How does an e-invoice work?
The difference between an e-invoice and an emailed PDF is in who reads the invoice. With a PDF, a person reads the amounts and retypes them or has a recognition program guess them. With an e-invoice, the invoice number, the date, the lines, the rates and the amounts are in fixed fields, and your customer’s bookkeeping can process them directly. That saves not only time but also the errors that retyping creates.
UBL is the language in which those fields are written; NLCIUS is the Dutch implementation that says which fields are mandatory and how they are used. In practice you supply both forms: the data file for your customer’s software, and a legible rendering for the person who wants to look at it anyway. That double form is not a luxury but follows from the requirement that the invoice must stay legible for as long as you must keep it.
Sending is a separate step. Peppol is a network on which parties can deliver each other’s e-invoices, and it requires a connection. Being able to make an invoice in UBL and being able to send it through Peppol are therefore two different things. Only the first is needed to invoice electronically with a customer who simply accepts the file from you.
Where is an e-invoice in the law?
These legal sources come from the specialist dossiers that were reviewed on 24 August 2026. Mind the difference that becomes large in a dispute: a statutory article next to a value is where that value is found, not a justification for how it applies to your situation.
- Article 35b of the Dutch VAT Act (Wet OB 1968)requires that the authenticity of the origin, the integrity of the content and the legibility of the invoice are guaranteed from issue to the end of the retention period
The links go to the statutory text on wetten.overheid.nl, in the version that applied on 24 September 2026.
What does basestep do with an e-invoice?
Every invoice you finalise comes out in two forms: a PDF to read and a UBL file to read in, with the NLCIUS basis underneath. Both are also in your exit bundle, so you keep them if you stop. What is not there is sending through Peppol; that is deliberately on the list of things the platform does not do.
All calculations, explanations and signals in basestep are calculation support and instruction, not tax or legal advice. Amounts are estimates based on your own input; the Dutch tax authority (Belastingdienst) sets the assessment.
Where does it go wrong with an e-invoice?
The two mistakes you run into most often in practice with this term, and what they cost you.
Calling a PDF an e-invoice
An emailed PDF is a digital invoice and not an electronic one in the intended sense. If a customer asks for an e-invoice, they mean the data file, and mixing up the two costs you a rejected submission.
Keeping only the data file
Legibility must stay guaranteed until the end of your retention period. A file you can no longer show in seven years without the right software does not automatically meet that.
Confusing making and sending
Being able to create an invoice in UBL says nothing about a Peppol connection. Anyone who wins a tender where Peppol is mandatory does not have enough with the file alone.
Further reading
Three places this term is tied to, inside this glossary and beyond.