🔌 Two Technology Pathways — WPSP Choice

Every WPSP must have a UPU-TechCert certified means of connecting to Post*NET and submitting EDI data to the EDI Engine. There are two valid pathways. The choice affects the agreement structure and commercial arrangements.

🚀 Strategic Advantages of RMIG Membership for WPSPs

RMIG membership as a Volume Provider gives WPSPs access to operational, commercial and competitive advantages unavailable through any other postal or logistics framework. The central value: one membership, one certification, access to all RMIG member Destination DOs and their postal customs channels worldwide.

📋 Scope, Purpose & Model Summary

This SOP governs the integration of Wider Postal Sector Players (WPSPs) — commercial consolidators, e-commerce platforms, and logistics providers — into the UPU global postal delivery network under RMIG Interoperability Model 1 (Direct Entry). The WPSP injects item-level EDI data directly into the UPU EDI Engine; the Destination DO delivers the items through its domestic postal network.

🔑 Why S31 Is Required — The S26 Nesting Dependency

UPU Standard S31 ("Assignment of Issuer Codes") governs the issuance of unique network identifiers to entities within the global postal system. For a WPSP, the S31 issuer code is not simply an administrative formality — it is a technical prerequisite for generating valid S26 license plate identifiers.

🏷️ S26 — The Sole Item Identifier in This Model

Every item the WPSP injects into the postal network must carry a valid S26 license plate barcode generated from the WPSP's S31 issuer code. This barcode is the single reference key used by all downstream systems: IPS at the Destination DO, CDS.post for customs pre-clearance, and the UPU Global Track & Trace system for end-customer visibility.

// Master Air Waybill (Commercial)
MWB "999-12345678"
  └── ULD Container
       "AKE12345XX"  // IATA ULD-ID
       └── WPSP Receptacle
            "[facility]EGCAIA26030100123456"
            // 29-char receptacle ID
            └── S26 Item Identifiers
                 // Each S26 built from S31 issuer code
                 "(00) 8<S31-prefix>000000001 4"
                 "(00) 8<S31-prefix>000000002 1"
                 "(00) 8<S31-prefix>000000003 9"

⚙️ Pre-Condition: EventMappingConfiguration

Before any item events are submitted, the WPSP must call POST /EventMappingConfiguration to map its internal operational codes to UPU standard EDI event codes. This is a one-time setup that must be maintained if codes change.

{
  "mapping": [
    { "code": "1", "ediEvent": "EMA", "mailUnitType": "MI", "mailFlow": "O", "name": "Item received at WPSP facility", "valid": true, "preferredReverseMapping": true },
    { "code": "2", "ediEvent": "EMB", "mailUnitType": "MI", "mailFlow": "O", "name": "Item consolidated into receptacle at WPSP", "valid": true },
    { "code": "3", "ediEvent": "EMC", "mailUnitType": "MI", "mailFlow": "O", "name": "Cargo departed — freight forwarder tendered to airline post-export clearance", "valid": true }
  ]
}

🛃 Origin Customs — Export Clearance (EXA → EXC)

Before any cargo can depart the origin country on a commercial or postal basis, it must be presented to the origin country customs authority for export clearance. In the RMIG Model 1 Commercial-to-Post flow, this is the responsibility of the freight forwarder acting as the WPSP's agent at the origin airport or freight terminal. Two EDI events mark this process:

🛃 Postal Customs Channel — Defined and Activated by the Destination DO

This is a fundamental characteristic of the Commercial-to-Post model: although cargo arrives via the commercial airline channel, customs clearance is processed through the postal customs channel — not the commercial import channel. This distinction determines which customs procedures, thresholds, and duty rates apply, and it is the Destination DO's responsibility to designate and operate the postal customs channel for items received from WPSPs.

🌐 UPU Global Track & Trace — End-to-End Shipment Visibility

Every EMSEVT message transmitted through the EDI Engine — from the WPSP's EMA event at origin through the Destination DO's EMI final delivery — is automatically published to the UPU Global Track & Trace (GTT) system, maintained by the UPU Postal Technology Centre. This provides full supply chain visibility to the WPSP, shippers, and recipients without any additional integration work beyond the mandatory EDI events.

🔄 Destination DO Processing Workflow

1. Pre-Arrival: IPS & CDS.post Synchronisation

   On receiving EMC from the WPSP via IPS, the Destination DO pre-loads all item records. CDS.post makes ITMATT data available to national customs for advance risk scoring. Items can be provisionally cleared before the flight lands.

2. Physical Arrival via Commercial Channel — Postal Custody Begins

   The Destination DO collects cargo from the airport freight terminal (commercial channel). From this point, items enter the postal supply chain. The DO scans the ULD or receptacle — IPS returns all linked S26 item data automatically.

3. EMD — Arrival at Inward OE MANDATORY (Dest. DO)

   Destination DO generates EMD event confirming physical receipt. This is returned to the WPSP via IPS and immediately updates the UPU Global Track & Trace system. The WPSP's tracking portal reflects "Arrived at Destination" for end-customer visibility.

4. EDB — Postal Customs Presentation via CDS.post MANDATORY (Dest. DO)

   Destination DO generates CUSITM from the WPSP's ITMATT data and submits to national customs authority via its CDS.post postal customs interface. Customs responds with CUSRSP. Items are processed under postal customs procedures — not commercial import procedures.

5. EMG / EMI — Sorting, Dispatch & Final Delivery

   After customs clearance, items move through the Destination DO's DPS (Domestic Postal System). S26 scans at each facility update IPS and GTT. EMI (final delivery) is generated and visible to the WPSP and end-customer in real time.

💰 Financial Arrangements — Complete Cost Framework

The Commercial-to-Post model replaces the traditional UPU terminal dues mechanism with a set of bilateral and platform-based financial arrangements. Each cost category has a clearly defined responsible party and settlement mechanism.

📊 Complete Requirements Matrix

Key terms used in this matrix are defined in the Glossary below. Legend: Mandatory   Technology Provider (Pathway 2)   Optional

📖 Glossary of Key Terms

🌍 Background & Context

AliExpress has millions of customers in Egypt who buy products from Chinese sellers daily. Those products are collected, consolidated, and shipped internationally by Cainiao — Alibaba Group's global logistics arm and an existing UPU Consultative Committee (CC) member. This case study shows exactly how RMIG Model 1 makes that flow work through the postal network, end-to-end.

In this scenario, Cainiao acts as both the WPSP (responsible for EDI and postal network injection) and the Technology Provider (it has its own certified technology infrastructure). AliExpress generates shipping labels using Cainiao's S31-based GS1 prefix. Goods travel by air from Shenzhen to Cairo and are delivered to Egyptian buyers by Egypt Post — an RMIG member Designated Operator.

🗺️ End-to-End Flow — All Steps at a Glance

Orange-bordered boxes are mandatory EDI events. Plain boxes are physical or supporting steps. The UPU GTT row shows that every event is published to public tracking automatically.

📋 Step-by-Step Walkthrough

💰 Financial Arrangements — This Example

🎯 Key Takeaways from This Example