An e-invoice is only correct if it satisfies the rules both technically and in substance. Validation runs in two stages: first the XML is checked against the schema of its syntax (UBL or CII), then against the business rules expressed as Schematron. For XRechnung, KoSIT publishes an official validator and the matching rule sets, which invoice portals and many accounting programs also use.
The rules are grouped by prefix. BR rules come from EN 16931 and cover mandatory fields, BR-CO rules check calculations and dependencies, for example whether totals and tax amounts add up. Rules such as BR-S or BR-AE apply to individual VAT categories, and BR-DE rules are the national additions of XRechnung. An error message names the rule, the affected field and an XPath, but the real cause often sits elsewhere, such as a line amount that was rounded incorrectly.
In this category we explain the most common error messages in plain language, show the cause in the XML and how to fix the error for good, in the invoicing software rather than only in a single file. Look up any rule with its fix in the KoSIT error hub, and validate your file for free with the XRechnung viewer, right in your browser, without the file ever leaving your computer.
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7 min readRead How to Fix the 10 Most Common XRechnung Validation Errors
Fix XRechnung validation errors fast: the 10 most common KoSIT error messages with cause, affected field and XPath, plus what to do when your invoice is rejected.
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