From 2026, along with the abolition of fixed tax, business households will officially switch to a tax management mechanism based on actual revenue and transaction data. The 2025 Law on Tax Administration focuses on transparency and consistency between invoices, declarations and cash flow, instead of the relatively fixed method as before. In that context, the regulations on penalties for administrative violations in the field of tax and invoices are also redesigned in a more detailed and stratified direction.
A noteworthy point is that the fine level does not increase in a "uniform" manner, but is directly linked to the act, the number of violations and the level of impact on tax management data. This approach makes many business households clearly feel greater compliance pressure than the period of applying fixed tax.
Mistakes that easily cause business households to be heavily fined
According to the 2025 Law on Tax Administration, taxpayers are obliged to make full and timely invoices when selling goods and providing services, and at the same time truthfully and accurately declare arising revenue. On that basis, tax and invoice sanctioning decrees continue to apply a penalty mechanism based on the number of violations.
One of the most common errors is not making invoices when a transaction has already occurred. Previously, with small transactions, this error was often less noticed. However, when revenue is compared with cash flow data and electronic invoices, omission of invoices, even if the value is not large, is still considered a violation. The penalty in this case is not fixed, but gradually increases with the number of invoices not made.
In addition, making invoices at the wrong time is also a mistake that many business households easily make, especially in the fields of retail, food, and online business. The habit of collecting transactions at the end of the day or issuing invoices after completing services is no longer suitable for new management requirements. When the number of invoices made at the wrong time is large, the fine can increase rapidly, far exceeding the level that many households previously imagined.
In addition to direct errors related to invoices, business households may also be penalized if they do not store or provide electronic invoices when requested, declare incorrect information or cause large and prolonged differences between declared revenue and actual cash flow.
Cash flow becomes the basis for determining tax risk
The 2025 Law on Tax Administration continues to affirm the rights of management agencies in collecting, exploiting and using information from banks and intermediary payment organizations to serve tax management. However, cash flow through bank accounts is not automatically considered taxable revenue, but is a basis for comparison and verification.
In cases where cash flow shows that transactions have arisen but there are no invoices or corresponding declarations, the management agency has a basis to consider violations of invoices or tax declarations. If the difference only occurs individually, the taxpayer can explain. Conversely, when the difference is repeated many times or has a large value, business households may be classified into a higher risk group, leading to the possibility of being penalized and tax arrears for the undeclared revenue.
The new point of this management mechanism is to clearly distinguish technical errors from systematic violations. The law allows consideration of force majeure, first-time errors or errors due to technical systems, instead of rigidly handling them in the direction of "if there is a difference, punish".
Standardize operations to reduce violation risks for business households
In the context of the new legal framework that has been formed, avoiding risks is not about "avoiding" data, but about proactively standardizing business operations. Issuing invoices at the right time and fully for all arising transactions is a core requirement. Along with that, using a bank account with the correct business registration name, separating personal cash flow and business, helps to make revenue comparison more transparent.
Business households also need to form the habit of periodically monitoring and comparing revenue, even at a simple level. This not only serves tax obligations, but also helps households detect errors early to adjust, instead of letting the difference drag on and become a basis for penalties.
The 2025 Law on Tax Administration clearly shows the orientation: Business households are no longer managed in a "contract - estimate" manner, but are gradually being placed in a compliance environment based on data. Understanding the correct penalty level, understanding risky behaviors and proactively adapting will help business households reduce pressure, avoid heavy penalties and operate stably in the post-contract tax period.
