What Is Peppol? E-Invoicing Explained Simply

*By Timothy Jacqmin — Co-Founder, Nexuro Digital · July 2026*

TL;DR

• Peppol is a secure international network that lets two accounting systems exchange structured electronic invoices directly, with no email and no PDF. Think of it as the phone network for invoices: whoever your provider is, everyone can reach everyone.
• It runs on a four-corner model: you, your access point, your customer's access point, and your customer. You never handle the technical side; your software does.
• Since 1 January 2026, e-invoicing over Peppol is mandatory between VAT-registered Belgian businesses (B2B). A PDF sent by email and a paper invoice no longer count as valid invoices.
• In practice, a Peppol invoice leaves your software and lands straight in your customer's software: less manual entry, fewer errors, faster payment.
• With Odoo, no third-party tool is needed: Odoo is itself a certified Peppol access point. Registration is free and takes a few clicks.

You have heard the word "Peppol" a dozen times over the past few months. Your accountant mentions it, your software flags it, and since January 2026 it has even become a legal requirement. Yet no one has ever really explained what it actually is.

That is understandable: the word sounds technical, and most explanations are written by and for IT people. At Nexuro, we do the opposite. We explain Peppol the way we would to an SME owner over coffee: plainly, without jargon, focused on what it actually changes for your business.

Here is the guide we wish someone had handed you before the mandate landed.

What is Peppol, exactly?

Let's start with the essentials. Peppol is a secure international network that lets businesses send each other structured business documents (mostly electronic invoices) directly from software to software. The name comes from "Pan-European Public Procurement OnLine," a project first launched for European public procurement and now used far beyond it.

The best analogy is still the telephone. In the past, to call someone you sometimes had to be on the same network. Peppol removes that constraint: no matter which software your customer uses and which one you use, your two systems can communicate. Peppol is therefore less a piece of software than a shared language and a shared directory that make every system compatible.

The network is governed by OpenPeppol, a non-profit international association under Belgian law, founded in 2012. That detail matters: no single private company owns the network. It is run by an organisation where members set the rules together, which keeps the standard open, durable and vendor-neutral.

Key point: a Peppol invoice is not a PDF attached to an email. It is a structured file (data a machine can read on its own) that travels over a dedicated network, straight from one accounting system to another.

How does the Peppol network work (the four-corner model)?

This is the heart of the system, and it is simpler than it sounds. The Peppol network works on a "four-corner model": the sender, the sender's access point, the recipient's access point, and the recipient. You are the first corner, your customer the last. Between them, two technical providers (the access points) carry the invoice.

The key thing to understand: you and your customer never communicate directly. Each of you only talks to your own access point, much as you talk to your own phone operator, not to your correspondent's. Your software sends the invoice to your access point, which validates it, finds the right recipient in the directory, and passes it to your customer's access point, which finally drops it into their software.

Here is the journey of an invoice, corner by corner:

The whole choreography happens in seconds, encrypted and automatic. You never see or manage this machinery: for you, it all comes down to a "send" button in your software.

What is a Peppol access point?

The term is everywhere, so let's make it clear. A Peppol access point is a certified service provider that connects your business to the Peppol network. It is your gateway: it handles security (encryption), the correct format, finding the recipient and delivering the documents. Without one, you can neither send nor receive a Peppol invoice.

In practice, you do not choose "Peppol": you choose an access point. It can be your accounting software if it is certified, or a third-party service. It is exactly like choosing a mobile operator: they all give you access to the same network, but with different plans, pricing and integration.

To move faster, it locates your recipient through a technical directory called the SMP (Service Metadata Publisher). In plain terms: by querying this directory, your access point knows whether your customer is reachable on Peppol and which access point to send the invoice to.

Common mistake: thinking you need to "install Peppol." You don't. You connect to the network through an access point, often already built into your invoicing software. If you run a modern ERP, the feature is probably already there, dormant.

Peppol BIS, Peppol ID: what do these terms mean?

These are the two technical words you will run into most. Good news: they are easy to grasp once translated into plain language.

Peppol BIS (Business Interoperability Specifications) is the standard format of the invoice, meaning the exact way the data must be structured so that every system reads it the same way. The reference version for invoices is called Peppol BIS Billing 3.0. It is based on the European semantic standard EN 16931 and uses a computer language called UBL 2.1. There is nothing for you to do with it: your software produces this format. Just remember it is the required format in Belgium.

The Peppol ID (or participant identifier) is your "phone number" on the network: a unique address that lets others send you invoices. It consists of a scheme code followed by a value. In Belgium, this identifier is based on your enterprise number (BCE/KBO), with the scheme code 0208. A company whose enterprise number is 0308357159, for example, will have the identifier 0208:0308357159.

Why is Peppol becoming mandatory in Belgium in 2026?

This is probably the question that brought you here. Since 1 January 2026, every business established in Belgium and registered for VAT must issue and receive its B2B invoices in structured electronic format, via Peppol. A PDF sent by email and a paper invoice are no longer considered valid electronic invoices between Belgian businesses.

Why the mandate? Officially, for three reasons: to reduce VAT fraud, simplify business administration, and lay the groundwork. As of 1 January 2028, Belgium will introduce a near-real-time reporting system (e-reporting) built on Peppol, replacing the current annual customer listing. So the 2026 mandate is not an end in itself: it is the first building block of a full tax digitalisation.

A few useful calendar markers:

Watch out for one important nuance. Some businesses are exempt from the obligation to issue invoices (non-established VAT entities, bankrupt entities, VAT-exempt activities under Article 44, flat-rate taxpayers until 2028 at the latest), but almost all of them must be able to receive a Peppol invoice. Even if you only invoice private customers (B2C), your suppliers will send you structured invoices. We cover all these cases in our dedicated article on mandatory e-invoicing in Belgium.

What does Peppol actually change for your SME?

Enough theory. Let's look at what changes in your daily life. With Peppol, an invoice leaves your software and lands directly in your customer's software, with no re-keying and no attachment to open. No more PDF that the other side's accountant has to re-enter by hand. The data travels whole, clean, immediately usable.

The table below sums up the shift:

The business benefits are concrete, not theoretical: less time spent on data entry, fewer input errors, clearer tracking, and above all faster payments because the invoice arrives directly in the customer's approval workflow. For an SME, that last point weighs heavily on cash flow. Where it is often sold to you as a "regulatory burden," we mostly see an opportunity to automate a tedious task and make your data more reliable.

Recommendation: don't treat Peppol as a last-minute box to tick. Use it to clean up your invoicing processes and connect your invoicing to your CRM. It is the right moment to run your sales with a CRM you actually use.

How much does Peppol cost, and are there incentives?

The good news first. Registering on the Peppol network is free: what you may pay for is a subscription to an invoicing software that acts as your access point. Many ERPs and accounting tools already include Peppol at no dedicated extra cost. The real cost is therefore not the network, but the tool you choose to use it.

Better still, the Belgian government has introduced a tax incentive. For financial years 2024 to 2027, SMEs and self-employed workers benefit from an enhanced 120% deduction on e-invoicing-related costs (structured-format software subscriptions and advisory fees). In other words, every euro spent to become compliant can be deducted at €1.20. The precise conditions are set out by the tax administration: the e-invoicing cost must, in particular, be shown separately on your supplier's invoice.

Our field reading: the entry cost is low, and the tax incentive lowers it further. The real investment is not financial, it is organisational: taking the time to configure the tool properly and train your team. That is where the difference lies between "we are compliant" and "we genuinely save time."

How do you connect to Peppol with Odoo?

If you use, or are considering, Odoo, the answer is simple. Odoo is itself a certified Peppol access point, so you do not need to go through a third-party tool (like some intermediary services) to send and receive your invoices. Peppol registration is free and available even in the Community edition.

Getting started takes a few clicks: in Odoo, go to Accounting → Configuration → Settings, section "PEPPOL Electronic Invoicing," register, and you can then send and receive customer and vendor invoices directly over the network. The Belgian Peppol BIS Billing 3.0 format is handled natively. In practice, an owner can be operational on Peppol within a single configuration session, provided the Odoo accounting is clean to begin with.

That is where guidance matters. We have been an Official Odoo Partner for four years, and we often see the same thing: technical activation is quick, but it exposes incomplete customer data or badly organised invoicing flows. We break down the setup step by step in our guide on connecting Peppol to Odoo, and we explore other lesser-known Odoo features that save time once invoicing is in place.

Key point: with Odoo, Peppol is not a module to buy, it is a feature already present, waiting to be switched on. The challenge is not to "plug in Peppol," but to cleanly connect invoicing, accounting and CRM so the data flows end to end.

Conclusion: is Peppol a burden or an opportunity?

Peppol is neither a new tax nor yet another piece of software to learn. It is simply the new standard for exchanging invoices between businesses, now mandatory in Belgium, and it makes your invoicing faster, more reliable and better connected to your other tools. The network is free, the tax incentive exists, and if you are on Odoo, the feature is already there.

Our belief is the same as on everything else: a regulatory obligation is also a chance to tidy things up. Clean invoicing, connected to your CRM and your accounting, means reliable data, and reliable data is what lets you steer your business by the numbers rather than by gut feeling.

*Not sure whether your business is correctly connected to Peppol, or whether your invoicing is truly linked to your accounting and your CRM? We can look at it together, simply, during a free audit of your digital ecosystem. No bots, no salespeople: Timothy or Bryan replies to you personally within 24 hours.*

*— Timothy Jacqmin, Co-Founder, Nexuro Digital*

FAQ

What is Peppol in a few words?

Peppol is a secure international network that lets businesses exchange structured electronic invoices directly from software to software, with no email and no PDF. The name comes from "Pan-European Public Procurement OnLine." In practice, it is like a phone network for invoices: no matter your software and your customer's, your two systems can communicate.

Is Peppol mandatory in Belgium?

Yes. Since 1 January 2026, every business established in Belgium and registered for VAT must issue and receive its B2B invoices in structured electronic format via the Peppol network. A PDF sent by email and a paper invoice no longer count as valid invoices between Belgian businesses. A tolerance period on fines runs until the end of March 2026.

What is a Peppol access point?

A Peppol access point is a certified provider that connects your business to the network. It is your gateway: it handles security, format, recipient lookup and invoice delivery. You do not choose "Peppol" directly, you choose an access point, often your invoicing software itself if it is certified, such as Odoo.

How much does Peppol cost for an SME?

Registering on the Peppol network is free. What you may pay for is the subscription to the invoicing software that acts as your access point, and many ERPs include it at no extra cost. On top of that, Belgian SMEs benefit from an enhanced 120% tax deduction on e-invoicing costs for financial years 2024 to 2027. The entry cost is therefore low.

What is the difference between a PDF invoice and a Peppol invoice?

A PDF invoice is an image or document your customer must read, print or re-key by hand. A Peppol invoice is a structured file: it is data the recipient's software understands and integrates automatically into its accounting. A PDF by email is no longer valid in Belgian B2B since 2026; a structured Peppol invoice is.

How do you enable Peppol in Odoo?

Odoo is a certified Peppol access point, with no third-party tool required. In Odoo, go to Accounting, then Configuration, then Settings, and open the PEPPOL Electronic Invoicing section to register for free. You can then send and receive customer and vendor invoices directly over the network, in the natively supported Belgian Peppol BIS Billing 3.0 format.

Sources

• Belgian FPS Finance / official e-invoicing portal — who will be required to use e-invoicing?
• Belgian FPS Finance — tax incentives (enhanced 120% deduction)
• OpenPeppol — About Peppol (governance, four-corner model)
• einvoice.belgium.be — general questions about Peppol (access point, Peppol ID, scheme 0208)
• Odoo documentation — electronic invoicing in Belgium (Peppol)

Need to switch to e-invoicing? Discover our offer: Peppol and Odoo.