Mandatory E-Invoicing 2025: What Online Shop Owners Need to Know

1. What is mandatory e-invoicing and what is it about?

With the Wachstumschancengesetz, the German legislature amended Section 14 of the Umsatzsteuergesetz, the VAT Act, creating the legal basis for a new obligation around invoices exchanged between businesses in Germany. At its core, invoices for domestic business-to-business transactions, known as B2B, must now be issued and received as structured electronic invoices. A structured e-invoice is something different from what most people first assume: sending an invoice as a PDF file by email is not enough. What is meant is a machine-readable format that complies with the European standard EN 16931, for example the pure XML format XRechnung or the hybrid format ZUGFeRD, which combines a human-readable PDF view with embedded structured data. Germany is implementing early a development that was foreseeable at European level anyway, since the European Union is also pushing electronic invoicing forward across cross-border trade through its "VAT in the Digital Age" initiative.

The distinction sounds technical at first, but the underlying idea is simple: a structured e-invoice can be automatically read and processed by accounting and ERP systems, without anyone needing to type numbers in by hand. An ordinary PDF invoice, by contrast, only counts under the new rules as a so-called "sonstige Rechnung", meaning a simple invoice without the machine-readable structure. It is also important to understand that the new rule applies exclusively to domestic transactions between businesses established in Germany. Invoices to private consumers, meaning classic B2C business, are not covered by this obligation and can continue to be issued as before. In practice, for a shop owner this means: as long as you sell exclusively to private customers, nothing changes for now in how you invoice your own customers, though it may well change what you receive from your own suppliers.

The background to the reform is also fiscally motivated: structured, machine-readable invoice data makes it easier for tax authorities in the medium term to detect VAT fraud more quickly, because invoice data can in future be evaluated in a more automated way. For honest shop owners, this changes little about their actual tax obligations, but it does change the form in which invoices will be exchanged going forward. Anyone who treats this topic as a purely formal matter with no practical impact underestimates how much technical preparation can be needed behind the scenes before invoicing processes run smoothly and automatically.

2. Since when does it apply?

Precision matters here, because there are actually two different dates that are often confused with each other. Since 1 January 2025, the so-called receiving obligation has already been in force: every business established in Germany must be technically able to accept and process a structured e-invoice from that date onward, whenever a business partner sends one. This receiving obligation applies from day one to everyone, regardless of company size. Anyone who does not know this distinction between the receiving and the issuing obligation easily underestimates how urgent the topic already is today.

The obligation to issue structured e-invoices yourself was, by contrast, introduced in stages and depends on the issuing company's turnover in the previous year. Through the end of 2026, businesses may still issue paper invoices or, with the recipient's consent, simple PDF invoices for transactions carried out in 2025 and 2026. From 1 January 2027, businesses with a previous year's turnover exceeding 800,000 euros must issue their domestic B2B invoices as structured e-invoices. From 1 January 2028, this issuing obligation then applies, in principle, to essentially all businesses regardless of turnover, since the general transitional rules expire at that point. This staggered rollout is meant to give both larger and smaller businesses enough time to switch their accounting and invoicing processes calmly, rather than forcing every business to the same cut-off date.

It is also worth noting the geographic scope at this point: the deadlines described apply to domestic transactions between businesses established in Germany. Invoices to business partners abroad follow different rules, which can vary from country to country. If you have both domestic and cross-border business relationships, treat the two areas separately rather than assuming a single deadline applies to all your invoices.

3. Who is affected, does it also apply to small shops?

Yes, explicitly also to small online shops and to businesses using the small-business VAT exemption under Section 19 UStG, so-called Kleinunternehmer. This is exactly the point many shop owners overlook, because media coverage often makes the topic sound as if it only concerns large corporations with their own SAP department. In fact, the receiving obligation has applied since 2025 to every business established in Germany that conducts business with other businesses domestically, whether it is a part-time one-person shop or a larger trading company. As soon as another German business sends you a structured e-invoice, for example your hosting provider, a software vendor, or a wholesaler, you must be technically able to open and process that file, not merely view a human-readable PDF version of it. Anyone who believes this topic only concerns businesses with turnover in the millions holds a dangerous misconception that can quickly lead to unpleasant surprises.

As described in the previous section, the obligation to issue your own structured invoices does come with a longer transition period for smaller businesses with lower turnover. However, if you already conduct meaningful business with other companies today, for example because resellers or wholesale customers are among your buyers, you should not postpone switching your own invoicing process until the very last deadline. If, on the other hand, you sell exclusively to private consumers, the issuing obligation does not apply to you at all, but you should still keep the receiving obligation for incoming supplier invoices in mind. Because supplier invoices often arrive unnoticed in the middle of everyday business, it is worth tackling the topic proactively rather than waiting until the first e-invoice actually sits in your inbox and cannot technically be opened.

A typical real-world example: a small one-person online shop buys goods from a German wholesaler and uses a German hosting provider for its own shop. Both business partners can send structured e-invoices from now on, once they have adapted their own systems accordingly. If the shop owner cannot open these files because their own accounting software does not support the format, unnecessary extra work follows through queries and manual rework, even though the shop itself is not yet obliged to issue structured invoices of its own.

4. Deadlines and thresholds at a glance

Because the various deadlines are easy to mix up, a compact overview is worthwhile, one you can also look up again later if needed. The table below summarizes the most important dates and the businesses affected at each stage. Keep this overview handy as a bookmark, since the dates involved stretch across several years.

For your own planning, it is worth looking at your last completed year's turnover, since that figure ultimately decides your issuing deadline. If you are close to the 800,000 euro threshold or expect to grow beyond it soon, you should tackle the switch sooner rather than later. Even if you are well below the threshold, early preparation still pays off, because the receiving obligation already applies now and a solid system for both directions, receiving and issuing, is useful either way.

5. What you concretely need to do

The first sensible step is to check whether your current accounting, point-of-sale, or ERP software is already able to receive and open structured e-invoices in the XRechnung or ZUGFeRD format. Many common programs have added this capability or offer it through an update, but it is worth asking specifically rather than simply assuming it. At the same time, you should think about how incoming e-invoices should reach you, for example through a dedicated email inbox, and how those files will subsequently be archived, since the usual retention obligations also apply to e-invoices. If you work with an external tax advisor or accounting firm, clarify directly with them who will be responsible in future for technically receiving and processing the invoices.

If your shop also does business with other companies, for example in wholesale or with resellers, you should additionally clarify with your tax advisor which turnover threshold applies to you personally and whether you therefore fall under the deadline starting 2027 or only 2028. If you already know that you will need to issue structured invoices in the foreseeable future, it is worth starting the switch earlier rather than waiting until the last moment, when many other businesses may be searching for suitable solutions at the same time. The checklist below summarizes the most important steps once more.

A trial exchange with a single supplier or customer often reveals more quickly than any description where something is still missing in your own process. Smaller technical hiccups are far easier to fix during a controlled test than in the middle of normal daily business, when orders and customer queries are already competing for attention. Once you have completed such a trial run successfully, you can approach the rest of the switch with considerably more confidence.

6. Risks of non-compliance

Unlike some other regulations, mandatory e-invoicing does not come with a single, clearly defined fine that could simply be named. The real risk lies elsewhere and can, over time, become more costly for a business than a fixed fine: an invoice that does not meet the new formal requirements may not be recognized as a proper VAT invoice. That, in turn, can jeopardize the recipient's input VAT deduction, meaning the ability to reclaim the VAT paid from the tax office. This indirect nature of the risk makes the topic tricky, because consequences often only surface months later during a tax audit, once the invoice in question has long since been booked.

In practice, this means primarily an increased tax risk and more friction in dealing with the tax office, for example through queries or formal objections during a tax audit, rather than a single fixed fine. A recipient who is technically unable to open an e-invoice at all also risks delays in their own bookkeeping and, in the worst case, disputes with business partners if invoices cannot be processed in time. Precisely because there is no simple, headline-grabbing fine amount here, many smaller businesses underestimate this topic, even though the risk ultimately affects their own tax position and their own bookkeeping. Businesses that invest early in a working technical solution almost always save themselves this after-the-fact effort entirely.

Another often overlooked aspect concerns retention: structured e-invoices are also subject to the statutory retention periods and must be archived in a way that keeps them readable and machine-evaluable during a later audit. Anyone who simply leaves incoming e-invoices as an attachment somewhere in an email inbox risks being unable to demonstrate proper record-keeping if it ever matters. A structured filing system, ideally directly within the accounting software, effectively prevents this additional risk.

7. Common misconceptions

Probably the most common misconception is: "I send my invoices as a PDF by email, that already counts as an e-invoice." Under the new rules, that is exactly not the case. An ordinary PDF file still only counts as a so-called "sonstige Rechnung", not as a structured e-invoice within the meaning of the law. Only a machine-readable format such as XRechnung or ZUGFeRD meets the new requirements. A second widespread misconception is the assumption that this only concerns large companies with their own IT department and complex SAP systems. In fact, the receiving obligation has affected every business in Germany since 2025, including small one-person online shops and small businesses using the VAT exemption.

A third misconception is that you only need to become active in 2027 or 2028 and can simply wait until then. That is risky, because those later dates concern only your own issuing obligation. The receiving obligation for incoming e-invoices has, by contrast, already been in force since 1 January 2025, meaning it applies right now. A fourth misconception is the idea that this topic only concerns accounting and has nothing to do with the shop system itself. In practice, invoicing processes often touch the order and shop system as well, especially when a shop also serves business customers with its own B2B functionality.

A fifth, more subtle misconception concerns the seemingly simple solution of "my software already got an update for that". An available update does not automatically mean the new capability has actually been switched on, correctly configured, and tested in everyday use. Anyone who relies solely on a feature's theoretical availability, without ever trying it out in practice, often only discovers the actual gap once a business partner's first real e-invoice arrives and cannot be processed properly.

A sixth misconception is the assumption that switching software can happen quickly, almost overnight. Especially with established accounting or ERP systems that have grown over time and have many interfaces, a clean switch realistically needs several weeks of lead time, including testing and briefing the team. Anyone who plans for that lead time from the start avoids unnecessary stress just before the relevant deadline.

8. What Mironsoft can take care of for you

We know that terms like XRechnung, ZUGFeRD, or EN 16931 can sound intimidating at first to shop owners without a technical background. Mironsoft takes care of the technical assessment for you: together with you, we look at how your online shop and its connected systems currently handle incoming and outgoing invoices, and identify where action is needed before the relevant deadlines get closer. We deliberately speak with you in plain language, without overwhelming you with unnecessary technical jargon.

Beyond that, we support you in selecting and connecting an EN 16931 compliant invoicing solution, whether through a suitable extension in your shop system or by connecting to your existing accounting or ERP software. If your shop also serves B2B customers, we additionally make sure that order and invoicing workflows in the shop are properly prepared well ahead of the respective issuing deadlines, so you are not caught under time pressure at the last minute. That way, you can keep your head clear for your actual business, while we keep an eye on the technical details in the background.

Even after the initial switch, we remain your point of contact, for example if deadlines change, a new business partner expects a different format, or your shop grows and moves into a different turnover bracket. That way, you do not have to keep this topic permanently on your own radar, knowing instead that someone experienced is thinking it through in the background.

Note: this article provides general information about mandatory e-invoicing and does not replace individual legal or tax advice for your specific case.

9. Summary

Mandatory e-invoicing is one of the most far-reaching changes to B2B business practice in Germany in recent years. Since 1 January 2025, every business established in Germany, regardless of size and turnover, must be technically able to receive structured e-invoices in the XRechnung or ZUGFeRD format. The obligation to issue such invoices yourself follows a staggered timeline: transitional rules apply through the end of 2026, from 2027 businesses with higher turnover must switch, and from 2028 the obligation applies practically to everyone. Once you understand this basic structure, you can approach the topic step by step instead of being intimidated by all the new terminology.

For small shops and businesses using the small-business VAT exemption, it is especially important to understand that the receiving obligation already applies now and does not only become relevant in a few years. Checking early whether your own software can process e-invoices, and clarifying the applicable issuing deadline with your tax advisor, avoids unnecessary time pressure and tax risk. This article offers an initial orientation for that purpose but does not replace individual advice for your specific situation. In the end, you benefit twice over: your bookkeeping becomes more efficient, and at the same time you protect yourself from unnecessary trouble with the tax office.

10. FAQ: Mandatory e-invoicing for shop owners