Decree 254/2026/ND-CP, effective from 1 July 2026, requires sellers to show the foreign-currency-to-VND exchange rate on invoices, but it anchors that rate to the Law on Tax Administration and its implementing instruments without naming which rate. That open reference created at least two readings: the tax-filing rate, or the accounting rate.
On 14 September 2026, the Tax Department issued Official Letter No. 6810/CT-QLNT addressed to the Foreign Investment Enterprise Association, the Vietnam Association of Seafood Exporters and Producers, the Vietnam Pepper and Spice Association, the Korean Chamber of Business, and provincial tax authorities, to settle the interpretation.
In short
| Applies to | Which rate | |
|---|---|---|
| On the invoice | Economic and financial transactions arising in foreign currency | The actual transaction exchange rate determined under accounting law |
| When filing and paying tax | Cases eligible to file tax or other payments in foreign currency under clause 1, Article 14 of Decree No. 252/2026/ND-CP | The tax-filing conversion rate under Article 14 of Decree No. 252/2026/ND-CP |
The core point of the official letter is that it keeps these two rates as two separate limbs rather than merging them.
1. The underlying rule in Decree No. 254/2026/ND-CP
Point c.1, clause 8 of the Appendix to Decree No. 254/2026/ND-CP provides: where an economic or financial transaction arises in foreign currency under foreign exchange law, the unit price, amount, total VAT by tax rate, total VAT, and total payment amount are recorded in the foreign currency, with the currency unit named accordingly. The seller must also show on the invoice the exchange rate between the foreign currency and VND, at the rate set under the Law on Tax Administration and its implementing instruments.
Two adjacent points must be read alongside it:
- Point c.2: the currency code follows the international standard, for example 13,800.25 USD or 5,000.50 EUR.
- Point c.3: where the sale of goods arises in foreign currency under foreign exchange law and the seller is eligible to pay tax in foreign currency, the total payment amount is shown on the invoice in the foreign currency, with no conversion to VND required.
So the obligation to show the exchange rate under c.1 does not apply universally — c.3 is a clearly conditioned exception.
2. What Official Letter No. 6810/CT-QLNT instructs
The official letter also invokes clauses 1 and 5, Article 26 of the Law on Tax Administration No. 108/2025/QH15, under which an e-invoice is an invoice in electronic data form prepared by the seller to record information on the sale of goods or provision of services under both tax law and accounting law; and the seller must record the full content required by tax law and accounting law, ensuring the invoice fully and honestly reflects the economic transaction that occurred.
On that basis, the Tax Department concludes in two limbs:
First limb — currency and the tax-filing rate. For cases eligible to file tax or other payments in foreign currency under clause 1, Article 14 of Decree No. 252/2026/ND-CP, the currency used for filing and paying tax and other payments, and the tax-filing conversion rate, follow Article 14 of Decree No. 252/2026/ND-CP.
Second limb — the rate on the invoice. Where an economic or financial transaction arises in foreign currency under foreign exchange law, the seller shows the exchange rate between the foreign currency and VND on the invoice under point c.1, clause 8 of the Appendix to Decree No. 254/2026/ND-CP. Based on clauses 1 and 5, Article 26 of the Law on Tax Administration No. 108/2025/QH15 and accounting law, the rate shown on the invoice is the actual transaction exchange rate determined under accounting law.
3. Why separating the two limbs matters
The wording of point c.1 — “at the rate set under the Law on Tax Administration and its implementing instruments” — can easily lead a reader to infer that the invoice rate must be the tax-filing rate. Official Letter No. 6810/CT-QLNT does not go that route.
The Tax Department’s reasoning runs through Article 26 of the Law on Tax Administration: because an e-invoice is a document prepared under both tax law and accounting law, and because the invoice must honestly reflect the transaction that occurred, the rate shown on the invoice must be the rate of that specific transaction — that is, the actual transaction rate under accounting standards, not a conventional rate used for filing purposes.
The practical consequences for businesses:
- The rate on the invoice and the rate used when filing tax can differ, and that is not an error.
- There is no need to issue an adjustment invoice simply because the invoice rate does not match the period’s tax-filing rate.
- How to determine the actual transaction rate must be checked against the accounting regime the business applies, not against tax legislation.
4. Worked examples
Example 1 — Export, payment in foreign currency, tax paid in VND
Company A exports a USD 50,000 shipment under a contract settled in USD.
On the e-invoice, under point c.1, clause 8 of the Appendix to Decree No. 254/2026/ND-CP:
- The unit price, amount, and total payment are recorded in USD, with the currency unit shown as USD.
- The invoice also shows the USD/VND exchange rate.
- This rate follows the actual transaction rate determined under accounting law at the time the invoice is issued, per Official Letter No. 6810/CT-QLNT.
When preparing the tax return, if the company must convert to VND, that conversion follows the separate tax-filing rate rule. If the two figures differ, the company does not need to adjust the invoice — these are two figures serving two different purposes.
Example 2 — Eligible to pay tax in foreign currency
Company B sells goods arising in foreign currency under foreign exchange law and is eligible to pay tax in foreign currency.
Under point c.3, clause 8 of the Appendix to Decree No. 254/2026/ND-CP, the total payment amount is shown on the invoice in the foreign currency and does not need to be converted to VND. This is the only scenario under this provision that is exempted from the conversion obligation.
Both conditions must be met at once: the transaction arises in foreign currency under foreign exchange law, and the company is eligible to pay tax in foreign currency. Missing the second condition reverts to the general rule under c.1.
5. What businesses should do now
- Review the invoicing software configuration. Check which exchange-rate source the system pulls automatically. Many systems are configured to the tax-filing rate or the central rate — this should be reconciled against the actual transaction rate under the applicable accounting regime.
- Align the exchange-rate source between the accounting team and the invoicing team. The Tax Department’s guidance anchors the invoice rate to the accounting source, so both teams need to follow the same rule.
- Document the exchange-rate determination rule in internal procedures, citing Official Letter No. 6810/CT-QLNT, to have a basis for explanation during inspection or audit.
- Confirm whether the company falls under the c.3 exception before omitting the conversion on the invoice. Misapplying c.3 is a risk to invoice content.
- Review foreign-currency invoices issued since 1 July 2026, as this is the transition period into Decree No. 254/2026/ND-CP and also the period in which the issue prompting this official letter arose.
6. A technical note on citation
Official Letter No. 6810/CT-QLNT cites this rule two different ways in two places: the opening citation reads “point c.1, clause 8, Article 10 of Decree No. 254/2026/ND-CP”, while the concluding section reads “point c.1, clause 8 of the Appendix to Decree No. 254/2026/ND-CP”.
Checking against Decree No. 254/2026/ND-CP, the second citation is the accurate one: clause 2 of Article 10 only states the heading “Script, numerals and currency shown on the invoice”, while clause 3 delegates the detailed content to the Appendix; the exchange-rate provision sits at point c.1, clause 8 of that Appendix. When citing this rule in filings, explanatory documents, or correspondence with the tax authority, businesses should use the Appendix-based citation.
Disclaimer
This article is based on:
- Official Letter No. 6810/CT-QLNT dated 14 September 2026 of the Tax Department, guiding the exchange rate shown on invoices;
- Decree No. 254/2026/ND-CP dated 30 June 2026, detailing certain articles and measures to implement the Law on Tax Administration No. 108/2025/QH15 on e-invoices and electronic documents (effective from 1 July 2026, replacing Decree No. 123/2020/ND-CP, Article 1 of Decree No. 41/2022/ND-CP, and Decree No. 70/2025/ND-CP);
- Circular No. 91/2026/TT-BTC dated 30 June 2026 (effective from 1 July 2026);
- Clauses 1 and 5, Article 26 of the Law on Tax Administration No. 108/2025/QH15, as cited in Official Letter No. 6810/CT-QLNT.
Three matters fall outside the scope of the above documents and require separate checking before application to a specific case:
- How to determine the actual transaction exchange rate, which falls under accounting law. The official letter refers to accounting law without specifying the calculation method, so businesses must rely on their applicable accounting regime.
- Article 14 of Decree No. 252/2026/ND-CP on the currency for filing and paying tax and the tax-filing conversion rate — this document has not been cross-checked in this article.
- The rules on eligibility to pay tax in foreign currency, which form the condition for applying point c.3, under tax administration law and foreign exchange law.
A tax authority’s guidance letter is not a legal normative document; it has interpretive value and is issued based on the legal provisions in force at the time of issuance.
This article is for reference only, does not replace the original legal documents, and does not constitute advice for any specific transaction. Businesses should check against the legislation in force at the time of application and consult a qualified advisor before making decisions.
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