German VAT ID (USt-IdNr.)

The USt-IdNr. is not the Steuernummer. The Federal Central Tax Office (BZSt) describes it as a separate number, granted in addition to the tax number. A Steuernummer on an invoice is not something you can check here or in VIES.

After the prefix DE come nine digits. The BZSt also runs its own procedure for German businesses to confirm foreign VAT IDs.