What is the difference between a PDF and an electronic invoice?

Since the introduction of the general e-invoicing obligation on January 1, 2026, confusion has reigned at the breakfast tables of many entrepreneurs. After all, you’ve been sending your invoices by email as PDFs for years. Wasn't that "electronic"?

Unfortunately, the answer is: no. At least, not according to the definition used by the tax authorities and the Peppol network. Now that the legislation is in force, it is crucial to understand the difference between a "digital invoice" (PDF) and a "structured e-invoice" (XML).

In this blog, we explain why the PDF has lost its official status in B2B traffic and how to handle those unreadable files that are now entering your accounting system.

The fundamental difference: Image vs. Data

The core of the confusion lies in the definition.

• A PDF is actually nothing more than a digital photo of a sheet of paper. Humans can read this, but computers cannot. An accounting program sees an image, not numbers.

• An e-invoice (XML/UBL) is a file full of structured computer language (code). It contains tags like <InvoiceLine> and <TaxTotal>. This is unreadable to you, but your software and your client's software can automatically import and process this file without typing errors.

Can I still invoice by email?

For transactions falling under the new B2B obligation: no. Emailing PDFs (even with a QR code on them) is no longer sufficient. Email is unstructured and insecure. The legislation now requires data to be sent structurally (as XML) via a secure network like Peppol.

Belgium follows a dual-track approach:

• The Standard (Peppol): The government promotes the Peppol network as the standard. It is secure, automated, and supported by most software packages.

• Mutual Agreement: The law allows alternatives. If both parties (supplier and client) agree, structured files (like XML) may be exchanged via another method, as long as they meet European semantic standards.

In short, sending a PDF by email is no longer valid as the main invoice. While sending a 'smart' UBL is legally allowed, provided your client agrees and it complies with the EN16931 standard, practice shows that Peppol is the easiest solution for most businesses."

New rules for your archive

Now that you are receiving XML files instead of PDFs, everyone is asking: "What do I need to keep?"

The XML is the original

Previously, the paper invoice or the PDF was the proof. From now on, the XML file is the only legally valid source for the tax authorities.

Can I still print my invoices?

You are certainly allowed to print an e-invoice or convert it to a readable PDF for internal use (or to show to your manager). But beware: this print version is not the legal proof. The tax authorities only look at the digital XML.

How long must I keep e-invoices?

The rules for retention remain unchanged, whether paper or digital.

• B2B invoices: 10 years.

• B2G (Government) invoices: 7 years. You must ensure that the files remain authentic, integral, and readable throughout this entire period.

Key benefits of e-invoicing vs traditional invoicing

It sounds like a lot of hassle, but now that everyone has been forced to switch, the benefits are becoming visible. It’s not just about "complying" with the legislator:

• Money in your account faster: E-invoicing shortens the so-called 'Days Sales Outstanding' (DSO). Because the invoice appears directly in the customer's software package, it is approved and paid faster.

• Fewer errors: No more retyping means no errors in bank account numbers or amounts.

• Less administration: The process of sending, receiving, and booking happens largely automatically.

Pro tip: Be careful with credit notes

Now that everything is automated, terminology matters. A common mistake in accounting packages is the use of "negative invoices." In the Peppol network (and according to Belgian VAT rules), a "negative invoice" effectively doesn't exist. If you need to correct something, you must create a Credit Note (UBL CreditNote). This is a specific document type that refers to the original invoice.

Banqup makes the code readable

You don't have to be a programmer to work with XML files. A tool like Banqup works like a translator:

• You create the invoice as you always do (visually).

• Banqup converts this in the background into the mandatory XML code.

• We send it via Peppol to your customer.

• Your customer receives the data directly in their accounting system, and receives a readable PDF as an attachment for the human eye.

This way, you comply with the law without having to dive into the code yourself.

Discover Banqup