Peppol vs PDF by Email: Why the Structured Format Changes Everything

The Most Common Misconception About Electronic Invoicing

When discussing electronic invoicing in Luxembourg, one confusion consistently arises: many businesses think that sending a PDF by email constitutes an electronic invoice within the meaning of the law. It does not.

A PDF sent by email is certainly a digital document, but it is not a structured electronic invoice as defined by the European EN 16931 standard. This distinction is fundamental, as it has direct implications for legal compliance, operational efficiency and the security of commercial exchanges.

This article compares the two approaches in detail and explains why Peppol represents a leap forward compared to PDF by email.

PDF by Email: The Limitations of a False Simplicity

PDF by email may seem simple and practical at first glance. However, this method has many limitations:

No Automatic Processing

A PDF is primarily a visual document, designed to be read by a human. It does not contain structured data directly usable by your accounting software. Each invoice received in PDF must be entered manually or scanned by OCR software (optical character recognition), with all the error risks that entails.

No Delivery Guarantee

Sending an email does not guarantee that it has been received and read by the recipient. Emails can get lost in spam, be ignored or deleted by mistake. There is no reliable integrated delivery confirmation.

Security Risks

Email is a channel vulnerable to phishing attacks and invoice fraud. Cybercriminals can intercept or spoof emails to send fake invoices with modified bank details. This type of fraud costs European businesses millions of euros each year.

Non-Compliant for B2G

Since March 2023, public bodies in the Grand Duchy no longer accept PDF invoices by email. Only Peppol and MyGuichet.lu channels are authorised. Sending a PDF by email to a public administration will result in invoice rejection.

Peppol: The Structured Format That Changes Everything

Unlike PDF, a Peppol invoice is a structured document in XML (UBL 2.1 format), where each piece of information occupies a dedicated and standardised field. Here is what this changes concretely:

100% Automatic Processing

Data from a Peppol invoice can be read and processed automatically by any compatible accounting tool. No more manual entry or OCR recognition. The net amount, VAT, product references, bank details: everything is structured and instantly usable. Peppol Box offers CSV, XML and PDF exports as well as an API available for automation. Additionally, thanks to Flexina Sync, your accountant automatically retrieves your invoices from Peppol Box — free of charge and with no effort on your part.

Guaranteed and Traceable Delivery

The Peppol network provides delivery confirmations for each send. You know with certainty whether your invoice has been delivered to the recipient. In case of a technical problem, the system alerts you immediately.

Enhanced Security

The Peppol network is a closed and certified network. Each participant is authenticated and identified by their VAT number. It is impossible for an unauthorised third party to send an invoice impersonating another business. This eliminates invoice fraud risk.

Full Legal Compliance

Peppol invoices are compliant with the EN 16931 standard and are accepted by all public administrations. They also meet the ACD's fiscal documentation requirements.

Point-by-Point Comparison

• Format: PDF is an unstructured visual document; Peppol uses structured XML (UBL 2.1)
• Processing: PDF requires manual entry or OCR; Peppol allows 100% automatic processing
• Delivery: Email without guarantee; Peppol with delivery confirmation
• Security: Email vulnerable to phishing; Peppol is a certified and secure network
• B2G compliance: PDF not accepted; Peppol is an official channel
• Processing cost: PDF involves hidden entry costs; Peppol drastically reduces costs
• Errors: PDF subject to human entry errors; Peppol eliminates errors through structured format
• Archiving: PDF requires manual filing; Peppol allows automatic and structured archiving

The Numbers Speak for Themselves

European studies show significant differences in processing costs:

• Average cost to process a paper or PDF invoice: 10 to 30 euros
• Average cost to process a structured electronic invoice: 1 to 3 euros

For a business processing 100 invoices per month, the difference can represent savings of 1,000 to 2,700 euros per month, or 12,000 to 32,000 euros per year.

The Transition Is Simpler Than You Think

Moving from PDF by email to Peppol does not require completely overhauling your processes. With a solution like Peppol Box, the transition is smooth:

1. Sign up for Peppol Box in a few minutes
2. Register your VAT number as a Peppol identifier
3. Start sending structured invoices via the web interface or mobile app
4. Receive invoices from your suppliers directly in your Peppol inbox

You can continue to send PDF invoices by email to clients not yet connected to Peppol, while using Peppol for those who are. The transition can be gradual.