Tax compliance in Vietnam is a calendar sport: the rules are knowable, the deadlines are fixed, and almost every penalty we see was avoidable with a working checklist. Here is the corporate income tax compliance rhythm every foreign-invested company should run.
The annual tax compliance calendar
Quarterly
Provisional CIT payments fall due after each quarter – and the law penalises aggregate underpayment against the annual result, so quarterly estimates need real forecasting, not habit. VAT and PIT filings run monthly or quarterly by taxpayer size.
Year-end
The annual CIT finalisation – due ninety days after fiscal year-end – is the main tax compliance event: audited statements, the finalisation return, related-party disclosures, and the transfer pricing documentation that must already exist when you file.
Continuous
E-invoice discipline on every transaction, contemporaneous documentation for deductible expenses, and the licence-fee and reporting obligations that attach to the investment certificate.
Where tax compliance actually fails
Deductibility documentation is the biggest audit battleground: expenses real but papered badly – missing contracts, invoices that fail e-invoice rules, payments over the cash threshold without bank transfer. Related-party pricing is second. Incentive conditions are third – preferential rates claimed without the separate books to prove entitlement, the trap our incentives guide details. The new rates and rules under the CIT Law 2025 make a fresh tax compliance review worthwhile even for veterans.
Building a tax compliance system that survives audit
Three components: a compliance calendar with owners and reminders; a documentation standard – every deduction traceable to contract, invoice and payment within minutes; and an annual health check before the finalisation, when errors are still corrections rather than findings. Voluntary amendment before an audit notice caps exposure dramatically – the single most valuable tax compliance habit a CFO can institutionalise.
Corporate income tax compliance: frequently asked questions
What are the penalty stakes?
Late payment interest accrues daily; understatement penalties add 20% of the shortfall; evasion findings multiply from there and can turn criminal. Timely, documented tax compliance is cheap against any of these.
How far back can audits reach?
Assessment periods stretch years back, and transfer pricing files must be produced on tight deadlines when requested – retrospective reconstruction rarely convinces anyone.
What does outsourced tax compliance support cost?
Our tax advisory team runs retainers sized to filing volume – reviewing before submission, answering the weekly questions, and standing in front of auditors when they come. Official deadlines are published by the Ministry of Finance.
Penalties: what non-filing actually costs
The arithmetic is unforgiving. Late payment accrues interest at 0.03 percent per day – roughly eleven percent a year – on top of the shortfall. Under-declaration discovered on audit adds an administrative penalty of twenty percent of the underpaid amount; conduct treated as evasion escalates to one to three times the tax. Late filing of returns carries its own fixed fines, and a pattern of missed deadlines moves the company up the audit-selection ranking. The cheapest correction is always the voluntary one: amending a return before an audit notice arrives caps the exposure at interest, without the twenty percent surcharge.
What draws an audit – and what an inspector reads first
Selection is risk-scored. Persistent losses beside growing revenue, related-party charges without contemporaneous files, refund claims, big swings in effective tax rate, and heavy intercompany service fees are the classic flags. Once on site, inspectors start with deductibility: does every material expense trace to a proper VAT invoice, a contract, and bank-transfer evidence? Cash payments above the statutory threshold are non-deductible regardless of authenticity, and missing e-invoice linkage is the fastest disallowance in the book. A company that reconciles its invoice ledger to its general ledger quarterly walks into an audit with the argument already won.
Frequently asked questions
Do provisional quarterly payments have a floor?
Yes – total provisional payments for the year must reach at least eighty percent of the final annual liability, or late-payment interest applies to the shortfall from the fourth-quarter deadline. Groups with seasonal profits should model this in October, not discover it at finalisation.
Can losses be carried forward?
Losses carry forward continuously for a maximum of five years, against future taxable income, with no carry-back. The five-year clock and the documentation of each loss year both survive ownership changes, which is one reason buyers diligence the tax file so closely.
When do incentives interact with the filing calendar?
Preferential rates and exemption holidays are claimed through the annual finalisation, supported by the incentive conditions – sector, location, capital disbursement – being demonstrably met that year. Claiming an incentive the project no longer qualifies for is treated as under-declaration, so the eligibility check belongs in the year-end close, every year.
This article is provided for general information only and does not constitute legal advice for any specific case. Regulations may change – please consult a qualified professional before acting. Should further analysis be required, please contact one of our lawyers below.
