Overview of the eConnect Procurement Service Bus (PSB) API: architecture, capabilities and document types.
The Procurement Service Bus (PSB) is eConnect's central API gateway for sending, receiving and processing e-invoices, orders and other e-documents. The PSB connects your software with the Peppol network and other e-invoicing networks through a modern REST API secured with OAuth2.
Whether you are a software vendor looking to integrate e-invoicing, or an organisation looking to automate document flows: the PSB provides the infrastructure to do so reliably and at scale.
The PSB is more than a sending channel. It is a full-fledged platform for processing e-documents, with functionality that covers the entire purchase-to-pay cycle.
E-invoicing is at the core. Through the API you send sales invoices to recipients on the Peppol network and receive purchase invoices from suppliers. The PSB automatically routes documents to the correct Access Point and confirms delivery with real-time status updates.
E-ordering goes beyond invoicing. The PSB supports sending and receiving orders, order confirmations, order changes and cancellations. Both Peppol Order Only and Order Advanced are supported, as well as DICO messages (including the maintenance message), Coupa and cXML. Orders can be turned ("flipped") into an invoice with a single click.
Self-billing makes it possible to create and send invoices on behalf of a supplier. This is relevant for organisations that prepare purchase invoices themselves based on received goods or services.
Validation offers a standalone endpoint to check XML documents for correctness without actually sending them. The Validate API automatically detects the document format, tests against the most recent artefacts and provides detailed, multilingual feedback per validation rule.
Transformation converts documents from one e-invoice format to another. You submit in the format your software produces and the PSB automatically converts it to the format required by the recipient. The PSB supports more than 20 standards, including UBL 2.1, NLCIUS, Peppol BIS Billing V3, PINT, CII, XRechnung, Factur-X/ZUGFeRD, FatturaPA, ebInterface, Svefaktura, e-FFF, OIOUBL, Finvoice, ISDOC and industry-specific formats such as DICO, SETU and SEEF. The format is auto-detected on upload; you do not need to specify which format you are submitting.
Validated Party Data (VPD) is a GraphQL API that lets you query and verify party data. Check whether a Chamber of Commerce number, OIN or VAT number actually belongs to a specific organisation before sending an invoice. In Control, the same functionality is known under the customer-facing name Purple Pages.
Intelligent Document Recognition (IDR) converts PDF invoices into structured XML using OCR and AI. The IDR can be controlled directly through the PSB API, with configurable quality levels and priorities.
The PSB is built on the Actor model within a Microsoft Azure Service Fabric cluster. That sounds technical, but the benefits are concrete: documents are processed in parallel across multiple servers without waiting for each other. If a server fails, processing automatically continues on another node without data loss.
In practice this means a processing time of less than 100 milliseconds per document when sending, a proven capacity of 200.000 messages per hour and an uptime of 99,99% (more than eight years without unplanned downtime).
The PSB operates as a Peppol Access Point with multiple Access Points in the standard configuration. Volume is dynamically distributed via reliable queues. Each tenant is logically isolated: it is technically impossible to access documents belonging to another tenant. The PSB runs on Microsoft Azure (Netherlands and Ireland regions); all data processing takes place within the EU/EEA.
With a single API integration you gain access to multiple networks. The PSB automatically routes documents to the correct channel based on the recipient.
The PSB is prepared for the EU ViDA directive (VAT in the Digital Age), which makes Digital Reporting Requirements (DRR) mandatory for cross-border B2B transactions from 1 July 2030. When you send an invoice, the PSB automatically generates the DRR summary from the invoice data and submits it to the relevant tax authority. As an integrator you do not need to do anything extra: you send your invoice through the regular API and the PSB handles the reporting.
The PSB implements the Peppol 5-corner model, where the Access Point handles CTC reporting (Continuous Transaction Controls) on behalf of the sender. Status messages, evidence files and CTC reporting messages are included in the document price, at no additional cost per message.
The PSB works event-driven. Instead of periodically polling for new documents, you can configure webhooks that notify your application immediately when relevant events occur: an invoice received, an invoice successfully delivered, a sending error, an Invoice Response from the recipient.
Hooks support multiple action types: HTTPS webhooks, e-mail notifications, SFTP push, and even batch processing where documents are periodically offered as a ZIP archive. Each hook type is secured with HMAC SHA256 signatures.
The PSB uses OAuth 2.0 for authentication, supporting both Client Credentials and Resource Owner Password Credentials flows. All communication runs over TLS 1.2 or higher. Binary uploads are automatically scanned for viruses and malware, and XML documents are validated against standard rule sets.
Each tenant operates in a logically isolated environment. The PSB processes documents for more than 20.000 organisations.
The PSB REST API (v1) is organised around the following endpoint groups:
The full endpoint documentation with request and response formats is available as an interactive Swagger UI. You can download the accompanying swagger.json to generate client code.
Ready to get started? The articles below will help you on your way, from requesting a test account to making your first API call.
The PSB provides endpoints for e-invoicing (send and receive), e-ordering, self-billing, validation, transformation, party data (VPD) and PDF recognition (IDR). With a single API integration you get access to Peppol and other procurement networks.
The PSB processes documents in less than 100 milliseconds when sending, with a proven capacity of 200.000 messages per hour. Uptime is 99,99%, with more than eight years without unplanned downtime.
The PSB uses OAuth 2.0 for authentication, supporting both Client Credentials and Resource Owner Password Credentials flows. All communication runs over TLS 1.2 or higher.
You submit in the format your software produces. The PSB auto-detects the document format and transforms it to the format expected by the recipient. More than 20 standards are supported, including UBL, NLCIUS, BIS Billing V3, PINT, CII, XRechnung, Factur-X, FatturaPA and industry-specific formats such as DICO and SETU. You do not need to worry about the recipient's format.
The PSB is ViDA-ready. When you send an invoice, the PSB automatically generates the DRR summary (Digital Reporting Requirement) from the invoice data and submits it to the relevant tax authority. As an integrator you do not need to do anything extra. Status messages, evidence files and CTC reporting messages are included in the document price.
View the interactive API documentation