Deutsche Telekom gets billing system ready for new EU regulation

With new eInvoicing regulation on the horizon in Germany Deutsche Telekom has been replacing elements of its legacy B2B billing platform. The process has unearthed several business benefits, from simplifying and centralizing presentment, right through to generating new ideas about how to turn a legal requirement into a future service for enterprises.

As of 1 January 2027, companies operating in Germany will have to send invoices to other enterprises in the form of an XML file. The country is taking the measure to align with EU regulation to make eInvoicing mandatory for all intra-EU B2B transactions by July 2030.

The EU sees eInvoicing playing a crucial role in simplifying cross-border invoicing and reducing the costs of doing business. The change, however, has posed a challenge to the billing infrastructure of many companies, both inside and outside the telecoms industry, including Deutsche Telekom.

Elements of the communications service provider’s [CSP] legacy enterprise billing systems in its home market of Germany have been in use for around 25 years and were unable to adapt efficiently to upcoming eInvoicing demands, which include the flexible storage and interchange of rich billing data in JSON data files.

Reducing production costs

As a result “we are taking a greenfield approach using TMF 678,” according to Uwe Flüs, team lead for Presentment and Channels, Deutsche Telekom Services Europe SE. “We have [put] the electronic invoice on a new, modern, flexible chain.”

TMF 678 is TM Forum’s Customer Bill Management API, which provides a standardized interface to a customer bill management system.

“Whether we are doing provisioning, wholesale, mass market, individual market it doesn't matter,” explains Flüs. “We have a big database and TMF 678 and we have modules which can take the data out and generate any format you want [for the] electronic invoice and send it to the customer as required.”

Deutsche Telekom Services Europe SE, which built the presentment modules in-house, will trial them with five enterprise customers before the eInvoicing system goes live with 4 million invoices for enterprise customers in Germany as of 1st January 2027.

“It’s a huge change,” points out Flüs. The investment has meant the company was able to get rid of assets such as old portals that it was paying to maintain and instead streamline customers onto a more modern and universal platform.

Flüs now expects maintenance costs to fall since there will be less requirement to test and maintain the stability of legacy systems whenever changes are made.

“Our prediction is that the new production way is much cheaper, because it's smaller modules.

A modular approach

In addition, a new, modular approach provide Deutsche Telekom Services Europe SE with much greater flexibility than the previous monolithic legacy software. As a result, other areas of the business will be able to have greater control of invoicing.

The new invoices will usher in new streamlined processes and the standardized format may mean some teams will have to alter the detail they provide: Flüs likens the shift to eInvoicing to the arrival of email in offices, which initially saw some people print out email messages and file them.

The flip side is that the system “is really flexible,” says Flüs. If an XMLe invoice is done in another area of the company by another team more efficiently and more cheaply than our current IT then we could switch [to them] much more easily than before,” according to Flüs. “You could have multiple partners to deliver different formats or different ways of sending to the customer.”

And because the software is modern, standardized and well-documented new employees can quickly learn how to operate it, he adds.

This creates the potential for companies within the Deutsche Telekom Group to deploy the modules as other EU countries mandate eInvoicing.

Indeed, Deutsche Telekom Services Europe SE plans to near shore the presentment platform and offer it centrally to its Eastern European subsidiaries, which will also have to comply with new European regulation within the next three years.

And further down the line, it could even create the potential for Deutsche Telekom Services Europe SE to offer eInvoicing services to other German companies that have to adapt to the new law.