Peppol and e-invoicing: what it is and how to prepare

Many business owners picture an electronic invoice as a PDF attached to an email. Understandable, but formally that's not an e-invoice at all. A genuine e-invoice is a file containing structured data: every piece of information — invoice number, amounts, VAT, supplier — sits in a fixed field that software can read directly.

The difference shows up on the receiving end. A PDF has to be retyped or interpreted by a person (or an OCR scanner), with plenty of room for error. An e-invoice is read automatically into the recipient's accounting software: no retyping, no misreads, no attachments that go missing.

In short:

• paper or PDF: manual work on the receiving end, error-prone and slow
• e-invoice (like UBL): machine-readable, processed automatically, straight into the books

Two terms come up again and again in e-invoicing, and they do different jobs.

UBL (Universal Business Language) is the file format: an XML standard that captures all invoice data in a structured way. Virtually every modern accounting package can read UBL invoices.

Peppol is the network the invoices travel over securely. Think of it as a kind of international postal system for business documents: your software hands the invoice off to a certified access point, and the network guarantees encrypted delivery to the recipient's access point. Every participant can be found through a unique Peppol address, usually based on their Chamber of Commerce (KVK) or VAT number.

The big advantage: you don't need separate arrangements per customer. As long as the recipient is connected to Peppol, your invoice gets through — regardless of which software package they use. For more background, check the network organization itself at peppol.org.

Across Europe, e-invoicing is shifting from optional to standard, though the pace varies by country.

• Belgium is making B2B e-invoicing mandatory from 2026. If you sell to Belgian business customers, this affects you directly and soon.
• The EU is working on the ViDA package (VAT in the Digital Age), which introduces digital VAT reporting based on e-invoices for cross-border trade. Rollout happens in stages over the coming years.
• The Netherlands has no mandatory date for B2B e-invoicing. Suppliers to the national government already invoice electronically, and e-invoicing is expected to become steadily more common here too.

The realistic takeaway: there's no deadline in the Netherlands to panic over, but the direction is clear. If you can already send and receive e-invoices, you won't need to scramble later. For official regulatory updates, keep an eye on the Belastingdienst (Dutch Tax Administration).

Even without a mandate, e-invoicing brings immediate benefits, especially if you have business customers or suppliers:

• faster payment: your invoice lands straight in your customer's system, skipping the steps that otherwise cost days
• fewer errors: no retyping means no mistyped amounts or mixed-up invoice numbers
• less back-and-forth: delivery via Peppol is traceable, so "we never received your invoice" becomes a thing of the past
• more efficient purchasing: if you receive UBL invoices from your own suppliers, your costs get read in automatically instead of booked by hand

For webshops growing toward business customers, international buyers, or larger retail partners, e-invoicing is also increasingly a requirement rather than a nice-to-have.

Preparing for e-invoicing doesn't have to be a big project. This is enough to get you ready:

1. Check your invoicing software. Can it generate UBL invoices and send them via Peppol? If not, add this to your checklist for your next software choice.
2. Get your master data in order. An e-invoice lives or dies by correct data: KVK number, VAT number, IBAN, and address details for both you and your business customers.
3. Map out your business relationships. Ask your biggest customers and suppliers whether they're already connected to Peppol — there's a good chance you can already exchange e-invoices with them today.
4. Choose a connection. You don't need your own technical setup: an access point is often already built into your invoicing software.

slimzaak, for instance, has this built in by default: you send UBL e-invoices via Peppol from the same environment where your marketplace and webshop invoices are created, so you're ready for Europe's e-invoicing requirements without adding extra systems.