Peppol Validator

Peppol diagrams

Original SVG diagrams of the Peppol four-corner and five-corner models, the document flow and the validation pipeline. Themed for light and dark mode, scalable to any size, and free to embed on your own site with an attribution link back to this page.

By Peppol Validator · Last updated

Why these diagrams

When you start working with Peppol you have to internalise a handful of architectural concepts: how the four-corner model routes a document, what changes when a fifth corner (the tax authority) is added, what happens to an invoice between "send" and "booked", and how a validator actually checks a UBL file. Most explanations of these come with low-resolution screenshots from a slide deck or a paid stock illustration.

These diagrams are clean, original SVGs. Each one is themable: it inherits its colour from the surrounding text, so it works in light mode, dark mode and any custom palette. Each one carries its own copyright and attribution metadata so it stays attributed even if it is hotlinked, screenshotted or pasted into another document.

Use them in your documentation, your blog post, your slide deck, or your internal wiki. The only request is that you keep the "Diagram by Peppol Validator" link visible somewhere near the image.

The four diagrams

Peppol four-corner model

How a Peppol invoice flows from seller to buyer through two Access Points, with the SML and SMP discovery layer underneath.

Peppol four-corner modelDiagram showing how a Peppol document flows. Corner 1 (Seller) sends the invoice to Corner 2 (Sender Access Point). The Sender Access Point looks up the recipient via SML and SMP discovery, then transmits the document over AS4 to Corner 3 (Receiver Access Point). Corner 3 delivers the document to Corner 4 (Buyer). Source: https://peppolvalidator.com/diagrams/four-corner-modelPeppol four-corner modelPeppol Validator (peppolvalidator.com)© Peppol Validator. Free to embed with attribution link to peppolvalidator.com.https://peppolvalidator.com/diagrams/four-corner-modelPeppol networkCORNER 1SellerERP / accounting systemCORNER 4BuyerERP / accounting systemCORNER 2Sender Access Pointvalidates, signs, looks up recipientCORNER 3Receiver Access Pointdecrypts, validates, forwardsUBL invoiceAS4 over HTTPSsigned & encryptedUBL invoiceSML & SMP discoveryfinds the recipient endpointand certificate© peppolvalidator.com
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Peppol five-corner model

The four-corner model extended with a fifth corner for the tax authority. Used for near real-time e-reporting (Belgium 2028, EU ViDA).

Peppol five-corner modelDiagram showing the Peppol five-corner model. Corner 1 (Seller) sends an invoice to Corner 2 (Sender Access Point), which transmits it over AS4 to Corner 3 (Receiver Access Point), which delivers it to Corner 4 (Buyer). At the same time, the Access Points report a copy or summary of the invoice to Corner 5, the Tax Authority, for near real-time e-reporting (used by Belgium from 2028 and by the EU VAT in the Digital Age reform). Source: https://peppolvalidator.com/diagrams/five-corner-modelPeppol five-corner modelPeppol Validator (peppolvalidator.com)© Peppol Validator. Free to embed with attribution link to peppolvalidator.com.https://peppolvalidator.com/diagrams/five-corner-modelPeppol networkCORNER 5Tax Authoritynear real-time e-reportingCORNER 1SellerERP / accounting systemCORNER 4BuyerERP / accounting systemCORNER 2Sender Access Pointvalidates, signs, reportsCORNER 3Receiver Access Pointdecrypts, validates, reportsUBL invoiceAS4 over HTTPSsigned & encryptedUBL invoicereportreportSML & SMP discoveryfinds the recipient endpointand certificate© peppolvalidator.com
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Peppol document flow

End-to-end lifecycle of a Peppol invoice: create, package, sign, transmit over AS4, validate, deliver, MLR, Application Response.

Peppol document flowLifecycle diagram of a Peppol invoice. The seller creates the invoice in their ERP, the sender Access Point packages it as UBL and signs it, transmits it over AS4 to the receiver Access Point, which validates the schematron rules and forwards it to the buyer's ERP. A Message Level Response acknowledges delivery and an optional Application Response (Invoice Response) communicates the buyer's processing status. Source: https://peppolvalidator.com/diagrams/document-flowPeppol document flowPeppol Validator (peppolvalidator.com)© Peppol Validator. Free to embed with attribution link to peppolvalidator.com.https://peppolvalidator.com/diagrams/document-flowSELLER ERPSENDER APRECEIVER APBUYER ERP1. Create invoiceERP / accounting2. Package UBLBIS Billing 3.03. Validate & signschematron + AS4 cert4. SML / SMP lookupfind recipient endpointAS45. Receive AS4decrypt + verify cert6. ValidateEN16931 + Peppol BISMLR7. Deliver to ERPbook invoice8. Invoice Responseaccept / reject (optional)Application Response (Invoice Response) returns through both Access Points© peppolvalidator.com
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Peppol validation pipeline

How the Peppol Validator processes a UBL or CII invoice: format detection, CEN EN16931 schematron, Peppol BIS schematron, SVRL parse and merge.

Peppol validation pipelineDiagram of the Peppol Validator pipeline. The XML invoice is parsed, the format is detected (UBL or CII), and the document is run through the pre-compiled CEN EN16931 schematron (SEF) and the Peppol BIS Billing 3.0 schematron (SEF) using SaxonJS XSLT 2.0. The SVRL outputs are parsed and merged into a single result with errors, warnings and infos. Source: https://peppolvalidator.com/diagrams/validation-pipelinePeppol validation pipelinePeppol Validator (peppolvalidator.com)© Peppol Validator. Free to embed with attribution link to peppolvalidator.com.https://peppolvalidator.com/diagrams/validation-pipelineValidation pipelineSTEP 1Upload XMLUBL or CII invoiceSTEP 2Detect formatUBL ↔ CrossIndustryInvoiceUBLCIISTEP 3CEN EN16931 SEFSaxonJS XSLT 2.0STEP 4Peppol BIS 3.0 SEFSaxonJS XSLT 2.0CII path: only CEN EN16931 (CII) is run.STEP 5Parse SVRL & merge issueserrors · warnings · infosSTEP 6Resultvalid · invalid · error© peppolvalidator.com
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Licensing & attribution

The diagrams on this page are © Peppol Validator. You can embed them, modify the colours through CSS, or include them in articles, slide decks and documentation, on the condition that you keep a visible link back to peppolvalidator.com near the image. Each SVG also carries a Dublin Core copyright block so the attribution travels with the file when downloaded.

Validate your Peppol invoices

Drop a UBL or CII XML invoice and check it against every EN 16931 and Peppol BIS Billing 3.0 rule. Free, instant, no signup.

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