Peppol E-Invoicing in Denmark: What Freelancers and Small Businesses Actually Need to Do in 2026

You send a PDF invoice to a Danish municipality. A week later it comes back: "Rejected. Please send as an e-invoice." If you've never heard of Peppol, OIOUBL or NemHandel, this is how most freelancers and small businesses find out they exist.

What Is Peppol, in Plain English?

Peppol (Pan-European Public Procurement On-Line) is an open standard and network that lets businesses exchange invoices, orders and other documents as machine-readable data. Instead of a PDF that someone has to read and retype, the customer's accounting system receives structured data it can process automatically.

Three terms come up constantly in Denmark:

• Peppol BIS Billing 3.0: the common European invoice format used on the Peppol network. It is based on the EU standard for electronic invoices (EN 16931).
• OIOUBL: the Danish national UBL-based invoice format, long used with public-sector customers. Version 2.1 is the one in everyday use.
• NemHandel: the Danish infrastructure for exchanging electronic business documents, which works on top of the Peppol standards.

Is E-Invoicing Mandatory in Denmark in 2026?

It depends on who your customer is:

Two developments make it worth preparing now. First, Denmark's bookkeeping act (bogføringsloven) pushes businesses toward digital bookkeeping systems, which makes structured invoice data far easier to handle. Second, the EU's ViDA (VAT in the Digital Age) package introduces mandatory e-invoicing for cross-border B2B transactions between EU member states, with the main obligations phased in by 2030. Rules and dates evolve, so always confirm current requirements with the Danish Business Authority (Erhvervsstyrelsen) or the Danish Tax Agency (Skattestyrelsen).

Why Small Businesses Should Care Anyway

• You get paid faster. Structured invoices flow straight into the customer's accounts-payable system, with no manual re-keying and fewer "we never received it" delays.
• You win bigger customers. Public bodies and larger companies often will not onboard a supplier who can't send e-invoices.
• You make fewer mistakes. E-invoice formats validate mandatory fields, so a missing VAT number or wrong total is caught before it reaches the customer.
• You are ready for what's next. When cross-border e-invoicing becomes mandatory, your workflow is already in place.

What a Valid E-Invoice Must Contain

An e-invoice carries the same legal content as any Danish invoice, in structured form. At a minimum:

• Seller name, address and CVR number
• Buyer name and address (and CVR, EAN or GLN where relevant)
• A unique, sequential invoice number
• Issue date, delivery or service date, and payment due date
• Description, quantity and unit price for each line
• VAT rate and amount per rate, and the total including VAT
• Payment details (bank account, IBAN, payment reference)

Public-sector invoices usually also need a buyer reference or order number and the customer's EAN/GLN location number, which tells the network exactly where to deliver the invoice. Ask the customer for it before you invoice.

How to Issue a Peppol or OIOUBL Invoice with Fakturify

1. Create the invoice as usual. Enter the customer's CVR number and Fakturify fills in the company details automatically.
2. Add the lines and VAT. Set the quantities, prices and VAT rate. Fakturify calculates the totals.
3. Add the buyer reference or EAN/GLN if the customer is a public body or asks for it.
4. Export the e-invoice file. Download the invoice as Peppol BIS Billing 3.0 or OIOUBL 2.1 XML, ready for the customer or your Peppol access point.
5. Send and track. Email the invoice or share a payment link, then follow its status from the dashboard.

Fakturify is free to start, works in English, Danish and Estonian, and is built for freelancers, makers and small teams who want compliant invoices without learning accounting software. Create your first invoice in a few minutes. No credit card required.

Common Mistakes That Get E-Invoices Rejected

• Missing or wrong EAN/GLN. The invoice has no address on the network and never arrives.
• No buyer reference. Public customers often reject invoices without an order or reference number.
• VAT totals that don't add up. Rounding differences between line totals and the invoice total fail validation.
• Sending a PDF when XML was required. A PDF attached to an email is not an e-invoice for a public body.
• Reusing or skipping invoice numbers. Numbers must be unique and sequential.

Frequently Asked Questions (FAQ)

What is Peppol?
Peppol is an international standard and network for exchanging business documents such as invoices as structured, machine-readable data instead of PDFs.

Do I have to send e-invoices in Denmark?
Yes, if your customer is a Danish public authority. For private B2B and B2C customers it is not currently required by law, although some large customers ask for it.

What is the difference between OIOUBL and Peppol BIS 3.0?
OIOUBL is the Danish national invoice format, while Peppol BIS Billing 3.0 is the European format used across the Peppol network. Both are UBL-based XML. Danish public customers accept either, so use whichever the customer specifies.

What is an EAN or GLN number?
It is a 13-digit location number that identifies where an e-invoice should be delivered, typically a department of a public authority. You need it to address invoices to public-sector customers.

Can a freelancer or sole proprietor send e-invoices?
Yes. Any business with a CVR number can issue e-invoices. You don't need a large accounting system, only software that produces valid Peppol BIS 3.0 or OIOUBL files.

Is a PDF invoice still valid?
For most private customers, yes, as long as it contains all legally required information. For public-sector customers, a structured e-invoice is required.

Does Fakturify support Peppol and OIOUBL?
Yes. Fakturify can export invoices as Peppol BIS Billing 3.0 and OIOUBL 2.1 XML, alongside standard PDF invoices.

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This article is general information, not legal or tax advice. Requirements change, so verify current rules with Erhvervsstyrelsen or Skattestyrelsen. Fakturify supports invoicing in Denmark with CVR lookup, Danish VAT, and Peppol BIS 3.0 and OIOUBL 2.1 export. Available in English, Danish and Estonian.