XRechnung 4.0: What Germany's Next e-Invoice Standard Means for Your Business

Q: What is XRechnung 4.0?

**XRechnung 4.0** is the next major version of Germany's national e-invoice standard, developed by **KoSIT** (Koordinierungsstelle fur IT-Standards). It implements the revised European standard **EN 16931-1:2026**, which was approved by CEN on 13 February 2026 and is expected to be published by mid-2026. If you are unfamiliar with the European core standard, our [EN 16931 explainer](/blog/en-16931-explained) covers the background. This is not a minor update. KoSIT describes it as "a comprehensive further development" of the existing standard - a signal that the changes go well beyond bug fixes or field additions. XRechnung has been Germany's CIUS (Core Invoice Usage Specification) since 2017, adding German-specific rules on top of EN 16931. Version 4.0 will reset the foundation underneath those rules entirely. For any organisation that sends or receives structured invoices in Germany - whether for public procurement or B2B transactions - XRechnung 4.0 will be the standard to comply with going forward.

Q: When will it arrive?

The timeline hinges on the European standard. **EN 16931-1:2026** was approved by CEN in February 2026 and is expected to be formally published by mid-2026. Once that happens, KoSIT will release a pre-release XRechnung 4.0 specification - but this will be for early visibility only, not for production use. The full production-ready package depends on more than just Part 1. CEN also needs to deliver updated syntax bindings to **UBL 2.5** and **CII D25A** (Parts 3 through 6 of the standard), plus validation artefacts. Draft syntax bindings have already been accepted internally by TC 434, with a formal vote scheduled for July 2026. Until those documents are finalised, software vendors cannot build fully conformant implementations. A phased transition is planned, but no hard switchover date has been announced yet. Given that the [German B2B e-invoicing mandate](/country/DE) requires all businesses to issue e-invoices by 1 January 2028, XRechnung 4.0 will likely be the operative format by then. Our [Germany e-invoicing guide](/guides/germany-e-invoicing) tracks the full mandate timeline.

Q: What about ZUGFeRD?

**ZUGFeRD** is Germany's hybrid e-invoice format - a PDF with embedded structured XML using the CII (Cross Industry Invoice) syntax. It is managed by **FeRD** (Forum elektronische Rechnung Deutschland) and has become popular with smaller businesses because it gives you a human-readable PDF and machine-readable data in a single file. ZUGFeRD will also need to align with the revised EN 16931-1:2026. Since ZUGFeRD uses CII rather than UBL, the syntax binding updates from CEN (Parts 3 through 6 of the standard) will determine exactly how ZUGFeRD evolves. The core semantic changes - multi-order invoicing, the new extensions framework - will apply regardless of syntax. For businesses that prefer the hybrid approach, ZUGFeRD will remain an option. But it too will need a version update to stay compliant with the new core model. If you are currently using ZUGFeRD, keep an eye on FeRD's announcements for their own 4.0-aligned release.

What is XRechnung 4.0?

XRechnung 4.0 is the next major version of Germany's national e-invoice standard, developed by KoSIT (Koordinierungsstelle fur IT-Standards). It implements the revised European standard EN 16931-1:2026, which was approved by CEN on 13 February 2026 and is expected to be published by mid-2026. If you are unfamiliar with the European core standard, our EN 16931 explainer covers the background.

This is not a minor update. KoSIT describes it as "a comprehensive further development" of the existing standard - a signal that the changes go well beyond bug fixes or field additions. XRechnung has been Germany's CIUS (Core Invoice Usage Specification) since 2017, adding German-specific rules on top of EN 16931. Version 4.0 will reset the foundation underneath those rules entirely.

For any organisation that sends or receives structured invoices in Germany - whether for public procurement or B2B transactions - XRechnung 4.0 will be the standard to comply with going forward.

What is actually changing?

The strict 'one order - one delivery - one invoice' rule is gone. Multiple orders and deliveries can now sit on a single invoice.

Three major shifts stand out. First, the strict "one order - one delivery - one invoice" relationship model is dissolved. Under the current standard, each invoice maps to a single purchase order and a single delivery. XRechnung 4.0 allows multiple purchase orders, delivery notes, and buyer references to consolidate into a single invoice. This sounds simple, but it will ripple through procurement workflows, ERP configurations, and three-way matching logic across many industries.

Second, the underlying data model has been redesigned to support B2B requirements and align with the EU's ViDA Digital Reporting Requirements. The revision fixes long-standing technical friction points - ambiguous tax category combinations, rounding issues, and a missing goods/services indicator at item level - that previously caused validation errors for service providers. On top of those corrections, the model gains new B2B-specific elements: enriched bank account information, support for cash discounts (Skonto) and multiple payment terms, late-payment penalties, and additional buyer business identifiers. These fields are essential for the transaction-level VAT reporting that ViDA requires from July 2030.

Third, a new Extensions framework lets industry sectors develop proprietary extensions independently through a central "Extension Component Library". Instead of lobbying for changes to the core standard, sectors like healthcare, construction, or automotive can define their own additional fields and maintain them on their own release cycles. XML attachments also integrate into the core model now, where previously they were limited to extensions.

When will it arrive?

The timeline hinges on the European standard. EN 16931-1:2026 was approved by CEN in February 2026 and is expected to be formally published by mid-2026. Once that happens, KoSIT will release a pre-release XRechnung 4.0 specification - but this will be for early visibility only, not for production use.

The full production-ready package depends on more than just Part 1. CEN also needs to deliver updated syntax bindings to UBL 2.5 and CII D25A (Parts 3 through 6 of the standard), plus validation artefacts. Draft syntax bindings have already been accepted internally by TC 434, with a formal vote scheduled for July 2026. Until those documents are finalised, software vendors cannot build fully conformant implementations.

A phased transition is planned, but no hard switchover date has been announced yet. Given that the German B2B e-invoicing mandate requires all businesses to issue e-invoices by 1 January 2028, XRechnung 4.0 will likely be the operative format by then. Our Germany e-invoicing guide tracks the full mandate timeline.

Is it backward compatible?

No. An invoice that passes validation under XRechnung 3.0 will not necessarily be valid under 4.0, and vice versa. In practice, this means your ERP's e-invoice module will need a software update, your e-invoicing provider will need to rebuild their format conversion logic, and any automated three-way matching that assumes one order per invoice will need reworking. It is not a case of adding a few new fields - the XML structure, validation rules, and data groupings are all changing.

KoSIT has already been tightening the timeline on older versions. All XRechnung versions below 3.0 were deprecated in 2025. Versions 2.1 and below will be removed from the Peppol network on 1 August 2026. Versions 2.2 and 2.3 are expected to be deactivated no earlier than 2027.

The practical takeaway: if your systems are still running on anything older than XRechnung 3.0, you are already behind. Getting to 3.0 now is a prerequisite for a smoother migration to 4.0 later.

How does this relate to Peppol BIS 4.0?

Two parallel workstreams are converging. OpenPeppol is developing Peppol BIS 4.0, which will merge the current BIS 3.0 and the newer PINT (Peppol International) specifications into one unified standard. Like XRechnung 4.0, BIS 4.0 will also be built on the revised EN 16931-1:2026. For a broader look at how Peppol works, see our Peppol explainer.

The result is that XRechnung 4.0 and Peppol BIS 4.0 will share the same foundation. In practice, XRechnung 3.0 and Peppol BIS Billing 3.0 are already considered content-equivalent and interchangeable in Germany - a Peppol BIS 3.0 invoice meets XRechnung 3.0 requirements and vice versa. The same alignment is expected at the 4.0 level.

For organisations that operate across multiple European markets, this convergence is good news. A single invoice format built on EN 16931-1:2026 should satisfy both German national requirements (via XRechnung) and the cross-border Peppol network (via BIS 4.0), reducing the number of format variants to maintain.

What about ZUGFeRD?

ZUGFeRD is Germany's hybrid e-invoice format - a PDF with embedded structured XML using the CII (Cross Industry Invoice) syntax. It is managed by FeRD (Forum elektronische Rechnung Deutschland) and has become popular with smaller businesses because it gives you a human-readable PDF and machine-readable data in a single file.

ZUGFeRD will also need to align with the revised EN 16931-1:2026. Since ZUGFeRD uses CII rather than UBL, the syntax binding updates from CEN (Parts 3 through 6 of the standard) will determine exactly how ZUGFeRD evolves. The core semantic changes - multi-order invoicing, the new extensions framework - will apply regardless of syntax.

For businesses that prefer the hybrid approach, ZUGFeRD will remain an option. But it too will need a version update to stay compliant with the new core model. If you are currently using ZUGFeRD, keep an eye on FeRD's announcements for their own 4.0-aligned release.

How should businesses prepare?

Do not wait for the final specification to start planning. First, make sure your systems are on XRechnung 3.0 now - older versions are being actively removed from the network. Second, review any workflows that rely on the "one order, one delivery, one invoice" assumption, because that logic will break under 4.0. If your ERP or procurement system enforces strict one-to-one matching, flag it with your technical team.

Third, check with your e-invoicing provider whether they are tracking the EN 16931 revision and have a migration plan. Any vendor worth working with should already be engaged with the pre-release materials from KoSIT and CEN. If they cannot tell you their 4.0 readiness timeline, that is a red flag.

Fourth, consider the broader German B2B mandate timeline: businesses with turnover above EUR 800,000 must issue e-invoices from 1 January 2027, and all remaining businesses from 1 January 2028. XRechnung 4.0 will likely be the format in play by then. The new GEBA (German Electronic Business Address) - a voluntary Peppol addressing scheme based on the W-IdNr (Business Identification Number) issued by the Federal Central Tax Office - is another piece falling into place. GEBA is optional alongside existing Peppol IDs, but businesses that get their Peppol registration sorted now will have one less thing to worry about when 4.0 arrives. Check the mandate overview and timeline for the full picture.