Peppol BIS Billing 3.0: a guide for UK businesses

Peppol BIS Billing 3.0 is the specification that sets out what an invoice or credit note must look like when it is sent over Peppol. It takes the European e-invoicing standard EN 16931, narrows it with Peppol's own rules (it is a CIUS), and is normally written in UBL 2.1 XML. If you send e-invoices to the NHS or to customers on Peppol today, this is almost certainly the format your software produces.

The identifiers that mark a BIS Billing 3.0 invoice

Every BIS Billing 3.0 invoice carries two header values:

<cbc:CustomizationID>urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0</cbc:CustomizationID>
<cbc:ProfileID>urn:fdc:peppol.eu:2017:poacc:billing:01:1.0</cbc:ProfileID>

Rule PEPPOL-EN16931-R004 checks the CustomizationID: it must start with that value and must not carry a syntax version suffix such as ::2.1. Since release 3.0.21, an optional second profile, urn:peppol:bis:billing_with_response, signals that the buyer will always send an Invoice Response.

Versions and releases

BIS Billing 3.0 is updated regularly; recent releases came in November 2025 and May 2026. Each release has a publication date and a later "mandatory to use from" date:

Release	Published	Mandatory from	Notable for UK users
3.0.20	24 Nov 2025	23 Feb 2026	Removed text saying attaching a PDF copy of the invoice was not compliant
3.0.20-hotfix	27 Jan 2026	23 Feb 2026	New EAS/ICD code for Slovakia
3.0.21	20 May 2026	17 Aug 2026	New optional "billing with response" profile; rule R004 tightened

Your provider should keep up with releases. Ask which version it validates against.

What a UK invoice must contain

EN 16931 sets the core content (invoice number, dates, seller and buyer, lines, totals and VAT breakdown). BIS Billing 3.0 adds rules on top. The ones UK senders most often miss:

Requirement	Rule	UK tip
Buyer reference or purchase order reference	PEPPOL-EN16931-R003 (fatal)	Many UK buyers do not give a reference. Agree one (for example a PO or cost centre) or use the order number. See buyer reference BT-10.
Seller electronic address	PEPPOL-EN16931-R020 (fatal)	Your Peppol ID, for example schemeID="9932" GB123456789 (made up)
Buyer electronic address	PEPPOL-EN16931-R010 (fatal)	The customer's Peppol ID, exactly as registered
Valid EAS scheme	PEPPOL-EN16931-CL008 (fatal)	Use 9932, 0088 and so on, never a made-up "GB" or "VAT"
VAT identifier prefix	BR-CO-09 (fatal)	GB123456789 (or XI… for NI goods trade with the EU)
GLN check digit	PEPPOL-COMMON-R040 (fatal)	Validate GLNs (0088) before use
Only one document-level note	PEPPOL-EN16931-R002 (fatal)	Merge free-text notes
No empty elements	PEPPOL-EN16931-R008 (fatal)	Common with in-house XML exports
Totals add up	EN 16931 BR-CO rules	See BR-CO-15

A failure on any fatal rule means the invoice is rejected. You will receive a negative Message Level Status from the buyer's provider, or your own provider will block the invoice before sending.

VAT in BIS Billing 3.0

Each line and each VAT breakdown carries a VAT category code and a rate. For UK use the main ones are S (standard rate, with the percentage, for example 20), Z (zero rated), E (exempt, with an exemption reason), AE (reverse charge, for example construction services) and O (outside scope). How UK-specific situations such as the domestic reverse charge should be coded is covered in UK VAT category codes in Peppol.

Currency is any ISO 4217 code. GBP invoices are routine. If the invoice is in another currency, the VAT total in GBP (the VAT accounting currency) can be given too, subject to rules R005 and R054. See Multi-currency e-invoices.

Minimal skeleton (illustrative)

<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2" ...>
  <cbc:CustomizationID>urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0</cbc:CustomizationID>
  <cbc:ProfileID>urn:fdc:peppol.eu:2017:poacc:billing:01:1.0</cbc:ProfileID>
  <cbc:ID>INV-1001</cbc:ID>
  <cbc:IssueDate>2026-10-20</cbc:IssueDate>
  <cbc:InvoiceTypeCode>380</cbc:InvoiceTypeCode>
  <cbc:DocumentCurrencyCode>GBP</cbc:DocumentCurrencyCode>
  <cbc:BuyerReference>PO-4711</cbc:BuyerReference>
  <cac:AccountingSupplierParty><cac:Party>
    <cbc:EndpointID schemeID="9932">GB123456789</cbc:EndpointID>
    ...
  </cac:Party></cac:AccountingSupplierParty>
  ...
</Invoice>

For a full worked file, see UK Peppol invoice XML example.

Is there anything UK-specific in it today?

No. Appendix C of the BIS lists national rules "provided by each country's Peppol Authority", applied by the seller's country. Rules exist for Germany, Denmark, Greece, Iceland, Italy, the Netherlands, Norway and Sweden. There are none for the UK. The EAS code list contains 9932 (UK VAT number), but there is no UK validation of it.

What is confirmed and what is not

CONFIRMED:

• Peppol will be the core interoperability network for UK e-invoicing (GOV.UK, 23 June 2026).
• The mandate covers B2B and B2G VAT invoices from April 2029.
• Bodies covered by the Public Procurement Act 2023 must already accept e-invoices that comply with BS EN 16931, as the government's November 2025 consultation response notes.

NOT YET CONFIRMED (as of 20 October 2026):

• Whether BIS Billing 3.0 will be the UK format, or whether a UK CIUS or extra UK rules will apply
• Whether UBL only, or CII as well, will be accepted (see UBL vs CII)
• UK rules on identifiers, VAT codes for UK-specific schemes, self-billing and attachments

The implementation roadmap is due at Budget 2026 on 28 October.

What to do now

1. Ask your software provider whether it produces BIS Billing 3.0 invoices and credit notes, and which release it validates against.
2. Run a few real invoices through your provider's validator and fix any fatal errors.
3. Clean your customer master data. Peppol IDs, VAT numbers and buyer references are the usual problems. See Master data clean-up.
4. Track the roadmap. If a UK CIUS appears, it is likely to build on EN 16931, so work done now on BIS Billing 3.0 should carry over.