Hanoi tax department clarifies cases requiring taxpayers to update tax identification numbers

On April 16, 2026, Hanoi’s People’s Committee Chairman Vu Dai Thang chaired a dialogue with small and medium enterprises in the city for 2026. Representatives from Vietnam Post Investment and Construction Consulting Joint Stock Company and My Phuc One Member Co., Ltd. raised concerns related to tax procedures, including personal income tax finalization and invoice requirements.

Personal income tax finalization and tax identification updates

During the dialogue, representatives said that after the personal income tax finalization deadline passes, the tax authority notifies by email that the tax return is not accepted. They asked whether the enterprise would be penalized for late submission in this situation.

Vu Manh Cuong, Head of Hanoi Tax Department, said the issue is particularly important for companies with a large workforce. Under the National Population Data Project (Project 06), from July 1, 2025, the national ID number will be used as the tax identification number. He noted that, under Article 39 of Circular 80/2021/TT-BTC on tax registration, taxpayers must update their tax identification numbers to meet tax obligations.

Cuong said that if the information of dependents or the taxpayer already exists and matches national population data, the tax authority will automatically transfer it. If the data is insufficient or does not match, taxpayers should update their information to ensure the integration of the citizen ID as the tax identification number is correct.

Invoice rules and electronic invoicing for retail sales

The discussion also covered invoice regulations under Decree 70/2025/NĐ-CP and electronic invoicing, including difficulties when retail customers do not request invoices and issues arising during electronic tax declaration.

Cuong cited Article 10 of Decree 123/2020/NĐ-CP, which requires that when providing service invoices, businesses, household businesses, and individual traders record the full name, address, tax code or the unit code linked to the budget, or the buyer’s identification number, with exceptions for certain specific cases. If the buyer does not have a tax code, the invoice does not need to record it.

He added that for supermarket invoices where the buyer is a private individual not engaged in business, the buyer’s name, address, tax code, or digital signature are not mandatory. If the buyer requests, the seller must record the buyer’s tax code or identification number.

For retail sales to private individuals, Cuong said businesses should follow the customer information requirements. For businesses selling directly to consumers, electronic invoices issued from cash-register computers connected directly to the tax authority can be used, which allows full buyer information to be recorded only if requested by the buyer.

Electronic tax declaration system instability

On system instability during tax declaration, Cuong explained that high concurrent traffic—especially around tax finalization—can lead to electronic tax system errors. He said maintenance outages or disruptions during peak periods, as well as user-side limitations, can also contribute.

When errors occur, Cuong advised taxpayers to check their business conditions. If the issue cannot be resolved, taxpayers should contact the tax authority’s online support department for timely assistance. He also recommended retaining screenshots as evidence to justify late payments caused by system problems in order to avoid penalties.

Handling tax arrears due to payment slip errors

In response to a request from Plastic Manufacturing and Trading Joint Stock Company (Duy Tan Hanoi Branch) regarding continuing tax arrears shown on the Public Service Service despite full payment and a late payment notice, Cuong asked the company to review the information on the payment slip.

He said that if an error on the payment slip causes tax arrears and late payment charges, taxpayers should prepare Form No. 01 under Circular 80 of the Ministry of Finance. The form should clearly state the incorrect information, the correct information, and the amount to be adjusted. Once Form No. 01 is prepared and verified, taxpayers will not incur late payment charges from the date of payment into the state budget.

For the company’s case, Cuong said the company had paid into the parent company’s tax code rather than the branch’s tax code, which led to arrears still appearing under the branch’s number. He advised the company to prepare Form No. 01 to coordinate with the tax authority.