NormAPI Reviews & Product Details

NormAPI is an e-invoicing API for Germany's XRechnung and ZUGFeRD formats. The validator is free, needs no sign-up and stores nothing: upload an invoice (UBL, CII or ZUGFeRD PDF) and every finding comes back with its official rule code and where it occurs in the XML. Every business-rule finding also gets a plain-language explanation of its cause and how to fix it, in English or German. Checks run against the current KoSIT rule set, and the version is stated on every result. For software teams, the same checks are available as a REST API, together with generation of XRechnung (UBL and CII) and ZUGFeRD PDFs from JSON. Every generated invoice is validated before it leaves the API, and rule-set updates are included: KoSIT publishes a new version roughly every six months, and integrations keep working unchanged. An OpenAPI spec, a Postman collection, a TypeScript client on npm and an MCP server for AI agents are available. Built for companies issuing e-invoices under the German mandate, and for the software vendors who generate them for their customers.