E-Invoice Compliance in Vietnam (Decree 123): 2026 Guide for FDI Companies

Introduction: Vietnam’s Digital Transformation of Invoicing

Vietnam has firmly committed to modernizing its tax administration through mandatory electronic invoicing. Under Decree No. 123/2020/NĐ-CP (commonly referred to as NĐ 123), effective from July 1, 2022, all enterprises, business households, and individuals doing business in Vietnam must use electronic invoices (e-invoices or hóa đơn điện tử) for every sale of goods and provision of services. For foreign-invested enterprises (FDI companies), understanding and implementing e-invoice compliance is not optional — it is a legal requirement with significant penalties for non-compliance.

As of 2026, the General Department of Taxation (GDT) has fully enforced the e-invoice system nationwide. This guide — prepared by Dịch Vụ Kế Toán Á Châu‘s FDI advisory team — walks you through everything your company needs to know about e-invoice compliance in Vietnam, from registration to ongoing obligations, common pitfalls, and best practices that keep your accounting operations running smoothly.

Legal Framework: NĐ 123/2020/NĐ-CP and Circular 78/2021/TT-BTC

The legal backbone of Vietnam’s e-invoice system rests on two primary documents:

• Decree No. 123/2020/NĐ-CP (October 19, 2020): Regulates invoices and documents. It replaced Decree 119/2018/NĐ-CP and Decree 51/2010/NĐ-CP, unifying the rules for all types of invoices — electronic and paper — under one framework.
• Circular No. 78/2021/TT-BTC (September 17, 2021): Provides detailed implementation guidance for Decree 123, including e-invoice formats, data transmission standards, registration procedures, and conversion rules for existing paper invoices.

Additionally, the official e-invoice standard format is defined by Decision No. 1450/QĐ-TCT issued by the General Department of Taxation, which specifies the XML schema (UBL 2.1-based) that all e-invoice service providers must follow. For the latest updates, FDI companies should regularly consult the Ministry of Finance portal and the National Legal Database (vbpl.vn).

Who Must Use E-Invoices in Vietnam?

Under Article 4 of Decree 123, the e-invoice obligation applies to:

• All enterprises (including FDI companies, representative offices, and branches) established under Vietnamese law
• Business households and individuals engaged in commercial activities
• Organizations and individuals selling goods or providing services

There are limited exemptions. Article 12 of Decree 123 lists specific cases where paper invoices may still be used, primarily for businesses operating in areas without internet access or electricity, subject to tax authority approval. However, for the vast majority of FDI companies operating in urban and industrial zones, e-invoices are compulsory.

Types of E-Invoices in Vietnam

Vietnam’s e-invoice system recognizes several distinct types, each serving a specific purpose:

1. E-Invoices with Tax Authority Codes (CQT)

These e-invoices receive a unique verification code issued by the tax authority’s system before they become valid. This applies primarily to high-risk taxpayers and newly established enterprises during their first 12 months of operation. The tax authority’s system checks the invoice data and issues a code within the same day of submission.

2. E-Invoices without Tax Authority Codes

Most established FDI companies fall into this category. The enterprise generates invoices through an accredited e-invoice service provider (T-VAN) and transmits summary data to the tax authority, but the invoice is valid upon issuance by the enterprise — no pre-approval code is required.

3. Electronic Records for Goods Sold at Retail

For B2C retail transactions (supermarkets, restaurants, retail stores), businesses may use electronic records generated from cash registers connected to the tax authority’s data system, as an alternative to individual e-invoices for each transaction. This is governed by Article 8 of Decree 123.

4. Specific-Purpose E-Invoices

Specialized formats exist for: export activities (customs e-invoices), petroleum products, electricity distribution, telecommunications, insurance, banking, securities, air transport, and healthcare services — each with sector-specific data fields.

E-Invoice Registration Process for FDI Companies

Registering for e-invoice issuance involves several administrative steps. Here is the standard workflow:

Step 1: Select an Accredited E-Invoice Service Provider (T-VAN)

Vietnam’s GDT maintains a list of authorized e-invoice service providers. Your company must contract with one of these providers to transmit invoice data to the tax authority. Key providers include Viettel, VNPT, MISA, BKAV, Thai Son, and FPT. Selection criteria should include: integration capability with your existing ERP/accounting software, support for English-language interfaces, data retention commitments, and pricing.

Step 2: Prepare and Submit Registration (Form 01/ĐKTĐ-HĐĐT)

The enterprise submits Form 01/ĐKTĐ-HĐĐT (Appendix IA, Decree 123) via the tax authority’s electronic portal (thuedientu.gdt.gov.vn). This form declares:

• Enterprise information (tax code, registered address, business lines)
• Selected e-invoice service provider
• Type of e-invoice (with or without tax authority codes)
• Invoice series for each business activity
• Start date for e-invoice usage
• Digital signature certificate details

Step 3: Tax Authority Review and Approval

The tax authority reviews the registration within 1 working day. If the registration is valid, the authority issues a notification of acceptance. If there are errors or missing information, the enterprise receives a notice requesting corrections within 2 working days.

Step 4: Configure and Integrate Systems

Once approved, your e-invoice service provider will configure the system, integrate with your accounting software (or provide a standalone portal), and enable digital signing. All e-invoices must be digitally signed using a valid digital certificate issued by a licensed CA in Vietnam.

Step 5: Notify Clients and Transition

Before issuing your first e-invoice, you must notify buyers of the transition. The tax authority also publishes your e-invoice registration status on its portal. Any remaining unused paper invoices must be reported and destroyed according to the prescribed procedure.

Data Transmission Requirements

Under Circular 78/2021/TT-BTC, key transmission obligations include:

• Invoice data transmission: E-invoices without tax authority codes must have summary data transmitted to the tax authority on the same day of issuance (for invoices with codes, transmission occurs during the code-issuance step).
• Error correction: If errors are discovered after transmission, corrections must follow strict procedures (adjustment invoices or replacement invoices, depending on the error type).
• Data retention: E-invoice data and the underlying XML files must be retained for at least 10 years, consistent with accounting law requirements.

Common Compliance Challenges for FDI Companies

From our experience at Á Châu Accounting Services, the following issues frequently affect foreign enterprises navigating Vietnam’s e-invoice system:

1. ERP-to-E-Invoice Integration

Many FDI companies use global ERP systems (SAP, Oracle, Microsoft Dynamics) that are not natively compatible with Vietnam’s UBL 2.1 XML schema. Building custom middleware or adopting a local bridging solution is often necessary — and time-consuming if not planned early.

2. Digital Signature Requirements

Vietnam requires e-invoices to be signed with a locally issued digital certificate. Foreign digital certificates (even those from globally recognized CAs) are not accepted. Your company must obtain a digital certificate from one of Vietnam’s licensed CAs — this is a prerequisite that is sometimes overlooked during market entry.

3. Invoice Series Management Across Multiple Activities

If your FDI company operates across multiple business lines (e.g., manufacturing, trading, and services), you must register separate invoice series for each activity type. Mixing invoice series across activities results in invalid invoices and potential penalties.

4. Handling Vietnamese-Language Requirements

While e-invoices may include a foreign language alongside Vietnamese, the Vietnamese text is mandatory and is considered the official version. FDI companies that operate primarily in English or another language must ensure all invoice fields are correctly presented in Vietnamese — including item descriptions, units of measurement, and tax calculations.

5. Cross-Border Service Invoicing

For services provided to overseas clients, the e-invoice obligation still applies. However, timing and currency considerations add complexity: the invoice date must reflect Vietnam time, and the exchange rate for VND conversion must follow the tax authority’s published rates for the transaction date.

Penalties for E-Invoice Non-Compliance

The consequences of failing to comply with Vietnam’s e-invoice regulations can be severe. Penalties are governed by Decree No. 125/2020/NĐ-CP (amended by Decree 102/2021/NĐ-CP) and include:

Beyond monetary fines, non-compliance can trigger tax audits, damage your company’s tax compliance rating, and create complications during annual financial statement reviews or tax finalization processes. For FDI companies that rely on tax compliance certificates for various administrative procedures, the indirect costs of non-compliance far exceed the direct penalties.

Best Practices for E-Invoice Compliance

1. Engage a Qualified Local Accounting Partner

Vietnam’s tax environment changes frequently. A professional accounting service provider with FDI expertise — such as Á Châu — can handle e-invoice registration, ongoing compliance, error correction, and reconciliation, allowing your management team to focus on core business operations.

2. Conduct Periodic Self-Audits

Quarterly reviews of your e-invoice data against tax declarations help catch discrepancies before the tax authority does. Verify that:

• All revenue is properly invoiced with correct invoice series
• Invoice data transmitted to the tax authority matches your accounting records
• Error corrections (adjustment/replacement invoices) are properly documented
• Digital signatures have not expired

3. Train Your Accounting Team

Ensure both Vietnamese and expatriate accounting staff understand the e-invoice workflow, common error scenarios, and correction procedures. Many compliance failures stem not from intent but from unfamiliarity with the Vietnamese-specific requirements.

4. Stay Updated on Regulatory Changes

The GDT regularly issues Official Letters (Công văn) clarifying and updating e-invoice requirements. Subscribe to updates from your e-invoice service provider and your accounting advisory partner. For networking and staying connected with Vietnam’s business community, platforms like BizCA.vn provide valuable updates and peer connections.

E-Invoice Integration with VAT and CIT Reporting

E-invoice data is not isolated — it flows directly into your company’s VAT declarations and CIT finalization. The tax authority’s system cross-references:

• Output VAT: E-invoice data (sales) against VAT declarations (Form 01/GTGT)
• Input VAT: Counterparty e-invoice data (purchases) against your declared input VAT
• Revenue: E-invoice totals against CIT finalization figures
• Withholding tax: E-invoices issued to foreign contractors against foreign contractor tax declarations

Discrepancies between any of these data sets will automatically flag your company for tax inspection. This integration makes accurate e-invoicing essential not only for compliance with Decree 123 but for your company’s overall tax position in Vietnam.

Frequently Asked Questions (FAQ)

Q1: Can FDI companies continue using paper invoices in Vietnam?

No. As of July 1, 2022, all enterprises in Vietnam — including FDI companies — must use e-invoices. Paper invoices are only permitted in very limited circumstances (e.g., areas without reliable internet connectivity) and require specific tax authority approval. Your company cannot unilaterally decide to use paper invoices.

Q2: What happens if an e-invoice contains an error after it has been issued?

Errors are corrected through one of two methods: (1) an adjustment invoice (hóa đơn điều chỉnh) that references the original invoice and corrects the error, or (2) a replacement invoice (hóa đơn thay thế) that fully replaces the original — which is then voided. The choice depends on the type of error. Both correction types must be transmitted to the tax authority, and the original invoice must be referenced by its unique code (Ký hiệu mẫu số hóa đơn and Ký hiệu hóa đơn).

Q3: Are there English-language e-invoice service providers in Vietnam?

Yes. Several major providers — including Viettel, MISA, and FPT — offer English-language interfaces for their e-invoice portals. However, the invoice content itself (item descriptions, company names, addresses) must include Vietnamese text as the primary language. English can appear as a supplementary translation but is not recognized as the official version by tax authorities.

Q4: How long must FDI companies retain e-invoice records?

Under Vietnam’s Accounting Law (Law No. 88/2015/QH13) and Decree 123, e-invoice data — including the original XML files and all supporting documents — must be retained for a minimum of 10 years. This applies even if the company ceases operations or is dissolved. The retention obligation extends to both the enterprise and the e-invoice service provider.

Q5: Can an FDI company use its global ERP to issue Vietnamese e-invoices directly?

It depends on the ERP. Most global systems (SAP, Oracle, Microsoft Dynamics) do not natively support Vietnam’s UBL 2.1 XML schema as required by Decision 1450/QĐ-TCT. Typically, a middleware layer or a custom integration module is needed to bridge the ERP with a certified T-VAN provider. Á Châu’s accounting team can advise on integration strategies and help coordinate with your IT department and service provider.

Conclusion: Proactive Compliance Is the Smartest Strategy

Vietnam’s e-invoice mandate under Decree 123 is a comprehensive regulatory framework that touches every revenue transaction your FDI company conducts. While the transition requires upfront investment in systems and processes, the long-term benefits — streamlined tax reporting, reduced paperwork, improved data accuracy, and a stronger compliance posture — far outweigh the costs.

At Dịch Vụ Kế Toán Á Châu, we specialize in helping foreign-invested enterprises navigate Vietnam’s accounting and tax landscape. From e-invoice registration and integration to ongoing compliance management, our bilingual team ensures your company stays compliant while you focus on growing your business. Contact us today for a consultation on your e-invoice compliance needs, or explore our full range of FDI accounting services at taichinhachau.com. For networking and business insights, join our community at BizCA.vn.