What is a real e-invoice? Differences between PDF and structured XML

In our previous blog, we explained what is changing from 2027 regarding electronic invoicing. Now, let’s look at the absolute basics: 👉 What exactly is an electronic invoice and why is the PDF format ceasing to be a "real" invoice?

📄 PDF vs. Electronic Invoice: A Fundamental Difference

Currently, most companies operate as follows:

• issue an invoice in their system
• save it in PDF format
• send it via email

This closes the process. However, the problem is that a PDF is a document designed for humans, not for information systems. In practice, this means:

• data must be manually re-entered
• there is a higher risk of errors
• processing is slower and less efficient

⚙️ So, What is an Electronic Invoice?

An electronic invoice (e-invoice) is a structured data file (e.g., in XML format). Unlike a PDF:

• data is stored in a precisely defined structure
• the system clearly identifies individual items (price, VAT, supplier, etc.)
• no manual data entry is required

💡 Simply put: system → system (without the need for human intervention)

🔍 What Does It Look Like in Practice?

Today (PDF)

• The company issues an invoice
• It sends it in PDF format via email or as a printed document by mail
• The other party processes it manually

From 2027 (e-invoice)

• The company issues an invoice in the system
• The invoice is sent as an XML through its own access point (an electronic "postman") to the other company's access point
• The other company's system processes it automatically

👉 No re-keying, no errors, no delays

⚠️ Why Won't PDF Be Enough?

From 2027, Act No. 222/2024 Coll. on Value Added Tax, as amended, clearly states: PDF will not be considered an electronic invoice. It may still exist, but:

• only as a "preview" intended for humans
• not as an official accounting document

In practice, this means that:

• PDF will stop meeting legal requirements
• it will not be suitable for automated processing
• it will not suffice for fulfilling obligations toward the state

🧾 What Must an E-invoice Contain?

An electronic invoice contains the same data as today, but in a precisely defined structure:

• supplier and customer
• invoice number
• dates
• individual items
• prices and VAT
• total amount

The difference lies in the fact that the data is processed as structured data, not just displayed as text.

🔗 Why is This Important?

This approach enables:

• automated accounting
• more effective oversight by the state
• interconnection of individual systems
• minimization of errors

And above all: a significant acceleration of the entire financial process within the company.

💡 Where Do Companies Most Often Struggle?

The biggest misconception is often: "It's enough to generate an XML and we're done." In practice, however, the entire process needs to be addressed:

• the correct format in accordance with the relevant standard
• delivery of the invoice via the correct communication channel
• data verification (validation)
• receiving invoices from business partners
• integration with the internal ERP system

And it is in these areas where complexity most often arises.

🚀 How to Solve This Without Complications?

If you don't want to handle technical details internally, it makes sense to use a ready-made solution. Systems from Asseco are designed exactly for this purpose – they cover the entire electronic invoicing process:

• creating an e-invoice in the correct XML format
• verifying its accuracy (validation)
• ensuring delivery via the correct infrastructure
• receiving invoices from business partners
• integration with an ERP or accounting system

👉 For the company, this means only one thing: it doesn't have to deal with legislative or technological aspects – the system ensures everything works correctly and in compliance with requirements.

👉 What's Next?

Now you know what an e-invoice is and why the PDF format is insufficient. In the next part, we will explain:
👉 How electronic invoicing works in practice – what PEPPOL is and what role the so-called digital "postman" plays

If you want to avoid chaos right before 2027, it pays to start today – ideally with a solution that has electronic invoicing prepared from the ground up.