How to Connect Your ERP to Peppol

For a UK finance team, the “best” Peppol API is rarely just the one with the cleanest developer documentation. It is the one that can handle the real-world mess around ERP data quality, supplier onboarding, invoice exceptions and future compliance changes. Below we’ll answer how to connect your ERP to Peppol, compare API integration options, and prepare your finance systems for compliant eInvoicing.

Your finance team needs accurate invoice data. Your IT team needs a secure connection. Your suppliers and customers need documents in the right format. And your business needs confidence that the process will keep working as eInvoicing requirements continue to evolve.

This practical guide answers the most common questions UK businesses ask when they start looking at Peppol API integration for ERP and finance systems.

Peppol API integration connects your ERP, accounting or finance system to the Peppol network through a certified Peppol Access Point.

Your ERP continues to create, receive and store invoice data. The API acts as the connection between your internal system and the Peppol network, allowing electronic invoices and other business documents to be exchanged securely in a structured format.

Instead of sending invoices by email, PDF, post or customer portals, Peppol allows businesses to exchange invoice data directly between systems. This means fewer manual processes, fewer errors and better visibility of document delivery.

For UK businesses, Peppol can be especially useful when trading with public sector organisations, international customers or companies that are moving towards structured electronic invoicing.

Developers usually connect an ERP system to Peppol using an API provided by a certified Peppol Access Point or managed eInvoicing provider.

The process normally works like this:

The key point is that Peppol integration is not just about sending a file. The data must be complete, structured and compliant with Peppol requirements. Developers need to think about authentication, error handling, message status updates, data mapping, testing and how exceptions will be managed by finance users. A good integration should make the process simple for the end user. Finance teams should not need to understand Peppol syntax or technical validation rules. They should be able to create, send, receive and monitor invoices from within their normal process.

There are three common ways to connect an ERP to Peppol.

The first option is a direct API integration. This is usually best for organisations with internal development resources and a clear integration strategy. The ERP connects directly to the provider’s API, giving the business control over how data is sent and received.

The second option is middleware or an integration platform. This sits between the ERP and the Peppol Access Point. It can be useful when data needs to be transformed, enriched or routed between multiple systems.

The third option is a managed integration service. This is often the most practical route for businesses that want to reduce internal technical effort. A managed provider can support mapping, validation, onboarding, monitoring and ongoing changes. For many organisations, the best approach is not simply the most technical one. It is the one that fits your invoice volumes, ERP setup, compliance needs and available internal resource.

To enable electronic invoicing through Peppol, you need to connect your ERP or finance system to a Peppol Access Point and make sure invoice data can be exchanged in the correct structured format.
The practical checklist is:

For many businesses, the biggest challenge is not the API itself. It is making sure the surrounding process works properly. That includes master data quality, invoice approval workflows, supplier onboarding, customer requirements and exception management.

The best Peppol API is the one that fits your systems, resources and business goals. A developer-led organisation may want detailed documentation, flexible endpoints and full control over the integration. A finance-led organisation may prefer a managed service that reduces technical effort and provides ongoing support. When comparing Peppol APIs, look for:

There are a number of providers that offer Peppol API integration and Access Point services. Some focus mainly on giving developers an API to connect to the PEPPOL network. Others provide broader managed services that include ERP integration, data transformation, validation, onboarding and support.

When choosing a provider, consider whether you need:

Transalis is positioned for organisations that want Peppol to work as part of a wider digital document exchange and finance automation strategy. Rather than treating Peppol as a standalone technical connection, Transalis can help connect ERP systems, finance workflows, suppliers and customers into a more joined-up process.

Peppol API integration is a practical way to connect ERP and finance systems to the growing world of electronic invoicing. For developers, the project involves APIs, data mapping, validation, authentication and status handling. For finance teams, it is about reducing manual work, improving invoice accuracy and gaining better visibility. For the wider business, it creates a more scalable way to trade digitally with customers, suppliers and public sector organisations.

The most successful Peppol projects are not treated as one-off technical connections. They are planned as part of a wider eInvoicing and automation strategy. With the right partner, UK businesses can connect their ERP to Peppol, and together we can build a stronger foundation for future digital trading.