What is the difference between my German tax number and my VAT number, and which one does Amazon want?

Germany issues two numbers from two authorities. The tax number (Steuernummer, in the form 26/123/45678) comes first, from your tax office (Finanzamt). Your German VAT is owed from the start of your activity in Germany, not from that day; the returns for every period since then are filed once the tax number arrives. The VAT number (USt-IdNr, "DE" plus nine digits) comes by post from the federal office (Bundeszentralamt für Steuern, BZSt), often together with the tax number, otherwise usually a few weeks later. Amazon and the other marketplaces accept only the VAT number; the tax number is rejected there. We tell you the day each one arrives. A number ending in "-00001" is a third one, the business identification number (Wirtschafts-Identifikationsnummer), and works on neither form.