What the E-Invoicing Mandate Really Means for SMEs

As Teamlead for SAP Vendor Invoice Management (VIM) at CONVOTIS, Julius Sattler is responsible for projects related to e-invoicing. In this interview, he explains why the e-invoicing mandate is far more than a legal requirement, why many companies still underestimate the need for action and which steps are now crucial.

Julius, as Teamlead VIM at CONVOTIS, you are responsible for implementing e-invoicing solutions. Please briefly introduce yourself to our readers.

My name is Julius Sattler, and I lead the SAP Vendor Invoice Management (VIM) team at CONVOTIS. Together, we support companies in fully digitalizing and automating their invoice processes – from invoice receipt, audit-compliant archiving, processing and approval through to posting in SAP.

What drives my team and me goes far beyond introducing e-invoicing or implementing legal requirements. We are passionate about eliminating paper-based processes, automating manual tasks and helping companies make their financial processes more efficient, transparent and future-ready.

Since January 2025, companies in Germany have been required to receive e-invoices. What is the situation in practice?

Mixed. Although the obligation to receive structured e-invoices in the B2B sector has been in force since 1 January 2025, we are still in a transitional phase. Many companies continue to assume that receiving PDF invoices by email is sufficient. However, this is not the case. A PDF file is not an e-invoice within the meaning of the law. Structured, machine-readable formats such as XRechnung or ZUGFeRD from version 2.0.1 onwards are required – in other words, data formats that can be processed automatically.

At the same time, the entire ecosystem still needs time to settle in. Many suppliers do not yet consistently comply with the requirements, systems interpret data differently and errors occur on both the sender’s and the recipient’s side. Responsibility is then often passed back and forth between those involved, even though successful e-invoice processing can only work when all parties work together.

In addition, many companies have very high expectations. It is often assumed that once e-invoicing has been introduced, invoices can be processed fully automatically and without any manual intervention. In many cases, we are still a long way from this ideal scenario. At present, we are even seeing a higher error rate because new formats, legal requirements and different system landscapes first need to be aligned.

However, I see this as a completely normal maturation process. Standards, systems and processes first need to become established and aligned with one another. In the long term, I am convinced that e-invoicing will lead to significantly higher levels of automation and more efficient financial processes.

What exactly distinguishes a genuine e-invoice from a PDF invoice?

The key difference lies in the structure. A PDF invoice is readable by humans, but for systems it is initially just a document. The information it contains must be extracted using OCR – a process that always carries a certain risk of errors due to the discontinuity between formats and the interpretation of the document content. OCR can therefore never guarantee completely reliable data recognition.

A genuine e-invoice such as XRechnung or ZUGFeRD, by contrast, already contains the invoice data as structured XML. The information is machine-readable, standardized and validatable, and can be transferred directly into ERP systems and processed automatically without OCR. This ensures significantly higher data quality and provides the basis for largely automated invoice processing. ZUGFeRD also includes a readable PDF that appears familiar to the supplier. However, the XML in the background is what matters for processing within the system. This is where the real paradigm shift lies.

Which deadlines do companies need to keep in mind now?

The transitional phases may appear complex, but the key points can be clearly defined: Receiving and processing e-invoices has been mandatory since January 2025. Staggered transitional deadlines apply to sending e-invoices until the end of 2026 – for companies with annual revenue of less than EUR 800,000, this deadline is extended until the end of 2027.

From 2028, the obligation will apply in full, including the sending of outgoing invoices in the B2B sector. There are also EU-wide requirements under the ViDA initiative, which will extend the topic beyond national borders in the future. Anyone who says today that there is still plenty of time is significantly underestimating the effort involved in such a project.

Which formats and standards should companies be familiar with?

The most important formats in the DACH region are XRechnung and ZUGFeRD. XRechnung is the national standard in Germany and is particularly relevant in the B2G sector – in other words, when issuing invoices to public authorities. ZUGFeRD is a hybrid format: a PDF plus embedded XML that complies with the European standard EN 16931. There is also PEPPOL, an international transmission network that is becoming increasingly important, particularly for cross-border business. Our solution at CONVOTIS supports all these formats – both incoming and outgoing. This is important because companies often cannot choose which formats their suppliers or customers send them.

What does a typical implementation at CONVOTIS look like?

We always start by analysing the existing SAP landscape – whether SAP ECC, S/4HANA or hybrid environments. We then integrate OpenText VIM as the central platform for incoming invoice processing – CONVOTIS is a certified OpenText partner. We connect the e-invoicing interfaces for outgoing invoices and configure the validation logic: mandatory fields, formats and tax requirements. The result is a fully automated end-to-end process – from the incoming invoice through to posting in SAP, archived in compliance with GoBD requirements and documented in an audit-proof manner. We provide both the implementation and ongoing Level 1 to Level 3 support.

What is the most common mistake companies make when introducing e-invoicing?

The most common mistake is addressing the topic too late and underestimating the effort involved. Many companies still regard e-invoicing as a purely technical integration. In reality, however, the actual work only begins afterwards: Suppliers need to be integrated, internal approval processes adapted, validation rules defined and employees trained.

The testing phase is also frequently planned too tightly. Too few test cases are considered or only standard scenarios are tested. With e-invoicing in particular, however, the devil is in the detail.

Let me give you an example from practice: A customer receives a PDF that the system correctly identifies as a ZUGFeRD invoice. The system detects and extracts the embedded XML file. The XML then contains further embedded PDF documents, which must also be processed correctly. This single incoming PDF therefore introduces four invoice documents into the workflow. Such cases may seem inconspicuous at first, but they can quickly become complex.

In addition, a successful implementation does not automatically work internationally. Just because e-invoices are processed correctly in Germany does not mean that the same applies to countries such as Belgium, France or Poland. Different formats, validation rules and legal requirements may apply in these countries.

My most important advice is: Do not look only at the e-invoice, but at the entire purchase-to-pay process. Question existing approval processes, waiting times and manual tasks, and examine which processes can be standardized or automated. The greatest efficiency gains usually come not from the XML format itself, but from optimizing the entire invoice process.

What benefits does a company gain by consistently implementing the e-invoicing mandate – beyond compliance and also from a strategic perspective?

Compliance is the reason, but automation is the real benefit. Companies that take e-invoicing seriously can drastically reduce manual steps in accounting. Shorter processing times mean that early-payment discount deadlines can be met – a directly measurable financial benefit. Errors caused by manual data entry are eliminated. Transparency regarding the status of every invoice increases. And companies that switch to structured e-invoice formats at an early stage are already prepared for future requirements – such as ViDA at EU level. The obligation should not obscure the opportunities.

What do you recommend to companies that have not yet started?

Start now. Analyse your incoming invoices, check which formats you already receive and determine whether your SAP landscape can receive and process e-invoices. A structured roadmap should then be created based on these findings.

My advice is not to limit the project to meeting the minimum legal requirements. E-invoicing should be used as an opportunity to optimize the entire purchase-to-pay process. The objective should be structured processing with automatic validation, digital approvals and the highest possible degree of automation. The greatest added value does not come from the XML format itself, but from more efficient and highly automated processes.

CONVOTIS offers individual demo sessions with our SAP and e-invoicing experts, during which we demonstrate the situation directly within the system. This quickly provides clarity on where the greatest need for action lies.

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Julius Sattler, Teamlead VIM at CONVOTIS · LinkedIn Profile