Editorial policy & methodology
The guides, templates and calculators from Solobuch help self-employed people issue compliant invoices. This page explains how the content is made and what you can rely on.
Who writes
Tax and legal articles are published under "Redaktion Solobuch". Technical articles on XRechnung, ZUGFeRD, Leitweg-ID and validation are written by the founder and developer Serhii Makarov, who builds the corresponding features himself.
Sources we rely on
- Laws and regulations: the German VAT Act (UStG) and its implementing ordinance (UStDV).
- Administrative guidance: letters of the Federal Ministry of Finance (BMF), especially on e-invoicing and the VAT application decree.
- Technical standards: European standard EN 16931, the XRechnung standard and the ZUGFeRD/Factur-X specification.
- Primary sources are named in the article; we link to the original where it is publicly available.
Review and "last updated" date
Every article shows a "Stand" (last updated) date. When the law or the technology changes, we update the text and the date. Statements on deadlines, amounts and obligations are checked against the sources above before publication.
Not tax advice
Our content is general information, not tax or legal advice. For your individual case, please consult a tax advisor.
Report an error
Found a mistake or outdated information? Write to [email protected] with the link to the page. We review every report and correct what is wrong.