Germany’s Ministry of Finance (MOF) has published a second administrative guidance letter (15 Oct 2025) on domestic mandatory B2B e-invoicing, addressing uncertainties left by the initial guidance (15 Oct 2024) and FAQs (5 Feb 2025). The new letter applies to supplies carried out after 31 Dec 2024 and operates alongside staggered transitional arrangements through 31 Dec 2027. Since 1 Jan 2025, e-invoicing for domestic B2B transactions has been mandatory in Germany, but the MOF has now clarified how to treat different error categories, the role of validation, and the location of mandatory data in the structured invoice. It also confirms receive-readiness, the exercise of VAT options, limited exceptions, reductions, and retention rules.
This article translates those legal clarifications into operational guidance for finance, tax, and IT teams—so you can update controls, templates, and systems with confidence.
1. Scope and Timing—Where We Stand Now
- In force since 1 Jan 2025: Domestic B2B e-invoicing is mandatory.
- Applicability: The second guidance applies to all supplies after 31 Dec 2024.
- Transition: Transitional arrangements run to 31 Dec 2027 for invoice issuers (staggered roll-out, e.g., by business size/complexity).
- Receive-readiness: From 1 Jan 2025, even entities benefitting from certain issuance exemptions must be able to receive e-invoices.
What this means in practice: Every German business engaging in domestic B2B must plan for full issuance and receipt in structured format, while aligning with transitional reliefs until the end of 2027.
2. Error Categories—Definitions and Consequences
The MOF distinguishes three error classes. Understanding them is critical for both issuers and recipients and should be reflected in your ERP validations and AP controls.
2.1 Formatting errors (syntactic/technical)
A formatting error means the file does not meet syntax or technical requirements, or does not allow correct and complete data extraction. Such a file is not an e-invoice; it is an electronic document in a non-compliant format.
Operational implication: Implement schema and syntax validation before transmission (e.g., EN 16931/XRechnung validators). If a formatting error is detected, do not post or transmit as a valid e-invoice.
2.2 Business rule errors (logical checks)
A business rule error arises when the invoice fails technical rules that check the logic within the data (completeness/consistency). Examples include missing BT-10 Buyer Reference in an XRechnung file or inconsistent VAT totals vs. VAT fields.
- Important nuance: If the breached rule does not concern mandatory invoice details, the error can be insignificant (e.g., missing BT-10, depending on context).
Operational implication: Separate blocking vs non-blocking business rules in your validator. Non-mandatory rule failures may be logged for follow-up rather than blocking issuance.
2.3 Content errors (mandatory invoice details)
Content errors affect the mandatory invoice details under sections 14(4) and 14a of the German VAT Act. These render the invoice non-compliant.
- They can be detected by business-rule validation, but not always; some content errors may escape automated checks.
Operational implication: Maintain post-validation reviews and AP three-way checks. Do not rely solely on automated validators to confirm legal sufficiency.
3. Validation—What it Can (and Cannot) Prove
The MOF confirms that validation may check EN 16931 compliance using “suitable validation applications.” Validation at issuance is a secondary function; recipients must still examine completeness and accuracy. However:
- If due diligence is exercised (the standard of a prudent businessperson), the taxable recipient may rely on the format and business-rule checks.
- Retaining the validation report is evidence of due diligence.
4. Where Mandatory Data Must Live: Inside the Structured XML
The MOF reiterates that mandatory invoice details must be present in the structured data of the e-invoice itself.
- Merely referencing an attachment that contains mandatory details is insufficient.
- A link to an external source likewise fails legal requirements.
Operational implication: Ensure that your mapping templates place all legally required data (supplier/buyer identifiers, tax amounts, item details, etc.) in the XML (e.g., XRechnung/EN 16931 fields). Attachments (PDFs, CSVs, images) can supplement, but cannot substitute required fields.
5. Issuance Duty When Opting for Taxation (§9(1) UStG)
Where a service becomes taxable due to the exercise of the option under §9(1) of the VAT Act, the e-invoicing obligation applies.
Operational implication: If you opt to tax otherwise exempt supplies, your issuance must follow the structured e-invoice rules.
6. Optional e-Invoicing in Specific Cases—what Remains Out of Scope
- Low-value invoices ≤ EUR 250 and travel tickets are not subject to the issuance obligation.
- Small business scheme taxpayers (Kleinunternehmer) are not required to issue e-invoices but must be able to receive them from 1 Jan 2025.
- Even in these cases, e-invoices may be issued and transmitted without recipient consent, subject to further legal requirements.
7. Reductions, Corrections, and Self-billing
A reduction in the tax assessment basis under §17 UStG (e.g., discounts or defect-related price reductions that do not affect the original supply) does not create a blanket duty to correct invoices.
- Distinguish between commercial adjustments that do not change the scope/content of the supply, and changes that do—the latter may require a corrected description.
- Subject to prior agreement, a correction may be made via a self-billing document, provided it specifically and unambiguously references the original invoice.
8. Retention and Integrity
Taxable persons must retain a copy of every incoming and outgoing invoice for eight years. For e-invoices, at least the structured part must be retained intact and in original form.
- Storage outside a GoBD-compliant system is not automatically a breach of content integrity, provided the original structured data remains unaltered and accessible.
9. Practical Clarifications from the MOF (Frequent Scenarios)
9.1 The buyer is not ready to receive an e-invoice
If the issuer has created the e-invoice and can demonstrate transmission efforts (e.g., access-point logs, delivery attempts), the issuer’s VAT obligations are considered fulfilled.
9.2 Recipient’s duty of care and validation artifacts
Recipients remain responsible for checking completeness and accuracy. Retaining validation outputs (format + business rules) supports due diligence, though it may not detect every content error.
