Adjusting invoices and deducting input VAT are two tasks that any accountant must master, because even a small mistake can directly affect a business's tax rights. During operation, many businesses face unexpected situations such as defective goods during production requiring compensation to customers, or having to send out free samples for commercial purposes or product introductions.
This is why mastering regulations on invoice adjustments and input VAT deductions has become a mandatory requirement for any accountant, especially given the significant changes to the legal framework since mid-2025. Decree 70/2025/ND-CP (amendment and supplementation of Decree 123/2020/ND-CP) and Decree 181/2025/ND-CP The detailed guidance on the Value Added Tax Law No. 48/2024/QH15 has set out clearer principles but also tightened the conditions for application. A small error in adjusting invoices and deducting input VAT can lead to businesses having their expenses disallowed, being subject to tax arrears, or being penalized for late payment. This article will systematize the current regulations and analyze two common real-world scenarios to provide accountants with a basis for accurate application.
What does invoice adjustment and input VAT deduction mean?
Essentially, these are two closely related operations that serve two different purposes in accounting and taxation:
- Adjust the invoice.This involves the seller creating a new invoice to modify the information (quantity, unit price, tax rate, amount, etc.) on a previously issued invoice, instead of canceling the original invoice as per the old regulations. According to Decree 70/2025/ND-CP, businesses can choose between two forms of creating a new invoice. adjustment invoice or establish replacement invoice, depending on the nature of the defect and the agreement with the buyer.
- Input VAT deduction: This is the right of businesses to deduct the VAT paid when purchasing goods and services from the VAT payable, provided they fully meet the requirements for invoices and documents as stipulated in the VAT Law and its guiding documents.
If input invoices contain errors requiring adjustment, or if the invoices do not meet the payment documentation requirements, the corresponding right to deduct input VAT will be directly affected. Therefore, correctly understanding and implementing the correct procedures from the invoice adjustment and input VAT deduction stage is a prerequisite for businesses to avoid risks during tax settlement.
Legal basis for adjusting invoices and deducting input VAT.
The current legal framework governing these two operations includes:
- Decree 123/2020/ND-CP Regulations regarding invoices, supporting documents, and foundational texts have now been amended and supplemented.
- Decree 70/2025/ND-CPEffective from June 1, 2025, this Decree amends and supplements several articles of Decree 123/2020/ND-CP, in which Clause 13 of Article 1 directly regulates the issuance of adjustment invoices and replacement invoices.
- Law on Value Added Tax No. 48/2024/QH15, which stipulates the general principles regarding the conditions for deducting input VAT.
- Decree 181/2025/ND-CPEffective from July 1, 2025, the regulations detailing the implementation of the Value Added Tax Law include Articles 25, 26, and Clause 9 of Article 28, which are directly related to the conditions for deducting input VAT.
One important change to note: Electronic invoices that have been assigned a code or whose data has been submitted to the tax authorities cannot be arbitrarily canceled. Instead, they must be processed through adjustment or replacement in accordance with the legally prescribed procedures. This is the foundation for better understanding how to handle practical situations regarding invoice adjustments and input VAT deductions, as outlined below.
Adjusting invoices when compensating for goods with quality defects.
This is a fairly common situation in manufacturing and trade, where goods are defective or do not meet quality standards during the production process, forcing the selling company to compensate the customer.
When does a selling company need to issue an adjustment or replacement invoice?
In this case, according to the provisions of Clause 13, Article 1 of Decree 70/2025/ND-CP (amending and supplementing Decree 123/2020/ND-CP), the selling company can choose one of two forms of handling:
- Issue an adjustment invoice for a previously issued invoice, or;
- Issue a replacement invoice for the previously issued invoice.
After selecting the appropriate method, the company submits a supplementary declaration in accordance with current legal regulations. The option to choose between adjustment and replacement allows accountants greater flexibility in handling transactions, depending on the nature of the compensation and the extent of discrepancies compared to the original invoice.
Regulations regarding the content displayed on amended and replaced electronic invoices.
To ensure transparency and a basis for comparison with the original invoice, the law clearly stipulates the mandatory information that must be included on electronic adjustment invoices and replacement electronic invoices:
- Electronic invoice adjustment: It must have text "Adjustment for Invoice Form No.… Symbol… Number… Date… Month… Year".
- Electronic invoices as a replacement: It must have text "Replacement for Invoice Form No.… Symbol… Number… Date… Month… Year".
Note: Without this phrase, the adjusted or replacement invoice may be considered invalid during tax audits, directly affecting invoice adjustments and input VAT deductions for both the buyer and seller.
Free sample delivery and conditions for input VAT deduction.
The second common situation in practice is when businesses send out free samples for the purpose of product introduction, marketing, or market expansion. However, the conditions for deducting input VAT on goods used as samples vary depending on whether the samples are consumed domestically or exported abroad.
Free sample delivery within the country.
For cases of exporting sample goods domestically free of charge, if the company complies with all applicable trade laws and regulations, and the input costs of these goods fully meet the conditions for deduction under Articles 25 and 26 of Decree 181/2025/ND-CP, then the company is entitled to deduct the corresponding input VAT.
In other words, the prerequisites here consist of two parallel elements:
- Sample export activities must comply with trade laws and regulations (not fall under prohibited or restricted cases);
- Goods used as samples must have complete and valid tax payment invoices and documents (Article 25) and meet the conditions for non-cash payment documents (Article 26) as with normal purchase transactions.
If both of the above conditions are met, the adjustment of invoices and the deduction of input VAT for domestic sample goods can be carried out normally like other purchase and sale transactions.
Exporting free samples abroad.
The second case is more complicated: the company exports samples abroad without charging any money, but... No non-cash payment receipt (Because it is not a cash transaction, no cash flow is generated through the bank.)
According to Clause 9, Article 28 of Decree No. 181/2025/ND-CP, in this case, the company:
- Not deductible input value-added tax corresponding to the sample exported goods; and
- Output value-added tax is not applicable. for that sample export product.
This is a fundamental difference compared to the case of exporting samples domestically, and it is an accounting point to remember to avoid confusing the two situations when making invoice adjustments and deducting input VAT related to samples.
In addition, for businesses that do not have an in-house accounting department or want to optimize operational resources, outsource accounting services This is also a worthwhile option to consider, especially when businesses frequently generate invoice and VAT transactions and need assistance reviewing documents before tax settlement.
A quick comparison of two cases of sending free samples.
To easily understand the difference in handling invoice adjustments and input VAT deductions for free samples, you can quickly compare the two cases using the following table:
| Criteria | Domestic samples | Export samples |
| Legal basis | Articles 25 and 26 of Decree 181/2025/ND-CP | Clause 9, Article 28 of Decree 181/2025/ND-CP |
| Prerequisites | Comply with commercial law and qualify for input tax deductions. | No non-cash payment receipts |
| Input VAT deduction | Deductible if eligible | Not deductible |
| Calculate output VAT. | According to standard procedure | No need to calculate |
The comparison table above clearly shows that, even for free samples, the "domestic" or "export" factor, along with the presence or absence of payment documentation, will completely determine the outcome of invoice adjustments and input VAT deductions.
Common accounting risks when adjusting invoices and deducting input VAT.
Based on the two scenarios analyzed above and during the process of providing consulting support to businesses, MAN has compiled and summarized some common risks that accountants and businesses need to avoid:
- Incorrect supplementary declaration period: Declare the adjusted or replacement invoice in the current period instead of the period in which the original invoice being adjusted or replaced was issued.
- The required text is missing: The information regarding "Adjustment for invoice…" or "Replacement for invoice…" is not fully displayed according to the format, symbol, number, and date of the original invoice.
- Ignore the condition regarding non-cash payment documents: Input VAT deductions are not permitted without fully verifying the conditions in Article 26 of Decree 181/2025/ND-CP, especially for transactions of 5 million VND or more.
- Confusion between domestic and export samples: Incorrect application of legal grounds can lead to improper deduction of input VAT, potentially resulting in retroactive collection during tax settlement.
If a business wants to better control its accounting and tax operations, and minimize errors in invoice declaration and processing, it can refer to the following: full accounting service From specialized and experienced units like MAN – Master Accountant Network, you can receive support from document recording and accounting to report preparation and fulfilling related tax obligations.
Conclude
It is clear that adjusting invoices and deducting input VAT is not simply a business operation, but requires accountants to closely adhere to specific legal grounds, from Clause 13, Article 1 of Decree 70/2025/ND-CP on the form, content, and declaration period of adjusted and replacement invoices, to Articles 25, 26, and Clause 9, Article 28 of Decree 181/2025/ND-CP on the conditions for deducting input VAT in each specific situation.
In the context of continuously updated legal frameworks regarding invoices, receipts, and VAT, businesses should establish rigorous internal control procedures and regularly review emerging situations to ensure that invoice adjustments and input VAT deductions always comply with current regulations. This is especially important for businesses that need to focus resources on core operations while still ensuring tax compliance. full package tax accounting services This is a suitable solution to support the management and execution of tax-related tasks.
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Responsible for production and professional content review by: Mr. Le Hoang Tuyen – Founder & CEO of MAN – Master Accountant NetworkHe is a CPA Vietnam auditor with over 30 years of in-depth experience in accounting, auditing, taxation, and corporate legal consulting.
Frequently Asked Questions about Invoice Adjustments and Input VAT Deductions
In which period should adjustment invoices and replacement invoices be declared as supplementary declarations?
According to current regulations, adjustment invoices and replacement invoices are declared in the period in which the adjusted or replaced invoice is issued, which is the period of the original invoice, not the current period in which the adjustment or replacement invoice is issued.
Can input VAT be deducted if goods are sold as samples free of charge?
It depends on the case. If it's a sample for domestic consumption, complies with commercial law, and meets the conditions in Articles 25 and 26 of Decree 181/2025/ND-CP, then it's deductible. If it's a sample exported abroad without non-cash payment documentation, according to Clause 9, Article 28 of Decree 181/2025/ND-CP, the enterprise is not allowed to deduct input VAT, nor is it required to calculate output VAT.
What should be done if there is no non-cash payment documentation when exporting samples?
According to Clause 9, Article 28 of Decree 181/2025/ND-CP, in this case, the company is not allowed to deduct the corresponding input VAT, but conversely, it is also not required to calculate output VAT for the exported sample goods.
When compensating for goods with quality defects, is the company required to issue an adjusted invoice, or can it choose another method?
According to Clause 13, Article 1 of Decree 70/2025/ND-CP, companies have the right to choose to issue an adjustment invoice or a replacement invoice for a previously issued invoice, depending on the actual situation, and then file a supplementary declaration in accordance with regulations.
Can an incorrectly issued invoice still be canceled and a new one issued, as was previously the case?
No. Decree 70/2025/ND-CP has abolished the regulation on canceling incorrectly issued invoices as stipulated in Decree 123/2020/ND-CP. Instead, electronic invoices that have been assigned a code or whose data has been submitted to the tax authority must be processed by adjustment or replacement; they cannot be arbitrarily canceled.
