SAP Business One in Germany: E-Rechnung, DATEV, GoBD

SAP Business One runs in Germany on an official SAP localization, so the German VAT setup, tax reports, DATEV export and e-invoice formats come from SAP itself. What changes for German companies right now is the e-invoice: receiving has been mandatory since 2025, and issuing becomes mandatory in 2027 or 2028. This page sets out what the localization covers, which dates apply, and where custom development on SAP B1 helps.

I am Zain Abbas, a SAP Business One developer. For 2.5 years I worked as part of a German company’s team on SAP B1 production add-ons, web portals and a 3CX phone integration. That is the German experience behind this page; the rules below come from the Federal Ministry of Finance (BMF) and SAP documentation, linked at the end.

What does the German localization of SAP Business One include?

SAP ships SAP Business One with country localizations, and Germany is one of them (so are Austria and Switzerland, each with its own localization). The SAP Help Portal guide “Localization for Germany” for release 10.0 covers:

When you create a new company in SAP Business One you pick the localization, and it cannot be switched later. A German entity should therefore be created on the Germany localization from day one. A company that started on another localization and later needs German reporting usually means a new company database and a data migration, not a setting.

When do German companies have to issue e-invoices?

The obligation comes from the Growth Opportunities Act (Wachstumschancengesetz) and is explained in the BMF FAQ and the BMF letter of 15 October 2025. For domestic B2B invoices:

1. Since 1 January 2025: every domestic business must be able to receive e-invoices. An e-mail mailbox is enough.
2. Until 31 December 2026: senders may still issue other invoices (paper, or PDF with the recipient’s consent).
3. Until 31 December 2027: senders whose prior-year turnover was up to EUR 800,000 may still issue other invoices.
4. After that: domestic B2B invoices must be e-invoices.

An e-invoice here means a structured format that follows the European standard EN 16931. The two formats named most often are XRechnung, a pure XML file, and ZUGFeRD / Factur-X, a PDF/A-3 with the XML embedded, so people can read it and software can process it. Germany does not prescribe a transmission network for B2B: e-mail works, and Peppol is optional for B2B while widely used for invoices to public authorities (B2G).

This differs from the clearance models I have implemented in other countries, such as Guatemala or El Salvador, where every invoice goes to the tax authority before or right after it is issued. Germany has no central platform for B2B invoices yet; the invoice goes from seller to buyer.

What this means inside SAP Business One

The receiving side is often underestimated. Since 2025 your accounts payable team receives XML files and hybrid PDFs. Someone has to check them and post them as A/P invoices (OPCH), ideally without retyping. The ZUGFeRD guide for the German localization is the starting point; companies with high invoice volumes usually add an inbound document tool on top.

On the sending side, the data must be complete before the e-invoice can be valid. In practice the gaps are in master data, not in the XML: missing VAT IDs on business partners (OCRD.LicTradNum), missing buyer references for public-sector customers (the Leitweg-ID), and wrong tax codes on lines. A query or a validation rule in SAP B1 can find these months before the deadline.

-- SQL Server: German customers with A/R invoices this year but no VAT ID
SELECT DISTINCT T0.CardCode, T0.CardName, T0.LicTradNum
FROM OCRD T0
INNER JOIN OINV T1 ON T1.CardCode = T0.CardCode
INNER JOIN CRD1 T2 ON T2.CardCode = T0.CardCode AND T2.AdresType = 'B'
WHERE T0.CardType = 'C'
  AND T2.Country = 'DE'
  AND T1.DocDate >= '20260101'
  AND (T0.LicTradNum IS NULL OR T0.LicTradNum = '')

-- SAP HANA version
SELECT DISTINCT T0."CardCode", T0."CardName", T0."LicTradNum"
FROM OCRD T0
INNER JOIN OINV T1 ON T1."CardCode" = T0."CardCode"
INNER JOIN CRD1 T2 ON T2."CardCode" = T0."CardCode" AND T2."AdresType" = 'B'
WHERE T0."CardType" = 'C'
  AND T2."Country" = 'DE'
  AND T1."DocDate" >= '20260101'
  AND (T0."LicTradNum" IS NULL OR T0."LicTradNum" = '')

To stop new gaps, a rule in SBO_SP_TransactionNotification can block an A/R invoice for a German customer without a VAT ID. My TransactionNotification guide shows the pattern for both databases. The OCRD table page lists the business partner fields.

To be clear about scope: I do not sell a German e-invoicing connector. The XRechnung and ZUGFeRD functions come from SAP’s localization and from SAP partners in Germany. Where I help is around them: data checks, validation rules, add-ons and integrations.

How does SAP Business One work with DATEV?

Most German companies have a tax advisor (Steuerberater) who works in DATEV. SAP documents a DATEV FI Interface for SAP Business One. The setup in the SAP guide has four parts: check the DATEV tax code assignment, configure business partners, configure G/L accounts (including m:n relationships between SAP and DATEV accounts), and then export a DATEV FI file. The guide has separate sections on special cases for posting documents and for the master data export.

From working with exports like this, three things matter more than the export button:

• Account mapping first. If the SAP B1 chart of accounts does not map cleanly to the DATEV chart (SKR03 or SKR04) your advisor uses, the export works but the advisor corrects postings by hand every month.
• Debtor and creditor numbers. DATEV expects numeric personal accounts. Business partner codes like C20000 need a mapping, and that mapping must not change once exports have started.
• Tax codes. Every SAP tax code that appears on postings needs a DATEV tax key. A missing assignment shows up as postings the advisor cannot book automatically.

What does GoBD mean for an SAP Business One system?

The GoBD are the BMF’s principles for keeping and retaining books and records electronically. Together with § 147 of the Fiscal Code (Abgabenordnung), which gives the tax auditor the right to access accounting data, they set the rules that matter for an ERP:

• Posted documents must not be changed without a trace. SAP B1 posts documents and corrects them with credit memos or cancellation documents, which fits this principle. Custom add-ons must follow the same logic: never update posted document values directly in SQL.
• Data must stay readable and available to the auditor for the full retention period, including after a system change or upgrade.
• E-invoices must be kept in the format received. The XML is the original, not a printout of it.

For custom development this is a design rule. Add-ons I write post through the DI API or the Service Layer, so SAP’s own business rules and change logs apply. Direct writes to SAP tables are not supported by SAP and would also break the GoBD principle of traceability.

Which ERP systems are common in Germany?

The German market for small and mid-size companies is crowded. Systems you meet often include SAP Business One, Microsoft Dynamics 365 Business Central, Sage, DATEV’s own solutions (mainly on the accounting and tax advisor side), Lexware for small companies, and German mid-market ERPs such as abas and proALPHA. Odoo and weclapp appear in cloud-first companies.

There is no best system for everyone. If you are still choosing, compare them on your processes, your tax advisor’s workflow and your e-invoice needs. Our ERP selector is a neutral starting point for that comparison.

What can Kodenova do for SAP Business One users in Germany?

I work remotely, and Pakistan is 3 to 4 hours ahead of Germany depending on daylight saving time, so most of a German working day overlaps with mine. The work I do for SAP B1 companies, in Germany and elsewhere:

• Add-ons inside SAP B1 with the UI API and DI API: production steps, approval screens, scanning, checks. See the add-on development guide.
• Integrations through the Service Layer: web shops, CRM, phone systems, logistics. The Service Layer guide shows the method.
• Portals for staff, customers or suppliers who do not need a full SAP B1 licence.
• Queries, reports and SQL Server to HANA migration of existing queries. See the migration guide.
• AI on top of SAP B1: an MCP server so ChatGPT or Claude can answer questions from live SAP data, with permissions.

The German project behind this page is described in the case study production add-ons, portals and 3CX telephony for SAP B1: caller identification from SAP B1 data when a call comes in, production add-ons for orders, issues and receipts, and web portals for staff outside the SAP client, delivered over 2.5 years.

Kodenova is not an SAP partner and does not resell licences. If you have an SAP partner for licences and support, I work alongside them on development.

Sources

• Bundesministerium der Finanzen: FAQ on the mandatory e-invoice (E-Rechnung)
• Bundesministerium der Finanzen: BMF letter of 15 Oct 2025 on the introduction of the mandatory e-invoice (PDF)
• SAP Help Portal: Localization for Germany, SAP Business One 10.0
• SAP Help Portal: How to Create a XRechnung in the Germany Localization (PDF)
• SAP Help Portal: How to Work with ZUGFeRD Files in the Germany Localization (PDF)
• SAP Help Portal: DATEV FI Interface for SAP Business One
• Abgabenordnung § 147 (retention and data access), gesetze-im-internet.de

Related services

• SAP Business One development
• Web & B2B portals