What is e-invoicing and how does it work?

E-invoicing will be mandatory for all B2B transactions in Belgium starting January 1, 2026. This means a significant change for companies that still work with PDF invoices via email or even paper invoices. In this comprehensive guide, we explain what e-invoicing entails, how it works, and how you can prepare your business for this new obligation.

What is e-invoicing?

E-invoicing, also known as electronic invoicing, is the process by which invoices are created, sent, received, and processed in a structured digital format. This goes far beyond simply sending a PDF invoice via email.

An e-invoice is an invoice that:

• Is formatted in a standardized XML format

• Contains structured code that can be processed automatically

• Is exchanged via a secure network (such as, but not limited to, Peppol)

• Fully digital flows from sender to receiver

The significant difference with traditional invoicing is that e-invoices are machine-readable. This means that the receiving party can automatically read the invoice data with their program, without manual entry. Cashfeed is such a tool that translates everything into plain language.

Difference between e-invoice and PDF invoice

Although both are digital, there is a world of difference between a traditional PDF invoice and a real e-invoice:

PDF invoice via email:

• Static document that cannot be processed automatically

• Requires manual entry by the receiver

• No standardized structure

• Prone to errors during manual processing

• No automatic validation

  
  

E-invoice (XML format):

• Structured data that can be processed automatically

• Direct integration with systems such as Cashfeed and accounting systems

• Standardized format according to international standards

• Automatic validation of data

• Faster processing and fewer errors

How does e-invoicing work?

Process from creation to processing

The e-invoicing process occurs in several steps:

1. Creation The invoice is created in an invoicing program that supports e-invoices. Cashfeed is such a program known for creating e-invoices in no time. The system then converts the invoice data to the correct XML format according to the legally required standards.

2. Sending The e-invoice is sent to the receiver via a secure network (in Belgium, this is Peppol). The tool, also known as Access Point Provider, ensures the technical connection to the network.

3. Receipt The receiver receives the e-invoice through their own Access Point. The system automatically validates whether the invoice is correctly formatted and meets all requirements.

4. Processing The received e-invoice can be automatically read into the receiver's accounting system, where further processing and approval takes place.

File formats and standards (UBL, Peppol-BIS)

E-invoices use standardized formats to ensure interoperability:

UBL (Universal Business Language): An international standard for electronic business documents. UBL defines the XML structure for various documents, including invoices.

Peppol-BIS (Business Interoperability Specifications): Specific implementation guidelines that determine how UBL is used within the Peppol network. These ensure that all participants speak the same "language".

These standards contain rules for:

• Mandatory and optional fields

• Data formats (dates, amounts, codes)

• Validation rules

• Code lists (VAT rates, currencies, etc.)

Validation and interoperability

A crucial aspect of e-invoicing is automatic validation. Every e-invoice is checked for:

• Syntactical correctness (correct XML structure)

• Semantic correctness (logical consistency of data)

• Business rules (for example, VAT calculations)

This validation occurs both at sending and receiving, ensuring high quality of exchanged data.

Role of Cashfeed

Cashfeed plays an important role as an e-invoicing tool by:

• Peppol Access Point: Facilitating access to the Peppol network

• Conversion: Converting invoices in all formats (Excel, PDF, etc.) to XML

• OCR technology: Automatic text recognition for incoming PDF invoices

• Workflow support: Forwarding invoices for approval and control

• Integration: Connections with all popular accounting packages

Customers of Cashfeed report a time savings of 5-10 times across the entire invoicing process, with fewer errors and faster payments.

Legal framework for e-invoicing in Belgium

From January 1, 2026, e-invoicing will be mandatory for all B2B transactions between Belgian companies that are VAT liable. The penalties for non-compliance are substantial:

• €1,500 for the first finding

• €3,000 for the second finding

• €5,000 from the third finding

For a comprehensive explanation of the legal obligations, exceptions, and transitional measures, we recommend reading our detailed post on the legal framework.

Peppol and e-invoicing

Peppol, short for Pan-European Public Procurement OnLine, is the international network over which e-invoices can be exchanged. It acts as a kind of "WhatsApp for invoices" - a secure network where businesses and governments can exchange electronic documents.

For more information about Peppol, we refer you to our more extensive post "What is Peppol actually?".

Steps to start with e-invoicing

1. Inventory of current invoicing process

Determine your needs based on your current working method.

• What invoicing program(s) are you using today?

• How many invoices do you send and receive per month?

• Who is involved in the invoicing process? In other words, will you also need to collaborate with others in this new environment, and in what way?

• What integrations exist with other systems?

• What are the bottlenecks in the current process?

Sometimes you simply cannot do without your Excel formulas or special features from your current invoicing program.

2. Choice of software or e-invoicing provider

Your existing invoicing program may also support Peppol. Find out how it will do so.

Digitally receiving all your invoices in a standardized format is a huge opportunity. This way, everything can be immediately read and prepared for approval or payment, you get real-time insights (bye-bye Excel sheets), and AI can help you process recurring invoices faster.

So choose wisely, as the right functionalities can save you a lot of time.

Pay attention to factors such as ease of use, integration options, costs (but also consider the 120% deductibility), additional services (OCR, workflow, etc.), support, and scalability.

3. Testing and validation

Start on time. With the mandatory deadline of January 1, 2026, it's better to start scouting tools now. Most tools offer you a few weeks of free use before they become paid. This time should enable you to test multiple tools for validation for free.

Also, know that you can only have one Peppol Access Point for receiving your Peppol invoices. Your "mailbox" can only be in one place. You can send invoices from multiple systems, although it becomes a bit more complex to apply consistent invoice numbering.

4. Review internal workflow

E-invoicing may require adjustments in your internal processes:

• Approval procedures for incoming e-invoices

• New control and validation steps

• Backup procedures for technical problems

• Maintaining electronic documents

5. Training personnel and communication

Ensure adequate training for your team. Cashfeed, for example, is extremely intuitive but offers a range of help pages and a live chat.

The benefits of e-invoicing

• Faster payments & receipts

E-invoices arrive directly in the receiver's system, without intermediaries. This eliminates delays caused by mail delivery, email issues, or manual processing.

On average, e-invoices are paid several days faster than traditional invoices.

• Less chance of errors

Automation significantly reduces human errors. Cashfeed connects with Bizzy to always use the most up-to-date business data on invoices.

The likelihood of typos during manual entry for incoming invoices also drops significantly. Both in Cashfeed and in your banking app.

Moreover, there is also a much lower risk of incorrect bookings, and you can count on a consistent application of VAT rules.

Simplification of accounting

E-invoicing streamlines the entire accounting process: automatic import into accounting packages, faster matching of payments, structured archiving, and better and more real-time reporting and analysis.

Integration with existing systems

Accounting package and ERP connections

Cashfeed will automatically forward your invoices to your accounting package, in pdf or xml format.

APIs and data mapping

For custom integrations, APIs are used:

• RESTful APIs for real-time exchange

• Webhook notifications for status updates

• Data mapping for field conversions

• Error handling and retry mechanisms

Automation of matching and reconciliation

Advanced e-invoicing solutions offer:

• Automatic matching of invoices with orders

• Reconciliation of payments

• Deviation management

• Approval workflows

Frequently Asked Questions (FAQ)

What is the difference between e-invoice and PDF via email?

The biggest difference lies in the processability. A PDF is a static document that must be processed manually, while an e-invoice contains structured data that can be automatically read by computer systems. E-invoices use XML formats that are machine-readable, allowing for automatic and error-free processing, validation, and integration.

Is a PDF via email an e-invoice?

No, a PDF invoice sent via email is not an e-invoice in the sense of the legislation. For mandatory e-invoicing from 2026, the invoice must be exchanged in XML format via a structured network such as Peppol. PDFs are not structured enough for automatic processing.

What costs are associated with e-invoicing?

Costs vary depending on your choice, somewhere between free and €15 per month for basic use. Often, part of that subscription price is variable depending on the number of invoices you process. Setup and support are usually free or already included in this price.

Good news: E-invoicing software is currently 120% deductible for sole proprietorships, liberal professions, and small companies.