Peppol 4-Corner & UAE
DCTCE 5-Corner Model
How eInvoices travel between businesses through the Peppol network, and how the UAE adds a fifth corner for centralized tax reporting to the Ministry of Finance.
What Is the "Corner" Model?
In electronic document exchange, a "corner" represents a role in the message flow. Instead of every business connecting directly to every other business, the corner model introduces trusted intermediaries — Accredited Service Providers (ASPs) — that handle secure delivery, validation, and routing on behalf of senders and receivers.
This model is the foundation of the Peppol network globally and of the UAE's national eBilling programme. Understanding it is essential for any organization that wants to become an accredited service provider or connect to the UAE eInvoicing ecosystem.
The Peppol 4-Corner Model
The global standard for interoperable electronic document exchange.
Corner 1
Sender
(Supplier / Issuer)
Corner 2
Sender's ASP
(Access Point)
Corner 3
Receiver's ASP
(Access Point)
Corner 4
Receiver
(Buyer / Recipient)
How an eInvoice Flows Through the 4 Corners
1. The Sender (C1) creates an eInvoice and submits it to their Accredited Service Provider.
2. The Sender's ASP (C2) validates the document against Peppol BIS rules, looks up the Receiver's ASP via the SMP/SML discovery service, and transmits the document using the Peppol AS4 transport protocol.
3. The Receiver's ASP (C3) receives and validates the inbound document, verifies the digital signature and certificate trust chain, and delivers it to the Receiver.
4. The Receiver (C4) receives the eInvoice in their system for processing, matching, and payment.
Federated Network
No central hub processes every message. ASPs exchange documents peer-to-peer, making the network scalable across borders and jurisdictions.
Dynamic Discovery
The Service Metadata Locator (SML) and Service Metadata Publisher (SMP) allow any ASP to discover which ASP serves a given recipient, eliminating manual configuration.
End-to-End Trust
Peppol AS4 provides message-level security with digital signatures, certificate-based authentication (PKI), and mandatory TLS 1.2+ transport encryption.
Standard Document Formats
All documents use Peppol BIS specifications built on UBL 2.1. For the UAE, the mandatory profiles are PINT BIS Billing AE and PINT Tax Document Delivery AE.
The UAE 5-Corner DCTCE Model
How the UAE extends Peppol with a central tax reporting platform.
Corner 5
MoF / FTA Tax Platform
EmaraTax
Sender
Supplier / Issuer
Sender ASP
Access Point
Receiver ASP
Access Point
Receiver
Buyer / Recipient
Corner 5: Tax Reporting Platform
MoF / FTA — EmaraTax integration
The central government platform. It does not participate in the C2↔C3 exchange. Instead, it receives structured tax data reported by ASPs after the eInvoice has been exchanged.
● ASPs validate mandatory tax fields before reporting.
● Reporting uses AS4 transport (not API-only).
● Both C2 and C3 report independently to C5.
● Timeline prescribed by the Minister (Decision 243).
● End User verification via EmaraTax before onboarding.
● Enables near real-time compliance monitoring.
Complete 5-Corner Flow
C1 creates eInvoice and submits to ASP.
C2 validates against UAE PINT BIS rules (TRN, tax fields).
C2 discovers C3 via SML/SMP and transmits via Peppol AS4.
C3 receives, validates, and delivers to C4.
C2 reports tax data to C5 via AS4.
C3 reports tax data to C5 via AS4.
C5 correlates both reports and records for tax compliance.
Responsibilities by Corner
What each participant in the model is responsible for.
Sender & Receiver (End Users)
✓ Appoint an Accredited Service Provider before the applicable deadline.
✓ Provide accurate business data (TRN, legal name, address) to their ASP.
✓ Notify their ASP of any registered-data changes within 5 business days of Authority confirmation.
✓ Issue/transmit eInvoices and eCreditNotes within prescribed timelines.
✓ Retain eInvoicing records per Tax Procedures Law requirements.
Accredited Service Provider
✓ Validate eInvoices against Peppol BIS and UAE PINT rules before exchange.
✓ Discover and route documents to the correct receiving ASP via SML/SMP.
✓ Transmit and receive documents securely via Peppol AS4 with PKI certificates.
✓ Report tax data to Corner 5 (MoF/FTA) within the prescribed timeline.
✓ Verify End Users via EmaraTax before onboarding them onto the network.
✓ Store and archive all eInvoicing data within the UAE.
✓ Notify the Authority of system failures within 2 business days.
Government Platform (MoF / FTA)
● Receives tax data reports from both the Sender's ASP and Receiver's ASP.
● Correlates sender and receiver reports for cross-validation.
● Provides EmaraTax APIs for End User verification during onboarding.
● Monitors compliance and enforces penalties under Cabinet Decision 106.
● Does not participate in the C2 ↔ C3 document exchange itself.
● Publishes the official list of Accredited Service Providers.
Technical Infrastructure
The protocols and services that make the corner model work.
SML (Service Metadata Locator)
DNS-based lookup service that resolves a participant identifier to the address of their SMP. This is the first step in discovering which ASP serves a given recipient.
SMP (Service Metadata Publisher)
Publishes the endpoint URL, supported document types, and transport profile for each participant registered with an ASP. Queried by the sending ASP before transmission.
Peppol AS4
The message transport protocol based on the OASIS AS4 standard. Provides reliable delivery with digital signatures, encryption, receipt acknowledgments, and certificate-based authentication.
Peppol PKI
The certificate infrastructure that underpins trust. Each ASP receives production certificates from OpenPeppol after conformance testing, used for AS4 message signing and TLS mutual authentication.
PINT BIS Billing AE
The UAE-specific Peppol document profile for eInvoices and eCredit Notes. Based on UBL 2.1 with mandatory UAE fields including TRN, tax categories, and currency (AED). Current version: v1.0.2.
PINT TDD AE (Tax Document Delivery)
The profile used by ASPs to report tax data to Corner 5. Defines the structured payload format and AS4 transport configuration for MoF/FTA reporting. Current version: v1.0.2.
4-Corner vs 5-Corner at a Glance
| Aspect | Peppol 4-Corner | UAE 5-Corner (DCTCE) |
|---|---|---|
| Participants | Sender, Sender's ASP, Receiver's ASP, Receiver | Same 4 corners + MoF/FTA platform (Corner 5) |
| Tax reporting | Not built-in; varies by jurisdiction | Mandatory; both ASPs report to Corner 5 |
| Document exchange | C2 ↔ C3 via AS4 | Same C2 ↔ C3 exchange, unchanged |
| Reporting transport | N/A | AS4-based (PINT TDD AE profile) |
| Government visibility | Post-hoc (VAT returns, audits) | Near real-time transaction monitoring |
| ASP obligation | Exchange and deliver documents | Exchange, deliver, validate tax fields, and report |
| End User verification | Per Peppol Authority policy | Mandatory via EmaraTax API before onboarding |
Key Legal References
The official sources that define the corner model obligations for the UAE.
Peppol Interoperability & 4-Corner Model
OpenPeppol official overview
Peppol eDelivery Specifications
AS4, SML, SMP documentation
Peppol AS4 Transport Profile
Message security baseline
PINT BIS Billing AE v1.0.2 Release Notes
UAE profile effective Jan 21, 2026
Ministerial Decision No. 243 of 2025
eInvoicing system rules
UAE eInvoicing Programme Deck
DCTCE 5-corner architecture
Ministerial Decision No. 64 of 2025
ASP eligibility & accreditation
MoF Legislation Index
All eInvoicing decisions
Ready to Connect to the UAE eInvoicing Network?
SolaBill operates as a fully accredited service provider in the Peppol 4-corner and UAE 5-corner models. Get in touch to start your integration.