I. INTRODUCTION – NOT ALL VIOLATIONS HAVE THE SAME TIME LIMIT
The 2025 Tax Administration Law clearly distinguishes:
- Tax procedure violations -> 2-year time limit
- Misdeclarations causing tax shortfall / tax evasion -> 5-year time limit
Common mistakes:
- Businesses remember “5 years” but do not distinguish the violation type.
II. LEGAL BASIS – CLASSIFYING THE TIME LIMITS
1) The 2-year time limit
Typically applies to:
- Late filing of tax returns
- Failure to submit required appendices
- Incorrect forms/templates
- Administrative/procedural mistakes
Time is counted from: The date the violation is committed
2) The 5-year time limit
Typically applies to:
- Misdeclaration leading to tax shortfall
- Misdeclaration increasing refundable tax
- Tax evasion
Time is counted from: The date the violation is committed
III. NUMERIC EXAMPLES
Case 1 – Late filing of VAT return
- Due date: 20/04/2026
- Filed on: 30/05/2026
- Administrative penalty range: 2–8 million VND (depending on severity)
- Penalty time limit -> Until 20/04/2028
After this date -> no administrative penalty.
However: If a tax shortfall is involved -> the 5-year time limit may apply.
Case 2 – Under-declared revenue
Year 2026: Under-declared revenue of 2 billion VND • CIT 20% = 400 million VND
- Penalty time limit -> Until the end of 2031
- If detected within 5 years:
- Back tax: 400 million VND
- Penalty 20%: 80 million VND
- Late payment interest: 0.03%/day
Assuming 3 years: 400,000,000 x 0.03% x 1,095 days ≈ 131 million VND
Total ≈ 611 million VND
IV. THE KEY DIFFERENCES
| Item | 2 years | 5 years |
|---|---|---|
| Procedural violations | Yes | No |
| Tax shortfall | No | Yes |
| Tax evasion | No | Yes |
| Back tax assessment | May apply | Applies |
Remember: The expiry of the penalty time limit does not mean the tax obligation disappears.
V. RISKS DURING A TAX AUDIT
An audit may:
- Review the most recent 5 years
- Request full supporting documents
- Reconcile with e-invoice data
If a business:
- Does not archive properly
- Cannot provide clear explanations
-> It is likely to be classified as high risk.
VI. HOW TO PREVENT AUDIT RISKS
1. Prepare records on a 5-year cycle
At a minimum, retain:
- Financial statements
- General ledger
- E-invoices
- Major contracts
- Acceptance/hand-over minutes
2. Run annual internal reviews
Check:
- Revenue – invoices
- Input VAT
- Expenses > 500 million VND
- Related-party transactions
3. Build an audit response process
When receiving an audit decision:
- - Assign a single point of contact
- - Prepare dossiers in advance
- - Do not provide information beyond what is requested
- - Keep clear working minutes
VII. REAL CASE – A CONSTRUCTION BUSINESS
A company with revenue of 150 billion VND/year. Audit reviews 5 years:
Findings: Under-declared 1 billion VND per year -> 5 years = 5 billion VND
- CIT: 1 billion VND
- Penalty 20%: 200 million VND
- Average late interest over 3 years ≈ 300 million VND
Total ≈ 1.5 billion VND
A small annual mistake becomes a large number when accumulated.
VIII. RISK-REDUCTION STRATEGY
- 1) Do not let errors persist beyond 1 year
- 2) File amendments early (Article 12 – 5 years)
- 3) Do not rely on “we won’t be audited” thinking
- 4) Build a culture of transparency
IX. DO-IT-NOW CHECKLIST
- - Review the last 3 years
- - Re-check high-value revenue dossiers
- - Create a 5-year time-limit tracking sheet
- - Issue an internal audit-handling procedure
- - Back up electronic records
X. CONCLUSION – THE TIME LIMIT IS A LEGAL BOUNDARY
The 2-year vs 5-year rules are not to “wait out the deadline”, but to:
- Self-check – self-correct – self-protect.
A strong business is one that:
- Is not afraid of audits
- Is not afraid of back tax
- Is not afraid of data reconciliation
Next: Part 7 – Tax audit 2026: process, powers & professional conduct?
