German employer registrations and IDs: Betriebsnummer, Unternehmensnummer, ELStAM and ELSTER

Start with the Berufsgenossenschaft — not the Bundesagentur

Most setup guides begin with the Betriebsnummer. The statute begins somewhere else: within one week of the start of the enterprise, the Unternehmer must notify the competent accident-insurance carrier (Unfallversicherungsträger — for most businesses, a Berufsgenossenschaft) of the nature and object of the enterprise, the number of insured persons and the opening day (§ 192 Abs. 1 SGB VII). A trade notification under §§ 14/55c Gewerbeordnung filed within the week satisfies the duty.

That notification is what produces the first identifier. Since 1 January 2023, every Unternehmer carries a Unternehmensnummer (UNR.S) — statutory accident insurance's uniform identifier under § 136a SGB VII. It has 15 digits: the first 12 identify the Unternehmer (the Unternehmernummer), the last 3 the specific enterprise. The DGUV puts the trigger plainly: „Sie erhalten die Unternehmensnummer für Ihr neues Unternehmen, sobald ein Unfallversicherungsträger hierüber Kenntnis erlangt." — "You receive the Unternehmensnummer for your new enterprise as soon as an accident-insurance carrier learns of it" (our translation).

Why the sequencing matters: the Betriebsnummer application itself asks for it. § 18i Abs. 2 SGB IV lists the data the employer must transmit to the Bundesagentur für Arbeit — name and address of the Beschäftigungsbetrieb, place of employment, economic activity, legal form „sowie die Unternehmernummer einschließlich des Anhangs gemäß § 136a des Siebten Buches" — "as well as the Unternehmernummer including its suffix per § 136a SGB VII" (our translation). The accident-insurance registration logically precedes the employment-agency one.

The Betriebsnummer: the employer key on the social-insurance rail

To take part in the social-insurance reporting procedures at all, the employer must electronically apply for a Betriebsnummer for each of its Beschäftigungsbetriebe at the Bundesagentur für Arbeit (§ 18i Abs. 1 SGB IV). The application runs online through the BA's Betriebsnummern-Service. In its published principles (Stand 21 December 2022), the BA describes the number's job: „Damit ist die Betriebsnummer ein elementares Merkmal im Meldeverfahren zur Sozialversicherung." — "the Betriebsnummer is thus an elementary attribute of the social-insurance reporting procedure" (our translation): it is how employers are uniquely identified with the insurance carriers and how contribution payments are allocated to the right employer account.

Three mechanics to plan around:

• It's per establishment, not per company. Separate Betriebsnummern must be assigned for Beschäftigungsbetriebe of the same employer with different economic activities or in different municipalities (§ 18i Abs. 3 SGB IV). A company with offices in two cities runs two Betriebsnummern.
• The trigger is having reports to file. Per the BA's decision schema (Stand 12 July 2022), a Betriebsnummer is needed exactly when the employer has social-insurance Meldungen to submit — an "Arbeitgeber" for this purpose being any natural or legal person or partnership with at least one person in insurable or marginal employment.
• It rides on everything. Every DEÜV report carries the Betriebsnummer of the Beschäftigungsbetrieb alongside the employee's Versicherungsnummer, the contribution groups and the competent Einzugsstelle (§ 28a Abs. 3 SGB IV) — and the first of those reports, the Anmeldung for each new hire, is due with the first payroll run, at latest six weeks after commencement (§ 6 DEÜV).

The tax side: Finanzamt, Steuernummer and ELStAM

Whoever opens a business or a Betriebsstätte must notify it — via the municipality, which informs the competent Finanzamt (§ 138 Abs. 1 AO) — and must additionally supply further tax-relevant particulars electronically, by official data set over the official interface (§ 138 Abs. 1b AO). In practice this electronic questionnaire is known as the Fragebogen zur steuerlichen Erfassung, lodged via ELSTER — the name is the practice term, not the statute's.

What that registration yields for payroll is the Steuernummer of the lohnsteuerliche Betriebsstätte — the establishment where the relevant wage is calculated (§ 41 Abs. 2 EStG). The Lohnsteuer-Anmeldung is filed with that establishment's Finanzamt (the Betriebsstättenfinanzamt) by the 10th day after each filing period, electronically by official data set (§ 41a EStG); the period is the calendar month, quarter or year depending on prior-year withholding — monthly above €5,000, quarterly above €1,080 up to €5,000, annually at or below €1,080 (thresholds per the § 41a text in force July 2026). The official 2026 Lohnsteuer-Anmeldung form (BMF Muster, Bekanntmachung of 14 August 2025) carries Steuernummer as its first form field — so the Steuernummer from step 3 is the number your wage-tax filings actually run under.

Then comes ELStAM — the elektronische Lohnsteuerabzugsmerkmale that tell payroll each employee's tax class, allowances and church-tax attributes. At the start of every employment the employer must retrieve the employee's ELStAM from the Bundeszentralamt für Steuern by remote data transfer, authenticating itself, and take them into the Lohnkonto (§ 39e Abs. 4 EStG). The BZSt states the duty directly: „Der Arbeitgeber ist verpflichtet, den Arbeitnehmer bei Aufnahme des Dienstverhältnisses bei der Finanzverwaltung anzumelden und zugleich die ELStAM anzufordern." — "The employer is obliged to register the employee with the tax administration on commencement and at the same time request the ELStAM" (our translation). The retrieval keys are the employee's Steuer-IdNr plus date of birth, the start date — and, on the employer side, the employer's Wirtschafts-Identifikationsnummer. Employer-side questions about retrieval sit with the Betriebsstättenfinanzamt, not the BZSt.

ELSTER: register once, but the certificate type is a choice

ELSTER is the tax administration's electronic channel, and two payroll flows depend on it: the authenticated transmission of the Lohnsteuer-Anmeldung, and the ELStAM retrieval. The 2026 form's own instructions make the first explicit — the Lohnsteuer-Anmeldung must be transmitted authenticated, per official data set by remote data transmission; only on application, to avoid undue hardship, can the Finanzamt allow a signed paper form instead.

For the employer's own access, the prerequisite is registration in Mein ELSTER, which yields an ELSTER certificate. On the certificate type, ELSTER's employer guidance is a recommendation, not a mandate: „Für die Teilnahme am Verfahren ELStAM wird grundsätzlich die Auswahl des Organisationszertifikats empfohlen" — "for participation in the ELStAM procedure, choosing the Organisationszertifikat is generally recommended" (our translation). The Organisationszertifikat is issued against the entity's Steuernummer and supports up to 200 authorisations per Steuernummer — up to 1,000 with a Sicherheitsstick or Signaturkarte — which is why it is the sensible choice for anything beyond a micro-employer; a persönliches Zertifikat also works.

And if someone else runs your payroll transmission? „In diesen Fällen entfällt für Arbeitgeber die Registrierung in Mein ELSTER" — "in these cases the employer's registration in Mein ELSTER is dispensed with" (our translation): an employer whose Steuerberater or payroll provider transmits for it needs no ELSTER registration of its own. One caveat before you skip the certificate entirely: the SV-Meldeportal — the official completion aid on the social-insurance side — requires an ELSTER-Organisationszertifikat for registration and every login, so employers planning to self-serve SV reports without payroll software will need one anyway.

No manual lane: the systemgeprüfte-software duty

On the social-insurance rail there is no paper or web-form fallback for the reports themselves. § 95b SGB IV makes machine transmission the exclusive channel: „Meldepflichtige haben Meldungen und Beitragsnachweise durch Datenübertragung aus systemgeprüften Programmen oder systemgeprüften elektronischen Ausfüllhilfen zu erstatten." — "Parties obliged to report must submit reports and contribution statements by data transmission from system-tested programs or system-tested electronic completion aids" (our translation). Per the DRV's 2026 employer guidance, the underlying facts must be machine-detected and the messages machine-generated — secured, encrypted transmission from systemgeprüfte Entgeltabrechnungsprogramme or via system-tested Ausfüllhilfen, exclusively.

Employers without a system-tested payroll program must use a system-tested completion aid — manual keying only; machine-feeding employer data into an Ausfüllhilfe is not permitted. The official aid is the SV-Meldeportal (§ 95a SGB IV): it creates and transmits Meldungen, Beitragsnachweise and Bescheinigungen with plausibility checks, but expressly computes neither pay nor contributions, and charges a usage fee in advance for 36 months — €36 net for one Betriebsnummer, €99 net for several (fees per the DRV's 2026 guidance). In short: for a real payroll, certified software is not an option but the only lawful channel.

Employers with no German entity

None of the above requires a German legal entity — social insurance follows the employee, not the employer's seat. But a foreign employer without a seat in Germany must appoint a Bevollmächtigter mit Sitz im Inland — an authorised representative in Germany — to meet the payroll-record duties of § 28f Abs. 1b SGB IV, and accident insurance carries a parallel representative requirement of its own (§ 130 Abs. 2 SGB VII, with Berlin deemed the seat if none is appointed). Wage tax works differently again: the withholding obligation generally only attaches once the employer has a German footprint. The full picture — who must register what from abroad, and what a Betriebsstätte changes — is in our guide to running German payroll from overseas.

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