ED13 - Federal Employment Agency 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 located:

"Company number? The payroll software has it." - the SV company number (BA) is stored in the payroll software, but not in the repo - if the account is cancelled, it is gone
W-IdNr unknown - the business identification number (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 both are confused
No central storage - identifiers are located in various documents, mailboxes, software instances - nowhere central
No sidecars - the notifications are available as PDFs, but without SHA-256 and without a sidecar - not verifiable

Key Message

Central identifiers in the Git repo mean:

All identifiers in registry/ with sidecar - central storage, SHA-256 + V7GUID:uuidV7 per document
Company number (BA) - SV company number for social insurance notifications
W-IdNr (BZSt) - business identification number for tax purposes
USt-IdNr (BZSt) - VAT identification number for EU-wide business
Authority identifier registry - a central place 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 the Repo
SV company number	Federal Employment Agency (BA-Service)	SV notifications (DEÜV), payroll accounting	`registry/arbeitsagentur/` + sidecar
W-IdNr	Federal Central Tax Office (BZSt)	Tax identification (new)	`registry/bzst/` + sidecar
USt-IdNr	Federal Central Tax Office (BZSt)	EU-wide VAT identification	`registry/bzst/` + sidecar

Important - Distinction: The tax number (FA, see ED11) is for domestic tax returns. The USt-IdNr (BZSt) is for EU-wide invoices. The W-IdNr (BZSt) is the new business identification number. All three are different numbers - but all are stored centrally in registry/ with a sidecar.

SV Company Number (Federal Employment Agency)

%%{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	Federal Employment Agency, BA-Service Saarbrücken
Format	8-digit number (e.g. `<SV-BETRNR>`)
Use	SV notifications (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 company number <SV-BETRNR> on 260706. The BA notification is stored as a document with sidecar in registry/arbeitsagentur/. The number is used in payroll accounting (ED14) and for DEÜV notifications (ED15).

W-IdNr and USt-IdNr (Federal Central Tax Office)

%%{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 sidecars in registry/bzst/.

Authority Identifier Registry (Complete 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/`	✅
Employment agency	SV company number	`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 record	`registry/elster/`	✅

Key Insight: All authority identifiers are located in one place (registry/) with sidecars - not scattered 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 company number in `registry/` with sidecar	Number centrally verifiable	Loss upon cloud account cancellation
W-IdNr in `registry/` with sidecar	Business identification verifiable	Denial of identity
USt-IdNr in `registry/` with sidecar	EU identification verifiable	Non-deductibility of input VAT (EU)
Authority identifier registry	All numbers centrally in one place	Decentralized management (loss)
Sidecar per document	Every notification cryptographically anchored	Denial of authenticity

Harness Requirement (Preview)

Derivable from ED13:

ID	Requirement	Priority
FA-12.8	Authority identifier registry (StNr, W-IdNr, USt-IdNr, SV-BetrNr, VBG-Mitgliedsnr, IK)	MUST
FA-2.1	SHA-256 as cryptographic integrity check; DocID is the `uuidV7` alone	MUST
FA-2.2	`.v7g.md` sidecar mandatory per document/artifact	MUST

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

Sources

SGB IV (§ 28i - company number, § 28a - DEÜV notifications)
AO (§ 139a - tax identification number, § 139c - W-IdNr)
UStG (§ 27a - USt-IdNr)
AFJD/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 mapping 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 status.