On 15 October 2026 Germany’s Federal Ministry of Finance (BMF) issued a third official letter on e-invoicing — like the letters of 2024 and 2025, on a 15 October. It brings together clarifications the ministry had so far only given in replies to trade associations, amends the VAT Application Decree (UStAE) and grants a grace period until the end of the year. Eleven weeks before 1 January 2027, this is the standard German invoices will be checked against from the turn of the year.
As of 16 October 2026. BMF letter of 15.10.2026, ref. III C 5 - S 7287-a/00019/021/017, “Introduction of mandatory electronic invoicing for supplies between domestic businesses from 1 January 2025”. The details below follow the first analyses in the German specialist press; the binding text is the letter itself on the BMF website.
What the letter is
Since February 2026 the BMF had answered several questions in letters to individual associations — from the trades, industry and the energy sector, for example on construction invoicing, invoice corrections and the obligation from 2027. None of it was officially published, so businesses could rely on it only to a limited extent. The new letter consolidates the key points, adds further rules and writes them into the UStAE. It applies to supplies after 31 December 2024; the statutory transition rules to the end of 2026 and the end of 2027 are unchanged — who has to issue e-invoices and when is covered in Germany’s e-invoicing obligation in 2027.
Grace period until 31 December 2026
An e-invoice issued by 31 December 2026 that meets the 2024 and 2025 letters but not yet the additional requirements of 15 October 2026 will not be challenged by the tax authorities — expressly including the recipient’s input VAT deduction. In practice: switch over by year-end; from 2027 the new standard applies without leniency.
The key points
All mandatory details belong in the XML
The details required by § 14(4) and § 14a of the German VAT Act must be in the structured part; for the mapping the authorities refer to the tables published by KoSIT and FeRD. The description of the supply must allow its tax treatment to be assessed — a mere reference to a contract is not enough, and neither is a pointer to information in an unstructured attachment. Anything beyond that, such as timesheets, may travel as an embedded attachment. The visible PDF page of a ZUGFeRD invoice does not count here: the XML is what matters.
Corrections only as e-invoices
If the original invoice had to be an e-invoice, so does the correction — with the invoice type for a correction (in the EN 16931 code list that is 384) and a clear reference to the original invoice. The BMF does not prescribe a particular technique — replacement, difference or cancellation invoice. The old “red pen” method, where the recipient marks errors on paper and the issuer agrees, now only works for other (non-structured) invoices. The recipient may also correct an e-invoice by a self-billed credit note if this was agreed and the credit note clearly identifies the original invoice. Where credit notes and corrections sit in the XML is shown in XML structure.
Validation helps, it is not a condition
Validation is not a legal prerequisite for an e-invoice to be valid; it is a way to demonstrate the formal requirements are met. There will be no government validation tool, and the BMF does not recommend vendors. On error types, the 2025 line stands: a business-rule error only matters for VAT if it affects a mandatory detail.
Construction and down payments: relief until mid-2030
For construction work, until 30 June 2030 the structured part may contain only totals per trade, provided a readable attachment breaks them down by the bill of quantities and the XML expressly refers to it. For final invoices after down payments, the authorities accept until the same date that prepaid amounts are deducted as a total, with the details in the invoice note or an embedded attachment.
When the issuer did not know the customer was a business
The obligation only applies to businesses buying for their business. If the issuer could not have recognised this even with due care, a missing e-invoice will not be challenged. For long-term contracts, a check at the start of the contract or when it changes is enough.
What to do now
- Review descriptions of supplies. Where an invoice only says “as per contract no. …”, a real description has to go into the XML by year-end.
- Settle how you correct invoices. If you must issue e-invoices from 2027, you also need software that produces type 384 with a reference to the original invoice.
- Keep validation reports. Validation is not a condition, but it is the simplest proof that format and mandatory details are right — more in Validating e-invoices.
- In construction, plan the attachment. Totals per trade in the XML, the bill of quantities readable alongside, a reference in the XML.
- Clear individual cases with your tax adviser. The letter is long, and the specialist press does not read every point the same way.
Frequently asked questions
Do I have to reissue invoices I issued in 2026?
No. E-invoices issued by 31 December 2026 that meet the 2024 and 2025 letters will not be challenged, including for input VAT deduction.
Does the letter change the deadlines for 2027 and 2028?
No. The transition rules are set by statute (§ 27(38) of the German VAT Act) and stay as they are: from 2027, issuing is mandatory above €800,000 prior-year turnover, from 2028 for everyone.
Is an invoice invalid if the validator reports an error?
Not automatically. Validation is not a legal prerequisite. A format error does, however, strip the file of its e-invoice status, and a business-rule error counts if it affects a mandatory detail.
Can E-Rechnung Pro create correction invoices?
The form issues ordinary invoices. If you upload a printed correction or cancellation invoice to the converter, it carries over type 384 and the number of the original invoice, as far as the document shows it.
In short
- Third official BMF letter on e-invoicing, dated 15 October 2026, with amendments to the VAT Application Decree.
- Grace period: e-invoices up to 31 December 2026 under the previous standard will not be challenged.
- All mandatory details in the XML, no bare contract reference; corrections of an e-invoice again as an e-invoice.
- Validation is proof, not a condition; relief for construction and down payments until 30 June 2030.
Check whether your invoices meet the format and business rules free of charge, without signing up — the report names every rule broken, with its code.
E-Rechnung Pro creates and validates documents against EN 16931:2017 — the version ZUGFeRD 2.x and Factur-X are built on today. We are following the EN 16931-1:2026 revision and will support it as the formats adopt it.