Peppol knowledge base
Understand the network behind every Peppox integration
Search practical guidance covering standards, identifiers, discovery, transport, validation, operations and country models.
BAS
Basics
High-level overview of Peppol, governance, and core concepts.
What is Peppol and who operates it?
Peppol is a governed, interoperable framework and network for exchanging structured business documents (e.g., e-invoices, credit notes, MLR). It is coordinated by OpenPeppol, a non-profit association that defines specifications and certifies Access Points and SMPs.
What benefits does Peppol provide over point-to-point integrations?
Peppol uses a “connect once, reach many” model via certified Access Points, reducing bespoke interfaces, enforcing shared validation rules (EN 16931, BIS/PINT), improving cross-border interoperability, and enabling standardized discovery and secure transport.
Is Peppol mandatory across the EU?
There is no single EU-wide Peppol mandate. The EU requires EN 16931 for public procurement e-invoices; many countries introduce national B2B obligations. Peppol is widely adopted as the way to comply and interoperate.
What documents are most common on Peppol?
Invoice and CreditNote (BIS Billing 3.0 / PINT), Message Level Response (MLR), and Invoice Response. Logistics documents also exist in the Peppol Post-Award set.
What is the “four-corner model”?
Sender → Sending Access Point → Receiving Access Point → Receiver. Discovery (SML→SMP) is used to find the receiver’s capabilities and secure endpoint prior to delivery.
IDE
Identifiers (ISO 6523)
Understanding participant identifiers and common pitfalls.
How are recipients identified?
Peppol uses ISO 6523 schemes (ICD + value), formatted as iso6523-actorid-upis::ICD:VALUE (e.g., GLN = 0088, Belgian CBE = 0208).
Which identifier scheme should I use?
Use the scheme that matches your official identifier (e.g., GLN 0088, Belgium 0208 for BCE/CBE). Your Access Point or national authority guidance should confirm the correct scheme.
Common mistakes with identifiers
Mixing up VAT and company-register IDs; dropping leading zeros; using a country VAT format under the wrong ICD; using test identifiers in production.
Directory vs registration
Being visible in a directory or lookup tool is not the same as having a valid SMP record for a specific document/process. Always verify the receiver’s SMP capabilities.
DIS
Discovery (SMP/SML)
How SML and SMP work together.
What is the difference between SML and SMP?
SML (Service Metadata Locator) maps a participant ID to its SMP. The SMP (Service Metadata Publisher) stores the participant’s supported document types, process IDs, and endpoints.
What should I check in an SMP record?
Correct documentTypeID, processID, active endpoint with peppol-transport-as4-v2_0, and a valid certificate. Confirm the environment (test vs production).
Why do lookups sometimes fail with 404 or 429?
404 = no capability published for that participant/document in that SMP. 429 = rate-limiting by public endpoints; throttle or use your provider’s API.
DOC
Documents & Profiles
BIS Billing 3.0, PINT, and related profiles.
What is Peppol BIS Billing 3.0?
A CIUS of EN 16931 that defines how to exchange UBL Invoice and Credit Note on Peppol with additional rules and code lists to ensure interoperability.
What is PINT and when is it used?
The Peppol International Invoice Model (PINT) harmonizes e-invoicing globally and underpins country specializations (e.g., PINT A-NZ, PINT MY, SG BIS).
What are ProcessIDs and why do they matter?
ProcessIDs (e.g., cenbii-procid-ubl::urn:fdc:peppol.eu:2017:poacc:billing:3:1.0) express business processes linked to a document profile; they must match the receiver’s SMP entry.
MLR vs Invoice Response
MLR provides technical/business-level feedback; Invoice Response provides business acknowledgements (e.g., accept/reject with reasons). Check SMP support.
VAL
Validation & Code Lists
Making EN 16931 + BIS/PINT pass validation.
Typical causes of validation errors
Wrong tax categories; invalid unit codes; currency/rounding mismatches; missing BT- identifiers; incorrect country-specific extensions; attachment types not allowed.
Which code lists commonly fail?
UN/ECE unit codes, ISO currency codes, VAT categories, payment means codes, country-specific lists (e.g., Norway EHF specifics; Singapore, A-NZ PASR/PINT).
How to troubleshoot EN 16931 vs BIS errors?
Validate against EN 16931 first, then the Peppol BIS/PINT rules. Use official validators and country validators where provided (e.g., EHF validator in Norway).
TRA
Transport & Security (AS4, PKI)
AS4 transport and OpenPeppol PKI basics.
Which transport is used?
Peppol uses the AS4 profile (peppol-transport-as4-v2_0) with signing and encryption between Access Points.
Common AS4 delivery issues
Expired/soon-expiring certificates; wrong endpoint URL; TLS/cipher mismatch; clock skew; large payloads without compression; retry settings too low.
What about certificates and PKI?
AP/SMP certificates must follow OpenPeppol PKI policy. Track notBefore/notAfter, chain validity, OCSP/CRL status, and plan rollovers ahead.
ONB
Onboarding & Testing
From sandbox to production.
Getting started checklist
Choose a certified AP, register ISO 6523 ID, set SMP capabilities, validate UBLs (EN 16931 + BIS/PINT), pilot MLR/Invoice Response, then go live.
Test vs production environments
Use dedicated test SML/SMP and AP endpoints. Never reuse test identifiers in production.
Cutover best practices
Dual-run with sample partners, monitor MLR/errors, confirm tax reporting dependencies, and communicate timelines to trading partners.
OPS
Operations & Monitoring
What to measure and how to react.
What should we monitor day-to-day?
Validation outcomes, SMP changes, endpoint health, AS4 retries, MLR/Invoice Response feedback, certificate expiry, and message latency.
How to handle rate limits and public lookups?
Cache results, respect rate limits, prefer provider-side APIs, and avoid scraping public endpoints during peak times.
Retention and audit trails
Keep message metadata (hash, timestamps, sender/receiver IDs, doc IDs), validation reports, and MLR/IR responses according to policy and law.
PRI
Data Protection & Legal
GDPR, local laws, and responsibilities.
Is Peppol GDPR-compliant?
Peppol defines secure transport and identifiers, but compliance remains your responsibility: lawful basis, retention, data subject rights, and DPIA where required.
Does Peppol replace tax reporting?
No. Some countries require additional e-reporting/CTC processes. Check national mandates beyond document transport and validation.
TRO
Troubleshooting
Frequent issues and quick checks.
Delivery fails but the participant is “found” online
A directory hit is not proof of capability. Verify SMP for the exact documentTypeID and processID. Ensure your AP targets the listed AS4 endpoint.
Validation fails on totals or tax
Check rounding (line vs invoice level), currency precision, tax category consistency, and allowances/charges distribution per EN 16931 rules.
Attachments rejected
Only certain MIME types and sizes are allowed. Ensure base64 encoding/meta are correct and filenames are ASCII-safe if required.
429 Too Many Requests from public endpoints
Throttle, add backoff, and prefer your provider’s APIs. Batch SMP lookups and cache results.
COU
Country Profiles & Local Models
How Peppol or EN 16931 is used locally.
Belgium
B2B e-invoicing becomes mandatory from 1 Jan 2026 (phased). Peppol is confirmed as the default for issuing structured invoices. B2G already in place.
Germany
From 1 Jan 2025, businesses must be able to receive EN 16931 e-invoices; issuance obligations phase in through 2028. XRechnung/ZUGFeRD align with EN 16931.
France
E-invoicing/e-reporting phased from Sept 2026; DGFiP is the Peppol Authority. Model involves PPF/PDP and Peppol interoperability.
Norway
EHF Billing 3.0 built on Peppol BIS 3.0; extensive public/private use.
Singapore (InvoiceNow)
National e-invoicing based on Peppol; IMDA is the authority. Guides available for service providers and GST considerations.
Australia & New Zealand
PINT A-NZ is the current model; A-NZ BIS 3.0 extension was deprecated in 2025 to migrate toward PINT.
Malaysia
PINT Malaysia specializations (Billing/Self-billing) published under OpenPeppol Post-Award documentation.
Italy
National B2B uses SDI (FatturaPA). Peppol can be used for cross-border or with partners/APs that support it, but SDI remains mandatory domestically.
DEV
Developer & Ops Tips
Practical guidance for implementers.
Safe SMP lookup patterns
Batch and cache lookups; respect SML/SMP TTL; use provider APIs where available; verify both documentTypeID and processID.
Handling certificates
Monitor validity windows, automate renewal alerts, verify chains, and test endpoints after rollover. Keep clocks in sync (NTP).
Observability
Log correlation IDs, participant IDs, doc IDs, SMP URL, endpoint URL, validation results, and MLR/IR payloads to aid audits.
Resilience
Use exponential backoff for AS4 retries, implement idempotency on sender side, and monitor throughput/latency SLAs.
GLO
Glossary
Access Point (AP)
Certified gateway that validates and exchanges AS4 messages in the Peppol network.
SMP / SML
SMP stores capabilities/endpoints; SML points to the correct SMP using DNS.
BIS Billing 3.0
Peppol CIUS of EN 16931 for Invoice and CreditNote.
PINT
Peppol International Invoice Model; base for global/country specializations.
AS4
Secure, reliable message transport profile used by Peppol APs.