GDT tax returns — full filing calendar
GDT filing calendar — monthly returns by the 20th, annual TOI return + patent tax on 31 March, e-filing, late penalties 10/25/40% + interest.
- Duration
- Monthly (20th of the following month) + annual (31 March)
- Difficulty
- Moderate
- Reading
- 8 min
In 3 bullets
- Every GDT-registered company files a monthly tax return (combined monthly taxes) by the 20th of the following month, via E-Filing or the GDT Taxpayer App — even with no tax to pay.
- Two annual obligations fall on 31 March: the Tax on Income (TOI) return with the balance due, and the patent tax (annual business activity tax).
- Late = 10 / 25 / 40% additional tax depending on severity + interest (1.5 to 2% per month). Payment is built into E-Filing and partner banks (ABA, ACLEDA, Canadia).
How it works
The GDT (General Department of Taxation), under the MEF, groups most operating taxes into a single monthly tax return, plus two annual returns. Filing is done online via:
- E-Filing — the GDT web portal at tax.gov.kh/en/e-service.
- GDT Taxpayer App — the official mobile app (same company TIN login).
Payment is integrated: KHQR, ABA / ACLEDA / Canadia / J Trust Royal transfer, or direct debit from the corporate account.
Monthly calendar — filing on the 20th
The taxes below are grouped into the monthly tax return, filed and paid by the 20th of the following month. If the 20th falls on a Saturday, Sunday or public holiday, the deadline moves to the next working day (GDT rule / official calendar).
| Monthly tax | Base / indicative rate | Deadline | Applies to |
|---|---|---|---|
| Prepayment of TOI (1% of turnover) | 1% of monthly turnover, excl. VAT (GDT) | 20th of following month | Any company under the real regime |
| Tax on Salary (ToS) | Progressive 0–20% (residents) (GDT) | 20th of following month | Every employer (withheld at source) |
| VAT | 10% on liable sales (GDT) | 20th of following month | VAT-registered companies |
| Withholding tax (WHT) | 4 / 5 / 6 / 10 / 14% by payment type (GDT) | 20th of following month | Payers of rent, services, interest, etc. |
| Specific Tax | Rate per taxed product/service (GDT) | 20th of following month | Alcohol, tobacco, telecom, air tickets, etc. |
| Public Lighting Tax | 3% on alcohol & tobacco at each sale (GDT) | 20th of following month | Alcohol / tobacco distributors |
| Accommodation Tax | 2% on accommodation fees (GDT) | 20th of following month | Hotels, guesthouses, tourist lodging |
Annual calendar — 31 March
Two annual obligations fall on the same 31 March date (within 3 months of the financial year-end — 31 December for the vast majority of companies):
| Annual obligation | Deadline | Detail |
|---|---|---|
| Tax on Income (TOI) return + balance | 31 March | 20% of profit (or minimum tax 1% of turnover), less the 1% monthly prepayments already made; the balance is paid on this date (GDT) |
| Patent tax | 31 March | Flat annual activity tax of 400,000 / 1,200,000 / 3–5M KHR by category (GDT) |
The TOI balance = annual tax due − the sum of 1% prepayments already paid during the year. If your prepayments exceed the tax due, you build a tax credit carried forward (cash refunds are rare in practice).
E-filing: how to file
- Log in to E-Filing at tax.gov.kh/en/e-service (or open the GDT Taxpayer App) with the company TIN + password.
- Select the period (relevant month) and the return type (monthly or annual TOI).
- Enter the bases: monthly turnover, payroll (ToS), VAT collected / deductible, WHT bases, etc.
- The system computes the tax due and generates the payment notice (KHQR code).
- Pay before the 20th (monthly) / 31 March (annual) via partner bank or KHQR.
- Archive the filing acknowledgement + the payment receipt (keep for 10 years).
Late-filing penalties
A late filing or payment triggers, under the Law on Taxation, a progressive additional tax + interest:
| Situation | Penalty (additional tax) | Interest |
|---|---|---|
| Late / simple negligence | 10% | + 1.5–2% / month |
| Serious negligence (after notice) | 25% | + 1.5–2% / month |
| Obstruction / fraud / unilateral GDT assessment | 40% | + 1.5–2% / month |
The detail of the thresholds and their application is in the patent tax guide — late-payment penalties, which describes the same mechanism (10 / 25 / 40% + interest) for the 31 March deadline.
Common pitfalls
FAQ
What is the exact deadline for monthly returns?
The 20th of the following month, moved to the next working day if the 20th is a weekend or public holiday. Some professional sources mention a move to the 25th for E-Filing; absent official 2026 confirmation, aim for the 20th to be sure of avoiding a penalty — to be confirmed with the GDT.
Must I file even if my company invoiced nothing this month?
Yes. The nil return is mandatory every month while the company is active. Skipping it triggers the same penalties (10% + interest) as a late payment.
Are the annual TOI and the patent tax the same thing?
No. The TOI is the tax on profit (20%, or minimum 1% of turnover), settled on 31 March. The patent tax is a flat activity tax (400,000 to 5M KHR), also due on 31 March but independent of profit. Both fall on the same day. See the patent tax guide and the corporate income tax guide.
How do I pay once the return is filed?
E-Filing generates a notice with a KHQR code. You pay by KHQR scan, by transfer from your corporate account (ABA, ACLEDA, Canadia, J Trust Royal) or at a partner bank counter. Keep the official receipt with the filing acknowledgement.
What happens if I miss the 20th by a few days?
10% additional tax + interest (1.5–2% / month) on the tax due. It is recoverable without drama if you regularise quickly; beyond that, and after a formal notice, the penalty rises to 25% then 40%. Mechanism detailed in the patent tax guide.
Sources (4)
Every fact in this guide comes from official documents or government sites. An access date is recorded for each source.