If you are deciding between an adjustment invoice and a replacement invoice in Vietnam, start with the error type. Since July 1, 2026, the rules sit in Article 10 of Circular 91/2026/TT-BTC, which carries the correction detail for Decree 254/2026/ND-CP. An issued e-invoice that is wrong only in the buyer's name, the address or the amount in words is handled by notifying the buyer and sending Form 04/SS-HDDT to the tax authority, not by issuing a new invoice. If the error affects the tax code, the goods, amounts, the tax rate, the tax amount or other mandatory details, you move into a correction path that requires either an adjustment or a replacement, and invoices generated from cash registers or issued for assets whose ownership must be registered can only be replaced. When the same incorrect information appears on multiple invoices issued in the same month to the same buyer, one adjustment or replacement invoice may cover all of them. For business buyers, the parties must prepare a written agreement before an adjustment or replacement. For individual buyers, the seller must notify the buyer or publish the notice on its website if it has one.
That is the short answer to the Vietnam e-invoice adjustment vs replacement question. The harder part is turning that answer into a workflow your team can follow under time pressure, especially when billing, tax, and ERP teams all need the same correction file to make sense.
The fastest way to work through Vietnam's adjustment and replacement rules is to sort every issued invoice error into three buckets:
- Notify only when the mistake is limited to the buyer's name, address or the amount in words and the tax code plus the transactional details remain correct.
- Adjust when the original invoice should remain part of the record but specific figures or details need to be corrected through a linked follow-on document.
- Replace when it is cleaner to supersede the incorrect invoice with a corrected invoice that still points back to the original. For cash-register invoices and invoices for registered assets, replacement is the only option.
This article is written as a finance-team decision guide, not a general summary of Vietnam's invoice rules. The goal is to help you classify a wrong issued invoice quickly, decide whether Vietnam e-invoice error correction should be handled through notice, adjustment, or replacement, and keep the resulting audit trail defensible for accounting and tax review.
Which Rules Govern E-Invoice Corrections Since July 2026
The biggest reason this topic causes confusion is that many teams still think in terms of the older cancellation logic. Decree 70/2025/ND-CP removed cancellation of incorrect e-invoices from June 1, 2025, and the rules in force since July 1, 2026 did not bring it back. The operator's question has moved away from "Can I cancel this invoice?" and toward "Does this error only need notice, or does it require an adjusted or replacement invoice?"
That sounds like a small wording change, but it changes how finance teams build correction workflows. A broad regulatory summary may mention the amendment, yet still leave AP or AR teams without a usable decision path. Your process has to start with the status of the issued invoice, the nature of the error, and the documentary consequences of correcting it.
The legal basis has moved too. As EY Vietnam's tax alert on Decree 254 and Circular 91 sets out, Decree 254/2026/ND-CP replaced Decree 123/2020/ND-CP and its Decree 70 amendments, and it no longer contains detailed rules on replacing and adjusting e-invoices. It leaves them to the Minister of Finance, and they now sit in Article 10 of Circular 91/2026/TT-BTC. Most of the mechanics carried over. A correction workflow built on the Decree 70 rules needs four updates:
- The legal reference. Corrections made since July 1, 2026 rest on Circular 91, Article 10, not on Article 19 of Decree 123.
- The amount in words is notify-only. It now sits with the buyer's name and address in the notice branch, provided the tax code, amounts, tax rate, tax amount and goods are correct.
- Some invoices can only be replaced. Invoices generated from cash registers and invoices for assets subject to ownership or use-right registration cannot be adjusted.
- Declaration timing is no longer fixed to the original period. The rule placing error corrections in the original invoice's tax period is gone (see the declaration section below).
Invoices issued under Decree 123, Decree 70 and Circular 32/2025/TT-BTC that turn out to be wrong after July 1, 2026 are adjusted or replaced under the new rules (Circular 91, Article 24).
This is why the topic should be separated from Vietnam's wider e-invoice requirements. The national regime explains who issues e-invoices and under what rules. A Vietnam Circular 91 e-invoice correction workflow deals with a narrower operational problem: the invoice already exists, it is wrong, and you need the correct remedy without breaking the audit trail.
If you keep that shift in mind, the rest of the decision becomes much clearer. First determine whether the issue is trivial enough for notice only. If it is not, decide whether the original invoice should stay in place and be adjusted, or whether it should be superseded by a replacement.
When You Only Notify Instead of Issuing a New Invoice
The cleanest branch in the workflow is the notify-only case. If the issued invoice is wrong only in details such as the buyer's name, the address or the amount in words, while the tax code, the amounts, the tax rate, the tax amount and the goods remain correct, the seller does not need to issue a new invoice. Instead, the seller notifies the buyer and sends Form 04/SS-HDDT to the tax authority, whose system confirms receipt automatically.
That distinction matters because it prevents unnecessary reissuance. A team that treats every typo as a full correction event creates avoidable downstream work in ledgers, reconciliations, and document archives. The first question should therefore be: does this mistake change who was taxed, what was supplied, or how much was invoiced? If the answer is no, and the problem is limited to details such as the buyer's name, the address or the amount in words, you are usually still in the notice branch rather than the reissue branch.
This is also the point where finance teams should classify the incorrect issued invoice carefully. A wrong buyer name looks minor, but a wrong buyer tax code does not belong in the same category. Likewise, a goods description error that changes the commercial meaning of the invoice is not just an administrative typo. Once the error affects tax identity, values, tax amounts, or the substance of the transaction, you have moved beyond a Vietnam buyer notice for invoice errors and into adjustment-or-replacement territory.
From a control perspective, the notice step should be documented, not treated as a casual email fix. Teams should preserve the buyer communication, the internal classification of the error, and the Form 04/SS-HDDT sent to the tax authority with its receipt. That way, if the file is reviewed later, you can show why no new invoice was issued and why the issue was treated as a limited-data correction rather than a substantive invoice rewrite. Sellers that send invoice data to the tax authority on the consolidated summary of e-invoice data skip the form: they report any correction on a later period's summary instead.
When an Adjustment Invoice Is the Better Fix
An adjusted e-invoice is usually the better tool when the original invoice should remain part of the record, but one or more details need to be corrected through a linked follow-on document. In other words, you are not pretending the first invoice never existed. You are preserving it, then recording the correction against it in a traceable way.
That logic is especially useful when values need to move up or down. An adjustment invoice showing positive or negative amounts should make the change explicit, not leave reviewers guessing whether the corrected figures replace the original values or represent only the delta. Finance teams often prefer adjustment where the audit question is "what changed?" rather than "what is the entirely restated invoice?"
The adjusted invoice has to identify the original incorrect invoice and state that it adjusts it. Circular 91 prescribes the line "Điều chỉnh cho hóa đơn Mẫu số… ký hiệu… số… ngày… tháng… năm…", which reads "this invoice adjusts invoice form…, serial…, number…, dated…", so the file makes sense on its own without extra explanation. This notation matters because the documentary chain has to be understandable to tax reviewers, auditors, and anyone reconciling the correction in an ERP or spreadsheet export. If your team cannot see the reference back to the original invoice immediately, the file will be harder to defend later.
Adjustment also fits well when the business wants to preserve the original commercial document sequence but fix amounts, tax elements, or other data points through a controlled follow-up entry. Circular 91 requires increases to be shown as positive amounts and decreases as negative ones, so teams should be disciplined about how each change is shown. If a value rises, the adjustment should show the upward correction clearly. If a value falls, the adjustment should reflect the negative change clearly. Ambiguous wording creates avoidable confusion in later VAT reporting and ledger review.
Adjustment is not always available: cash-register invoices and invoices for registered assets can only be replaced, as the next section explains. Within that limit, adjustment works best when you need a visible, linked correction that preserves the original invoice history and makes the numerical change easy to trace.
When a Replacement Invoice Is Better, Including Same-Month Batch Corrections
A replacement e-invoice is often the cleaner option when the original issued invoice should be superseded by a corrected version rather than adjusted through separate positive or negative changes. Operationally, replacement is useful when the team wants one corrected invoice record to stand in place of the wrong one, while still maintaining a reference back to the original.
That reference is not optional housekeeping. Vietnam replacement invoice notation needs to make the relationship to the incorrect invoice obvious and state that the new invoice replaces it: Circular 91 prescribes the line "Thay thế cho hóa đơn Mẫu số… ký hiệu… số… ngày… tháng… năm…", which reads "this invoice replaces invoice form…, serial…, number…, dated…". A reviewer should be able to identify which invoice is being replaced without reconstructing the story from email threads or internal notes. The replacement invoice therefore needs clear linkage to the original incorrect invoice so the documentary trail remains intact.
For two kinds of invoice, replacement is the rule rather than a choice: invoices generated from cash registers connected to the tax authority (covered in our guide to Vietnam's cash-register e-invoice requirements) and invoices for goods that are assets subject to ownership or use-right registration, such as vehicles. The carve-out is a returned asset already registered in the buyer's name: there, a buyer that uses e-invoices issues its own invoice returning the goods to the seller.
Same-month batching works with either remedy. For a Vietnam same-month e-invoice correction, where the seller made the same error in the buyer's details, the goods name, the unit price, the quantity or the tax rate on several invoices to the same buyer in one month, one adjustment or replacement invoice may cover all of them, with the erroneous invoices listed on Form 01/BK-DCTT. This is useful when a recurring data issue, such as the same wrong tax rate or a repeated product-field mistake, affected a batch of invoices before the error was discovered.
Even so, batching should be used with care. If the invoices have different error patterns, different commercial facts, or different correction logic, separate correction documents may be safer. The goal is not to compress paperwork at any cost. The goal is to create a file that clearly shows what was wrong, what corrected or replaced it, and why the grouped correction makes sense.
The simplest way to distinguish replacement from adjustment is this: replacement restates the corrected invoice record, while adjustment preserves the original and records the change against it. If your team needs a fully corrected substitute document, replacement is often the better fit. If your team needs to preserve the original and highlight the delta, adjustment is usually more natural.
How to Choose Between Adjustment and Replacement
Where the law leaves the choice to the seller, work through these questions in order:
- Is the method already decided? Cash-register invoices and invoices for registered assets must be replaced. An invoice lawfully issued without a form number, serial and invoice number can only be adjusted.
- Has this invoice been corrected before? If an adjusted or replaced invoice turns out to be wrong as well, Circular 91 requires the next correction to use the same method as the first.
- What does the error do to the record? A single wrong value, such as a price, a quantity or a tax amount, reads clearly as an adjustment showing the delta. Errors spread across several fields, or a wrong tax code, usually read more cleanly as a replacement that restates the whole invoice.
- What will the buyer accept? A business buyer has to agree the error in writing before either document is issued, so settle the method in that agreement. The buyer's ledger has to absorb the correction too.
- Which tax period will the correction land in? Circular 91 does not fix the declaration period for error corrections, so check it against VAT and tax administration law before issuing, particularly where the original invoice already sits in a filed return.
Documentation, Declaration Timing, and a Clean Audit Trail
Once you know whether the invoice should be notified, adjusted, or replaced, the last job is to make the correction defensible. For business buyers (organizations, business households and business individuals), that means a written agreement clearly stating the errors before issuing an adjustment or replacement invoice, kept on file for the tax authority. No agreement is needed where invoice data reaches the tax authority on the consolidated summary of e-invoice data, where transaction data is sent as a summary of detailed transaction information, or for sales on e-commerce and other digital platforms. For individual buyers, it means notifying the buyer or publishing the notice on the seller's website if it has one. Those steps are not side paperwork. They are part of the correction file itself.
Tax declaration timing also needs separate attention. The correction decision tells you which document to issue. It does not automatically answer when the seller and buyer should reflect the change in VAT reporting. The pre-July 2026 rules placed adjustment and replacement invoices for errors in mandatory content in the tax period of the original invoice, and Circular 91 no longer contains that rule. It fixes a period only for the adjustments in its special cases, such as volume discounts, returned goods and value changes following a competent authority's conclusion: the seller declares those in the period the adjustment invoice is issued, and the buyer in the period it is received. For error corrections, the period follows VAT and tax administration law, so record how you reached your conclusion and how it moved into the tax file. That is where operational evidence, not just the invoice PDF, becomes important.
A defensible correction file usually contains four things: the original invoice reference, the notice or written agreement that supports the correction path, the adjustment or replacement invoice itself, and the downstream accounting record showing how the correction was reflected. If a correction touches amounts, tax, or timing, your ERP and VAT workpapers should tell the same story as the invoice trail.
This is also a good point to remind teams that correction logic is jurisdiction-specific. The mechanics discussed here differ from how VAT credit note corrections work under UK rules and from how Italy handles credit and debit note corrections in e-invoicing, even though all three topics deal with post-issuance invoice fixes. Borrowing the wrong country's pattern is a common source of avoidable compliance mistakes.
Before closing a Vietnam correction file, run a short checklist:
- Confirm whether the error qualified for notice only, adjustment, or replacement, and whether replacement was mandatory for a cash-register or registered-asset invoice.
- Confirm the original invoice reference appears in the notice or correcting invoice, and that a notice-only error reached the tax authority on Form 04/SS-HDDT.
- Confirm the buyer agreement or buyer notice requirement was satisfied for the correct buyer type.
- Confirm same-month batching was used only where the incorrect information was the same, with the invoices listed on Form 01/BK-DCTT.
- Confirm any VAT declaration impact was reflected in the supporting records.
If your team can answer those five points clearly, the correction is much more likely to stand up in accounting review, tax review, and later audit work.