When e-invoicing goes national, interoperability suffers

Last updated: November 11, 2026

Electronic invoicing is becoming mandatory in more and more countries. Governments are introducing new regulations, digital reporting requirements and electronic invoicing platforms, all with the aim of improving tax compliance and accelerating the digitalisation of businesses.

This is undoubtedly positive, but there is a paradox: while electronic invoicing is supposed to make transactions easier, the growing number of national systems is making international interoperability increasingly complicated. Some countries have adopted Peppol, letting businesses exchange invoices through an open, decentralised network of service providers. Others have built their own platforms, communication protocols or certification schemes. The result is a fragmented landscape in which providers must continuously develop new integrations, obtain local accreditations and adapt to different technical and regulatory requirements — and it is worth asking whether all that complexity is really necessary.

The hidden cost of national e-invoicing systems

Imagine a European service provider with customers in several countries. One of those customers needs to send a few dozen invoices a year to a country that has introduced mandatory e-invoicing through a national platform or a locally regulated network.

To provide that service directly, the provider may have to build a specific integration, undergo certification, implement additional security requirements and maintain the connection as the rules evolve. In some countries, local accreditation requirements make direct access particularly difficult, or even impossible for certain foreign providers. All this for a handful of customers and a small number of transactions. For a large provider processing millions of invoices in that market, the investment may be justified; for a smaller one, or one with limited activity there, it may make no economic sense.

The consequence is that businesses can end up needing different e-invoicing solutions depending on where their customers and suppliers are located. And that is precisely what interoperability is supposed to prevent.

Peppol has already demonstrated another approach

At B2Brouter, we have believed in Peppol from the beginning. We developed our first Peppol Access Point in 2011, one of the earliest implementations of the network, and we have been members of OpenPeppol since the association was created in 2012. Over the years we have seen how a common interoperability framework can transform electronic document exchange.

The principle is simple: a business connects to its chosen service provider, and that provider can exchange documents with any other participant in the network, without a separate technical connection or commercial agreement for every trading partner.

Common standards, shared technical specifications and a common governance framework make this possible. It is the same principle that lets customers of different telecommunications operators call each other without worrying about which network each one uses.

Of course, Peppol does not remove the need for national tax rules or reporting obligations — governments must be able to define their fiscal requirements and ensure compliance. But there is a fundamental difference between setting national tax requirements and obliging every service provider to build or certify a separate technical infrastructure to meet them. A country can preserve its fiscal sovereignty while adopting open, interoperable mechanisms for exchanging business documents. Unfortunately, not every country has chosen that path.

From Bucharest to Milan: discussing interoperability with GENA

Returning from the WE BUILD General Assembly in Bucharest, I travelled to Milan for the latest General Assembly of GENA, where one of the topics discussed was the SP2SP initiative. GENA — the Global Exchange Network Association, originally founded in 2011 as EESPA — represents the service providers that must turn regulatory requirements and interoperability principles into services businesses can actually use. B2Brouter has been a member for five years, and taking part in its activities lets us compare notes with other providers facing the same challenges.

One of those challenges is increasingly clear: how can a service provider offer international coverage when so many countries introduce their own technical and regulatory barriers? That is where SP2SP becomes relevant.

What if service providers could exchange services, not just invoices?

Service providers do not necessarily need to build every capability themselves. A company specialising in international e-invoicing may have excellent ERP integrations, a large customer base and connections to several networks, but little experience with the specific requirements of a given country. Another provider may specialise in exactly that market, with the local accreditations, technical connections and regulatory expertise already in place. Why should the first duplicate all of that when it could collaborate with the second?

This kind of cooperation already exists, usually through bilateral agreements and one-off technical integrations — but managing many bilateral connections creates its own complexity. The idea behind SP2SP, Service Provider to Service Provider, is to explore how that cooperation could become easier and more scalable by building on the existing Peppol infrastructure. Rather than every provider maintaining a separate connection to every specialised partner, a common framework could facilitate the exchange of information and services between them.

An international provider could rely on a locally accredited partner to handle a national invoicing platform while still offering its customers a single point of integration, without exposing customers to the underlying complexity. This is a particularly interesting opportunity for providers that need international coverage but lack the transaction volumes to justify a direct presence in every market.

A pragmatic bridge, not the final destination

SP2SP is still under development, and important questions remain about how it will be implemented and operated, so it is too early to assess its practical impact or assume it will solve every interoperability problem. There is also a risk worth naming: if cooperation between providers depends indefinitely on bilateral arrangements, different formats and market-specific integrations, we could end up reproducing the very complexity Peppol was designed to eliminate.

Its real value should be to make existing fragmentation more manageable while the industry keeps moving towards standardisation and open interoperability — helping providers reach markets that would otherwise be uneconomic to serve, without turning temporary workarounds into permanent substitutes for common standards. In short, SP2SP should complement the principles of Peppol, not weaken them.

Because the worldwide expansion of mandatory e-invoicing is an extraordinary opportunity to modernise financial processes — but if every country builds its own isolated ecosystem, we risk replacing a fragmented paper-based world with a fragmented digital one. Peppol has demonstrated that open standards, decentralised networks and common governance can enable interoperability at scale, although adopting them does not automatically eliminate every national technical or regulatory requirement. What is still missing in many markets is the regulatory and institutional willingness to embrace it.

Until that changes, service providers will need practical ways to cooperate and help their customers operate internationally. Initiatives like SP2SP could help bridge that gap, although much will depend on how they are implemented.
But a bridge should not become a permanent substitute for the road we should have built in the first place.

Governments and regulators designing the next generation of e-invoicing mandates should make open interoperability a fundamental requirement, not an afterthought. Businesses should not have to change service providers, and service providers should not have to rebuild their infrastructure, every time they cross a border.

The ambition should be simple: any business, in any country, should be able to exchange electronic invoices with any other business through the service provider of its choice. It is time to make that a reality, not just an aspiration.