With tax authorities intensifying their management of e-commerce activities, especially revenue generated on e-commerce platforms, the question "What happens if I sell online without issuing invoices?" is no longer a theoretical concern but has become a real legal risk for many businesses.

This article clarifies the invoicing obligations of online sellers, the applicable legal basis, the time when invoices must be issued, and the legal consequences of non-compliance.

Is it mandatory to issue invoices when selling online?

The answer is: Yes.

According to the Tax Administration Law and the system of guiding documents on invoices, all sales of goods and provision of services that generate revenue must be invoiced , regardless of:

• Selling online or offline?
• Selling on e-commerce platforms or selling through social media.
• Did the customer request an invoice?

The fact that "customers do not request an invoice" does not give rise to the right to be exempt from issuing an invoice .

For businesses selling goods on e-commerce platforms, this obligation is even more tightly controlled because order data, revenue, and cash flow are stored and provided to tax authorities by the platforms as required by law.

Read more: Do revenues from e-commerce platforms need to be declared for tax purposes?

The legal basis currently applicable to online sellers.

Two key legal documents that online sellers need to be aware of:

• Decree 123/2020/ND-CP : Regulations on the general legal framework for invoices and supporting documents.
• Decree 70/2025/ND-CP (amended and supplemented) : Clarifies the responsibility for issuing electronic invoices in e-commerce activities, especially the mechanism for connecting data with tax authorities.

From July 1st, 2025 , issuing electronic invoices for business households selling goods on e-commerce platforms will no longer be a recommended phase , but will become a mandatory requirement , monitored through data reconciliation between the platform, shipping companies, banks, and tax authorities.

This means:

• If an order is successfully placed but there is no corresponding invoice , the business owner risks being asked to provide an explanation and having their tax assessed .

When should invoices be issued when selling online?

One common misconception is that invoices only need to be issued after payment has been received. This understanding is legally incorrect.

According to current regulations, the time of invoice issuance is the time of transfer of ownership or the right to use the goods , regardless of whether payment has been received or not.

For online sales, this time period is usually understood as:

• The order has been successfully delivered to the customer.
• Cash on delivery (COD) or prepayment does not change the obligation to issue an invoice.

Some cash register models with data connectivity are allowed to issue consolidated invoices for the day, but must ensure the following:

• 100% of the revenue generated is recognized.
• Do not carry over to the next period.

Delivering goods first and invoicing later, or issuing invoices on a backdated date, are all considered incorrect invoicing practices.

Read more: Everything about electronic invoices: When to issue them, how to handle errors

Will I be penalized for not issuing invoices when selling online?

What are the penalties for not issuing invoices when selling online?

Yes, and the penalties are now much harsher than before.

According to the new penalty regulations, the failure to issue invoices when selling goods can lead to:

• Administrative penalties for invoice-related violations.
• Taxes will be collected on all actual revenue generated.
• Calculate late payment penalties for taxes that are subject to retroactive collection.

Besides risks from tax authorities, sellers also face risks from the e-commerce platform itself. In many cases, seller accounts can be locked or restricted if they are found to have violated tax obligations.

Read more: Common legal risks when doing business online

What are the procedures for handling cases where invoices are issued incorrectly?

From June 1st, 2025 , any errors on electronic invoices will no longer be processed by cancellation .

Depending on the nature of the error, the seller must choose one of two options :

• Adjustment invoice : Used when a part of the content needs to be adjusted (price, tax, quantity, etc.).
• Replacement invoice : Applicable when it is necessary to replace an entire incorrectly issued invoice.

Choosing the wrong processing method can render invoices invalid and directly affect tax declarations.

Read more: Overview of replacement invoices and adjustment invoices

Practical solutions for online sellers.

In the context of increasingly transparent sales data, the safest approach is not to "avoid invoices," but to standardize the process from the outset.

Online businesses should:

• Use a management system capable of automatically generating electronic invoices upon order completion.
• Synchronize order , inventory, revenue, and invoice data to avoid discrepancies.
• There are established procedures for handling returns, refunds, and invoice adjustments.

In practice, many businesses are choosing integrated management platforms like GTG CRM , which allow them to:

• Automatically generate electronic invoices through MISA and S-Invoice.
• Automatically generate replacement invoices when returns or exchanges occur.
• Integrate and synchronize products from e-commerce platforms.
• Manage products, inventory, stock levels, suppliers, orders, shipping, invoices, and accounting data all on one system.

This method helps reduce the risk of manual errors and meets the requirements for verification and reconciliation when needed.

GTG CRM automatically generates electronic invoices and synchronizes products from e-commerce platforms.

Conclude

Selling goods online without issuing invoices is no longer a "minor issue" in today's world.

Sellers need to understand:

• Having revenue means having the obligation to issue invoices.
• Not issuing invoices does not reduce the tax payable, but only increases the risk of being subject to back taxes and penalties.
• Standardizing processes from the outset is the only way to achieve sustainable business.

With the abolition of flat-rate taxes and the shift of household businesses to declaring based on actual revenue , electronic invoices are not only an obligation but also a tool to protect sellers from future legal risks.