Adjustment vs. replacement invoice in Vietnam: What's the difference?

When a business discovers an error in an issued electronic VAT invoice in Vietnam, it generally needs to consider two correction methods: issuing an adjustment invoice or issuing a replacement invoice.

Both methods are used to correct previously issued invoices, but they work differently and produce different invoice records.

So, what is the difference between an adjustment and a replacement invoice? When should you use each method? And what should businesses know before correcting an invoice?

TL;DR

• Adjustment invoice: Records the difference or information being corrected compared with the original invoice.
• Replacement invoice: Issues a new invoice containing the complete corrected information to replace the incorrect one.
• Which should you use? It depends on the error, invoice type and applicable regulations. Not every situation allows a free choice.
• With Invoi: Simply enter the corrected information as you would when creating a new invoice. Invoi automatically calculates the necessary differences.

1. What is an adjustment invoice?

An adjustment invoice is an electronic invoice issued to correct information or amounts on a previously issued invoice.

Instead of recreating the entire invoice, the seller issues a new document showing the changes relative to the original invoice.

For example:

A business issues an invoice with the following details:

• Quantity: 10 products
• Unit price: VND 500,000
• Subtotal: VND 5,000,000
• VAT: 10%

After reviewing the transaction, the business discovers that the correct quantity should have been 12 products.

If the business chooses an adjustment invoice, it records the difference of 2 additional products, representing an increase of VND 1,000,000 before VAT and VND 100,000 in VAT.

The adjustment invoice must clearly reference the original invoice and identify the adjustment being made.

Under the current regulations, value adjustments must reflect the actual difference: increases are recorded as positive amounts, while decreases are recorded as negative amounts.

2. What is a replacement invoice?

A replacement invoice is a new electronic invoice issued to replace a previously issued invoice containing errors.

Unlike an adjustment invoice, which records the changes, a replacement invoice contains the complete corrected invoice information.

For example:

A business issues an invoice with the following details:

• Quantity: 10 products
• Unit price: VND 500,000
• Subtotal: VND 5,000,000
• VAT: 10%

The business later discovers that the correct quantity should have been 12 products.

If it chooses to issue a replacement invoice, it creates a new invoice containing the complete corrected information:

• Quantity: 12 products
• Unit price: VND 500,000
• Subtotal: VND 6,000,000
• VAT: 10%

The new invoice must clearly state that it replaces the original invoice.

3. Adjustment vs. replacement invoice: key differences

Both methods correct errors in issued electronic invoices, but they differ in how the corrected information is recorded.

Criteria	Adjustment invoice	Replacement invoice
Purpose	Corrects information or amounts on the original invoice	Replaces the original invoice with a new one
Content	Shows the changes being made	Contains the complete corrected information
Amounts	Records the increase or decrease	Records the amounts on the new invoice
Reference	Identifies the original invoice	Identifies the invoice being replaced
Result	Adds a correction to the original invoice record	Creates a new invoice to replace the incorrect one

The most important distinction is:

• Adjustment: Records the difference between the original and corrected information.
• Replacement: Reissues the invoice with the complete corrected information.

4. When should you adjust an invoice, and when should you replace it?

Under Article 10 of Circular 91/2026/TT-BTC, for certain errors involving the buyer's tax identification number, product descriptions, invoice amounts, VAT rates, VAT amounts or other mandatory information, the seller may choose to issue an adjustment or replacement invoice.

However, this does not mean that every situation allows a free choice between the two methods. Certain invoice types and specific transactions have their own requirements.

When should you use an adjustment invoice?

An adjustment invoice is generally suitable when a business needs to record the difference between the original information and the corrected information.

Examples include:

• Increasing or decreasing product quantities.
• Correcting unit prices.
• Adjusting taxable amounts.
• Adjusting VAT rates or VAT amounts.
• Correcting other information covered by the applicable adjustment rules.

When an amount needs to increase or decrease, the adjustment invoice records the difference directly, making it possible to compare the correction with the original invoice.

When should you use a replacement invoice?

A replacement invoice is suitable when the business needs to reissue the invoice with complete corrected information.

Examples include:

• An invoice contains multiple errors that need to be corrected.
• The business wants to issue a new invoice containing all the correct information.
• The transaction falls under a category where replacement is specifically required.

Some invoice categories, including certain invoices generated by cash registers, have specific correction requirements. Businesses should therefore check the invoice type and transaction before choosing a correction method.

5. Important rules when adjusting or replacing invoices

Regardless of which method is used, businesses must follow the applicable requirements.

The original invoice must be referenced

An adjustment invoice must clearly state which invoice it adjusts. A replacement invoice must also identify the invoice it replaces.

A written agreement may be required

When the buyer is an economic organisation, another organisation, a household business or an individual business, the seller and buyer generally need to prepare a written agreement identifying the error before proceeding. Certain exceptions apply.

Subsequent corrections must follow the original method

If an invoice was initially corrected through an adjustment or replacement, and another error is discovered later, subsequent corrections must use the same method as the first correction.

Increases and decreases must reflect the actual difference

For value adjustments, increases must be recorded as positive amounts and decreases as negative amounts.

6. Adjusting and replacing invoices is easier with invoi.vn

One of the most challenging parts of issuing an adjustment invoice is calculating the difference between the original invoice and the corrected information.

With a replacement invoice, the person preparing it must enter and verify the complete corrected information while ensuring that the new invoice is properly linked to the original.

Invoi is designed to simplify both processes.

Instead of manually calculating the differences, simply enter the corrected invoice information as you would when creating a new invoice.

Invoi automatically handles the necessary calculations and prepares the corresponding adjustment or replacement invoice.

You do not have to calculate every increase or decrease or work through the calculations manually.

This saves time for both business owners and accountants, reduces the risk of errors and makes invoice corrections more straightforward.

Discover invoi.vn to manage business invoices and collaborate with your accountant in one place.

Conclusion

Adjustment and replacement invoices are both used to correct previously issued electronic invoices in Vietnam, but they record corrections differently.

An adjustment invoice shows the changes relative to the original invoice, while a replacement invoice contains the complete corrected information in a new invoice.

The appropriate method depends on the invoice type, the nature of the error and the applicable regulations.

With Invoi, you do not need to spend time calculating the differences manually. Simply enter the corrected information as you would when creating a new invoice, and let Invoi take care of the calculations behind the scenes.