Bilingual invoicing for FDI subsidiaries in Vietnam — what HQ needs to know

Every FDI subsidiary in Vietnam runs into the same problem eventually: your accounting team in Hanoi or HCMC issues a perfectly compliant Vietnamese VAT invoice; your controller in Tokyo, Seoul, or Singapore opens the PDF and can't read a single line. They email back asking for “the English version,” the accounting team produces a Word document copy, and you now have two unrelated artifacts — one official (in Vietnamese), one for HQ (informal, unaudited).

This works until your annual audit, when the auditor asks for the supporting documents for a related-party transaction. The Vietnamese invoice and the “HQ copy” don't reconcile because they were generated separately. The auditor flags it. Painful.

The fix is in the regulation: TT 78, Article 10

Circular 78/2021/TT-BTC explicitly allows bilingual invoices. Article 10, Clause 1(c) permits invoices to display content in “Vietnamese accompanied by a foreign language,” provided the Vietnamese text is the authoritative version and the foreign-language text appears alongside (not in place of) it.

The implementing guidance from the General Department of Taxation has been consistent: a bilingual invoice with Vietnamese in column A and your HQ language in column B (English, Japanese, Korean, Chinese) is a single document that is simultaneously compliant for tax purposes and readable by your overseas controller.

The key constraints:

• Vietnamese must be present— it's the authoritative language for any tax authority interpretation.
• The foreign-language text must be a faithful translation— no discrepancies in amounts, dates, line items, parties, or tax classification.
• The bilingual presentation must be visually unambiguous— side by side, or one below the other, with clear visual separation. Avoid mixed-sentence layouts.
• The GDT-issued authentication code (TT 78 §7)still has to be embedded; bilingual presentation doesn't change the authentication mechanism.

What the practical layout looks like

est-invoice ships three bilingual layouts out of the box, tuned for the three most common FDI HQ languages:

1. Japanese ⇄ Vietnamese— vertical split (left: Vietnamese, right: Japanese), JCCI procurement-tested with member companies.
2. Korean ⇄ Vietnamese— vertical split, KOCHAM-style. Hangul characters render cleanly at A4 portrait, no spacing issues.
3. English ⇄ Vietnamese— covers Singapore, US, UK, Australia, EU subsidiaries.
4. Chinese (Simplified) ⇄ Vietnamese— same vertical split, handles both mainland-Chinese and Taiwanese subsidiary use cases. (Most TW subsidiaries use Simplified for VN-facing documents per our customer interviews.)

Each layout uses a single source of truth: the invoice data model. The Vietnamese rendering and the foreign-language rendering are both derived from the same fields, so there is no possibility of divergence. If you change the unit price, both sides update; you cannot accidentally have $1,000 USD on the English side and 24,000,000 VND on the Vietnamese side from a stale translation.

What HQ actually wants on the “HQ side”

We interviewed 12 FDI controllers (Japan, Korea, Singapore, US) about what they actually want to see on the foreign-language side of a Vietnamese invoice. Consensus:

• Counterparty name in the original script— not transliterated. A Japanese controller wants “株式会社XYZ”, not “Kabushiki Kaisha XYZ”.
• Amounts in the HQ's reporting currency, with the VND amount and FX rate shown alongside — auditable, not just a converted number.
• VAT rate explicitly stated, with the Vietnamese tax classification code (e.g. “VAT 10% — standard rate, Circular 219/2013 Art.10”).
• Bank account details for any wire instructions, in both the Vietnamese SWIFT format and a HQ-friendly layout.
• Reference to the underlying contract so the controller can match the invoice to the right purchase order or service agreement.

Contracts and quotes deserve the same treatment

Bilingual presentation isn't just about invoices. The same logic applies to contracts, purchase orders, quotes, and acceptance reports — every document that crosses the Vietnam-HQ boundary should be one bilingual artifact, not two translations.

est-invoice ships parallel-column templates for:

• Service contracts + addenda (with negotiable clauses highlighted)
• Purchase orders (with HQ-currency totals + VND totals + FX rate)
• Quotes (with validity dates in both calendars where relevant — e.g. JP fiscal year)
• Acceptance reports / handover certificates (with signature blocks for both sides)

Migration: what to do if you already have a mess

If you've been running on the “Vietnamese invoice + informal English Word doc” pattern, here's the practical migration path:

1. Audit your last 12 months of invoices for translation drift. Compare the Vietnamese invoice to whatever was sent to HQ. Common findings: stale prices, wrong tax codes, wrong counterparty names, missing line items.
2. Migrate your invoice template to bilingual once.Future invoices generate as bilingual from day one — no more parallel artifacts.
3. For historical invoices that have already been issued, you can retroactively generate a bilingual PDF from the existing GDT-authenticated invoice data; the GDT code stays valid, the bilingual presentation is a re-rendering, not a new invoice.
4. Brief your auditor. Big-4 partners (KPMG, PwC, Deloitte, EY) all have FDI-experienced teams in Vietnam; bilingual invoices speed up their audit and reduce sample-and-translate friction.

One artifact, two readers

The principle is simple: one invoice, two readers (Vietnamese tax authority + HQ controller), zero translation drift. Vietnamese regulation explicitly supports this; the tooling just has to follow.

If you'd like to see the est-invoice bilingual templates in action, the demo at est-invoice.com/demo walks through the JA/KO/EN/ZH layouts with real (anonymized) data. For a country-specific deep dive, see our guides for Japanese, Korean, Chinese / Taiwanese, and Thai companies in Vietnam.