms acceptance in the e-tax account.
6. Review quarterly in year one, because the filing period, rate and incentive position may all change as the business grows.

For a Vietnamese-language checklist aimed at newly established companies, see ThueChuan.com.