The Steuer-ID: Germany's eleven-digit constant

The Bundeszentralamt für Steuern — the federal central tax office that administers the number — describes the IdNo as an eleven-digit number containing no encoded personal information, and states its defining property plainly: "It is permanently valid and does not change, for example, if you move house, change your name or change your marital status." One person, one number, for life — the German answer to the identifier sprawl of older systems.

Already lost yours? The BZSt's own list of where it appears: your income tax assessment, your employment tax statement, or the informational letter from the federal central tax office — which beats the re-request queue every time. For new arrivals who have never had one, the next section is the actual process.

Source: Bundeszentralamt für Steuern, the identification number (IdNo), read 30 August 2026.

For a newcomer the IdNo is Anmeldung-driven: register your German address at the municipal office, and the number is generated off that registration and arrives by post — the letter from the BZSt being one of German bureaucracy's famous mail moments. No separate application exists for the standard case; like the Dutch BSN, it is a by-product of registering, which makes the Anmeldung appointment the real bottleneck to chase.

The trap with money attached: until your employer holds your IdNo, payroll withholds at the punitive fallback class — the over-withholding is eventually reconciled, but "eventually" is doing heavy lifting in a first German month with relocation costs. The mitigation is boring and effective: book the Anmeldung before you land where the city allows it, and warn payroll the letter is in the post.

The IdNo threads through the German life this site documents elsewhere: it is the number Kindergeld applications want for each child (our €259-a-month Kindergeld page covers that file), the anchor of the employment-tax machinery that makes German salaried life administratively smooth, and — indirectly — part of why the employment route into Germany is so much more tractable than any alternative: the system is built for people whose paperwork arrives in the designed order.

The order, for a German move: visa route (no retirement route exists — a verified absence; employment and its §11 SGB V-benchmarked insurance rules are the road), then Anmeldung, then the IdNo letter, then payroll and Kindergeld. The Germany hub carries the insurance rules that gate step one, and the checklist holds the sequence.