ED17 - Bundesagentur für Arbeit and BZSt: Company Number, W-IdNr, USt-IdNr

Problem

An organization needs central identifiers from federal authorities - but in the SME sector it is unclear which ones and where they are stored:

"Company number? Payroll software has it." - the SV-Betriebsnummer (BA) is in the payroll software, but not in the repo - if the account is canceled, it is gone
W-IdNr unknown - the Wirtschafts-Identifikationsnummer (BZSt) is new and unknown to many entrepreneurs
USt-IdNr confused with tax number - the VAT identification number (EU) is not the same as the tax number (FA) - but the two are confused
No central storage - identifiers are in various documents, mailboxes, software instances - nowhere central
No sidecars - the notifications are available as PDF, but without SHA-256 and without sidecar - not verifiable

Key Statement

Central identifiers in the Git repo mean:

All identifiers in registry/ with sidecar - central storage, SHA-256 + V7GUID:uuidV7 per document
Betriebsnummer (BA) - SV-Betriebsnummer for social insurance reports
W-IdNr (BZSt) - Wirtschafts-Identifikationsnummer for tax purposes
USt-IdNr (BZSt) - VAT identification number for EU-wide transactions
Authority Identifier Registry - a central location that bundles all identifiers

Compliance by Design: Identifiers are not managed decentrally in software instances, but centrally in the repo with sidecars - independent of cloud accounts and software licenses.

The Three Central Identifiers

%%{init: {'theme':'base','themeVariables':{'primaryColor':'#FBFAF7','primaryTextColor':'#0F1B33','primaryBorderColor':'#6B7280','lineColor':'#6B7280'}}}%% flowchart TD O["Organisation ORG-1"] O --> BA["Bundesagentur für Arbeit"] O --> BZ["Bundeszentralamt für Steuern"] BA --> BN["SV-Betriebsnummer"] BZ --> WI["W-IdNr"] BZ --> UI["USt-IdNr"] BN --> VN["Verwendung: SV-Meldungen (DEÜV)"] WI --> VW["Verwendung: steuerliche Zwecke"] UI --> VU["Verwendung: EU-weite Rechnungen"] style O fill:#0F1B33,stroke:#0F1B33,color:#FBFAF7 style BA fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style BZ fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style BN fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style WI fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style UI fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style VN fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style VW fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style VU fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33

Identifier	Authority	Use	Storage in repo
SV-Betriebsnummer	Bundesagentur für Arbeit (BA-Service)	SV reports (DEÜV), payroll accounting	`registry/arbeitsagentur/` + sidecar
W-IdNr	Bundeszentralamt für Steuern (BZSt)	Tax identification (new)	`registry/bzst/` + sidecar
USt-IdNr	Bundeszentralamt für Steuern (BZSt)	EU-wide VAT identification	`registry/bzst/` + sidecar

Important - distinction: The Steuernummer (FA, see ED14) is for domestic tax returns. The USt-IdNr (BZSt) is for EU-wide invoices. The W-IdNr (BZSt) is the new Wirtschafts-Identifikationsnummer. All three are different numbers - but all are stored centrally in registry/ with sidecar.

SV-Betriebsnummer (Bundesagentur für Arbeit)

%%{init: {'theme':'base','themeVariables':{'primaryColor':'#FBFAF7','primaryTextColor':'#0F1B33','primaryBorderColor':'#6B7280','lineColor':'#6B7280'}}}%% flowchart LR A["Antrag bei BA-Service"] A --> B["SV-Betriebsnummer erteilt"] B --> R["registry/arbeitsagentur/"] R --> S["Beleg + Sidecar"] S --> U["Verwendung: DEÜV, Lohnabrechnung"] style A fill:#FDBA74,stroke:#C2410C,color:#0F1B33 style B fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style R fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style S fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style U fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33

Property	Value
Authority	Bundesagentur für Arbeit, BA-Service Saarbrücken
Format	8-digit number (e.g. `<SV-BETRNR>`)
Use	SV reports (DEÜV), payroll accounting, SV contribution statement
Storage	`registry/arbeitsagentur/` with sidecar (SHA-256 + `V7GUID:uuidV7`)
Document	BA notification (PDF) with sidecar

Practical example: The KMU received the SV-Betriebsnummer <SV-BETRNR> on 260706. The BA notification is stored as a document with sidecar in registry/arbeitsagentur/. The number is used in payroll accounting (ED23) and in DEÜV reports (ED22).

W-IdNr and USt-IdNr (Bundeszentralamt für Steuern)

%%{init: {'theme':'base','themeVariables':{'primaryColor':'#FBFAF7','primaryTextColor':'#0F1B33','primaryBorderColor':'#6B7280','lineColor':'#6B7280'}}}%% flowchart LR B["BZSt"] B --> W["W-IdNr"] B --> U["USt-IdNr"] W --> WV["Wirtschafts-Identifikationsnummer"] W --> WD["Format: DE-"] W --> WU["Verwendung: steuerliche Zwecke"] U --> UV["USt-Identifikationsnummer"] U --> UD["Format: DE"] U --> UU["Verwendung: EU-weite Rechnungen"] style B fill:#0F1B33,stroke:#0F1B33,color:#FBFAF7 style W fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style U fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style WV fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style WD fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style WU fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style UV fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style UD fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style UU fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33

Identifier	Format	Use	Storage
W-IdNr	`DE<NNNNNNNNN>-<NNNNN>`	Business identification (new, tax-related)	`registry/bzst/` + sidecar
USt-IdNr	`DE<NNNNNNNNN>`	EU-wide VAT identification	`registry/bzst/` + sidecar

Practical example: The KMU received the W-IdNr DE<WID>-<NNNNN> on 260528 and the USt-IdNr DE<UID> on 260728. Both notifications are stored as documents with sidecar in registry/bzst/.

Authority Identifier Registry (Overall Overview)

%%{init: {'theme':'base','themeVariables':{'primaryColor':'#FBFAF7','primaryTextColor':'#0F1B33','primaryBorderColor':'#6B7280','lineColor':'#6B7280'}}}%% flowchart LR R["registry/"] R --> FA["Finanzamt"] R --> BA["Arbeitsagentur"] R --> BZ["BZSt"] R --> VB["VBG"] R --> KK["Krankenkasse"] R --> EL["ELSTER"] FA --> F1["KSt-StNr"] FA --> F2["USt-StNr"] FA --> F3["LSt-StNr"] FA --> F4["§ 60a AO Bescheid"] BA --> B1["SV-Betriebsnummer"] BZ --> Z1["W-IdNr"] BZ --> Z2["USt-IdNr"] VB --> V1["VBG-Mitgliedsnr"] KK --> K1["IK-Nummer"] EL --> E1["ELSTER-Zertifikat"] style R fill:#0F1B33,stroke:#0F1B33,color:#FBFAF7 style FA fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style BA fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style BZ fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style VB fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style KK fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style EL fill:#DBEAFE,stroke:#1D4ED8,color:#0F1B33 style F1 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style F2 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style F3 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style F4 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style B1 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style Z1 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style Z2 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style V1 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style K1 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33 style E1 fill:#D1FAE5,stroke:#0A7F5C,color:#0F1B33

Authority	Identifier	Directory	Document with sidecar
Tax office	KSt/USt/LSt-StNr, § 60a AO notice	`registry/finanzamt/`	✅
Arbeitsagentur	SV-Betriebsnummer	`registry/arbeitsagentur/`	✅
BZSt	W-IdNr, USt-IdNr	`registry/bzst/`	✅
VBG	VBG membership number	`registry/vbg/`	✅
Health insurance fund	IK number (information identifier)	`registry/krankenkasse/`	✅
ELSTER	Certificate proof	`registry/elster/`	✅

Central insight: All authority identifiers are stored in one place (registry/) with sidecars - not distributed across software instances, cloud accounts, or paper folders. During an external audit, the auditor can read all identifiers from the repo - offline, without IAM, without a cloud account.

Risk Leverage

Today (cheap)	Tomorrow (audit-proof)	Risk mitigated
SV-Betriebsnummer in `registry/` with sidecar	Number centrally verifiable	Loss upon cloud cancellation
W-IdNr in `registry/` with sidecar	Business identification verifiable	Dispute of identity
USt-IdNr in `registry/` with sidecar	EU identification verifiable	Non-deductibility of input tax (EU)
Authority Identifier Registry	All numbers centrally in one place	Decentralized management (loss)
Sidecar per document	Every notification cryptographically anchored	Dispute of authenticity

Harness Requirement (Preview)

Derivable from ED17:

ID	Requirement	Priority
FA-12.8	Authority Identifier Registry (StNr, W-IdNr, USt-IdNr, SV-BetrNr, VBG membership no., IK)	MUST
FA-2.1	SHA-256 as cryptographic integrity check; DocID is the `uuidV7` alone	MUST
FA-2.2	`.gc.md` sidecar mandatory per document/artifact	MUST

The complete requirements list is in Harness-Anforderungen.md.

Sources

SGB IV (§ 28i - company number, § 28a - DEÜV reports)
AO (§ 139a - tax identification number, § 139c - W-IdNr)
UStG (§ 27a - USt-IdNr)
E1/agents/ (anonymized) - SSoT concept with registry, sidecars

Source Topology and CDN Reference Links

Role	Location	Purpose
Primary / SSoT	git.gitcover.org/GCC	Canonical storage (GPG-signed, versioned)
Public OSS Mirror / CDN	codeberg.org/gitcover-commons	Read-only mirror; FLOSS discovery
Community Hub	github.com/gitcover-commons	Issues & Discussions; source code reference on Codeberg

Note: This assignment of sources, mirror, and community hub reflects the current state and may change. Please check the respective canonical source on gitcover.org for the current state.