A dollar invoice with no riel total is incomplete
Cambodia runs on two currencies. Rent is often quoted in dollars, salaries are often paid in riel, and a market stall will quote one price in whichever currency the customer is holding. It is natural to invoice in dollars and stop there.
For registered self-assessment taxpayers, stopping there is not allowed. Notification 4908 GDT, dated 18 March 2019, requires the total amount payable — including VAT — to be shown in Khmer riel on invoices. Line amounts may remain in another currency. The total may not.
This is one of the most commonly missed requirements in Cambodian invoicing, and it is not a formatting preference. A dollar invoice that never states the riel total does not meet the notification.
What exactly must be in riel
- The total amount payable, including VAT, in KHR.
- It must appear on the invoice, not only in your accounting system.
- Line amounts — descriptions, quantities, unit prices — may stay in the currency you trade in.
In practice: a USD-denominated invoice is legal and normal. It just needs its grand total restated in riel, with the rate stated.
Which exchange rate you may use
Notification 4908 gives two acceptable sources, and you choose:
- The GDT's published monthly rate for the previous month. Fixed for the month, published by the General Department of Taxation, and identical across every invoice you issue that month. Predictable, easy to defend, and easy to check.
- A market rate, provided it is not lower than the National Bank of Cambodia daily rate. If you use the day's market rate, it may be above the NBC reference rate but never below it. Using a rate below the official one understates the riel amount, which is exactly what the notification is guarding against.
The National Bank of Cambodia publishes an official reference rate every business day. The GDT's monthly rate is published for the previous month, so a January invoice uses the December rate.
Rounding
Notification 4908 also settles rounding, which saves an argument with every accountant:
- A remainder above 0.5 riel rounds up to the next whole riel.
- A remainder below 0.5 riel rounds down.
So USD 1,234.56 at a rate of 4,100 KHR per dollar converts to 5,061,696 KHR exactly, while 5,061,696.4 rounds down to 5,061,696 and 5,061,696.6 rounds up to 5,061,697.
Why this requirement exists
The riel is the national currency, and tax is assessed and paid in riel. If a business invoices in dollars and never states the riel equivalent, the amount of tax due depends on whichever rate someone applies later. Notification 4908 removes that ambiguity by putting the conversion on the document, with the rate and date visible.
The practical workflow
- Invoice in the currency you actually trade in.
- Convert the grand total, including VAT to riel.
- Use the GDT monthly rate for the previous month, or a market rate not lower than the NBC daily rate.
- Print the riel total, the rate used, and the date of the rate on the invoice.
Check the current official rate before you issue the document. The Cambodia Exchange Rates tool publishes the National Bank of Cambodia daily rate, its source and its date, so you can compare your own rate against the official one rather than relying on a screenshot from last month.
The Cambodia Invoice Generator resolves the NBC daily bulletin at render time and stamps the rate and its bulletin date on the finished PDF, so the conversion is visible on the document itself rather than only in your records. It handles the rounding rule above, and it applies the riel total to the grand total including VAT — not to the subtotal.
Common questions
Does this apply to small taxpayers? Notification 4908 addresses registered self-assessment taxpayers — medium and large. If you are a small taxpayer issuing commercial invoices, the riel total is not imposed on you by this notification. Showing it anyway is not wrong, and in a cash-heavy riel economy it is often what your customer wants to see.
Can I use a rate that is more favourable? You may use a market rate only if it is not lower than the NBC daily rate. A higher rate is permitted; a lower one is not.
Can I use the rate from the day I got paid instead of the invoice date? The notification does not say the rate must be from the invoice date. What it requires is that the riel total appears and that the rate used is one of the two permitted sources. State which rate and which date you used, and the document is checkable.
What if my bank uses a different rate? Banks apply their own buying and selling rates, which differ from the NBC reference rate. The reference rate is the floor the notification refers to; your bank's rate is a commercial rate for a specific transaction. They are not the same number, and they are not meant to be.
Does the riel total need to be in Khmer numerals? The requirement is that Khmer is used and any foreign language appears below it, per Instruction 3033 / Notification 3218 (6 February 2020). The riel total is a figure on the document like any other — put it in the Khmer block, above its English counterpart.
What to remember
- Notification 4908 GDT, 18 March 2019 — the total payable, including VAT, in KHR.
- Line amounts may stay in dollars.
- Two permitted rates: the GDT monthly rate for the previous month, or a market rate not lower than the NBC daily rate.
- Rounding: above 0.5 riel up, below 0.5 riel down.
- Put the rate and its date on the invoice.
This article explains the rule; it is not tax advice. Confirm your own treatment with the General Department of Taxation or a qualified adviser.