Receiving an invoice through Peppol doesn't mean you have to accept it automatically. Even though e-invoicing is mandatory between companies based in Belgium, it's still important to dispute errors or incorrect amounts quickly and correctly. Business owners and investors should keep the golden rule in mind: dispute invoices on time, in writing, and in a verifiable way. 

Since January 2026, e-invoicing between Belgian companies has been carried out through the Peppol network. However, this doesn't change an important legal principle: anyone who disagrees with an invoice they've received must dispute it in a timely and clear manner. Otherwise, the invoice may be considered accepted, which could create an obligation to pay it. 

A technical status is not a legal objection 

Today's accounting software makes it easy to process invoices digitally. For example, you can mark an invoice as rejected, on hold, or pending. However, that technical status in your software is not automatically equivalent to a legally valid objection. 

Peppol is, first and foremost, a secure network through which invoices are exchanged directly between systems. The network itself doesn't offer any mechanism for legally disputing an invoice. As a result, an internal status doesn't guarantee that your supplier is aware of your specific objections. 

So, if you want to dispute an invoice effectively, you must make sure your objection actually reaches the supplier. 

Dispute in writing and clearly 

An invoice dispute must be made in writing, either by email or, if the situation requires it, by certified mail. A well-reasoned email may be enough, but it's important to be able to prove later that the supplier received it. In addition, the dispute should clearly identify the invoice in question (at a minimum, the invoice number and date). Below are some reasons that may justify disputing an invoice: 

• work or services that were not performed; 

• incorrect quantities; 

• a price that doesn't match the agreed-upon terms; 

• goods or services delivered incomplete or defective; 

• a duplicate or unjustified invoice. 

The more specific the justification, the stronger your position with the supplier. Likewise, whenever possible, relevant documentation should be attached, such as a purchase order, quote, contract, or proof of delivery. 

Meeting deadlines 

In a B2B context, a reasonable timeframe applies, which depends on the specific circumstances. As a practical guideline, periods of 7 to 14 days are often cited, although in some cases a period of up to one month may be justified. That's why the safest approach is to act as soon as an error is detected. 

The process may also include reviewing the general terms and conditions and any underlying agreement. These may set out specific deadlines or formalities for disputing invoices, and such provisions can be very important for a company based in Belgium. 

Documentation and proof of receipt 

Ideally, the paying company should be able to prove that its objection actually reached the supplier. For this reason, when sending an email, it's advisable to request a delivery receipt or read receipt through the Peppol network. A reply from the supplier acknowledging the claim is, of course, also very useful. 

If, on the other hand, you choose to send a certified letter, be sure to keep the proof of mailing and tracking information. 

Finally, at this stage it's also a good idea to keep records of all follow-up correspondence. If the supplier responds to the claim, it's important to stay on top of the follow-up. That correspondence could prove decisive if a legal dispute ultimately arises. 

Set clear agreements with your accountant 

A good internal invoice management workflow is at least as important as the legal dispute itself. The best way to save time is to avoid having invoices processed automatically without anyone checking that their content is correct. 

International expansion in Belgium 

Belgium, the world's 22nd-largest economy and home to the main institutions of the European Union, offers an environment of constant opportunities for investment in Belgium. Through Fidelium by Auxadi, we have strengthened our presence in the country to support companies starting operations there with their financial, accounting, and tax management, and to make their CFOs' work easier from day one. 

Are you planning your expansion into Belgium? Talk to our experts and find out how we can help.

About Auxadi

With 26 subsidiaries across Europe, the United States, and Latin America, Auxadi is today the leading Spanish accounting firm serving multinational companies and real estate investment funds. Through its technology-driven approach and strong client-focused culture, Auxadi acts as an extension of its clients' finance departments worldwide, providing accounting, tax, payroll, transfer pricing, and corporate legal services.

Its proprietary MySPV technology platform, more than 300 employees, and over 1,700 clients have positioned Auxadi as a benchmark in the tech-enabled services sector, not only in Spain but internationally.

Auxadi can become your ideal partner. We offer a one stop shop value added outsourcing services in the areas of accounting and reporting, tax compliance, payroll management and representation services, among others.