ED17 - Federal Employment Agency and BZSt: Company Number, W-IdNr, USt-IdNr

Problem

An organization needs central identifiers from federal agencies - but in the SME sector, it is unclear which and where they are located:

"Company number? The payroll software has it." - The social security company number (BA) is in the payroll software, but not in the repo - if the account is canceled, it is gone
W-IdNr unknown - The economic identification number (BZSt) is new and unknown to many business owners
USt-IdNr confused with tax number - The VAT identification number (EU) is not the same as the tax number (FA) - but the two are conflated
No central repository - Identifiers are in various documents, mailboxes, software instances - nowhere are they centralized
No sidecars - The notifications are available as PDFs, but without SHA-256 and without a sidecar - not verifiable

Core Statement

Central identifiers in the Git repo mean:

All identifiers in registry/ with sidecars - central storage, SHA-256 + V7GUID:uuidV7 per evidence document
Company number (BA) - social security company number for social security reports
W-IdNr (BZSt) - economic identification number for tax purposes
USt-IdNr (BZSt) - VAT identification number for EU-wide transactions
Authority identifier registry - a central location that brings together all identifiers

Compliance by Design: Identifiers are not managed in a decentralized manner 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["Organization ORG-1"] O --> BA["Federal Employment Agency"] O --> BZ["Federal Central Office for Taxes"] BA --> BN["Social Security Company Number"] BZ --> WI["W-IdNr"] BZ --> UI["USt-IdNr"] BN --> VN["Use: Social Security Reports (DEÜV)"] WI --> VW["Use: Tax Purposes"] UI --> VU["Use: EU-Wide Invoices"] 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 Repository
Social Security Company Number	Federal Employment Agency (BA Service)	Social security reports (DEÜV), payroll	`registry/arbeitsagentur/` + sidecar
W-IdNr	Federal Central Office for Taxes (BZSt)	Tax identification (new)	`registry/bzst/` + sidecar
USt-IdNr	Federal Central Office for Taxes (BZSt)	EU-wide VAT identification	`registry/bzst/` + sidecar

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

%%{init: {'theme':'base','themeVariables':{'primaryColor':'#FBFAF7','primaryTextColor':'#0F1B33','primaryBorderColor':'#6B7280','lineColor':'#6B7280'}}}%% flowchart LR A["Application to BA Service"] A --> B["Social Security Company Number Granted"] B --> R["registry/arbeitsagentur/"] R --> S["Evidence Document + Sidecar"] S --> U["Use: DEÜV, Payroll"] 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	Social security reports (DEÜV), payroll, social security contribution certificate
Storage	`registry/arbeitsagentur/` with sidecar (SHA-256 + `V7GUID:uuidV7`)
Evidence document	BA notification (PDF) with sidecar

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

W-IdNr and USt-IdNr (Federal Central Office for Taxes)

%%{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["Economic Identification Number"] W --> WD["Format: DE-"] W --> WU["Use: Tax Purposes"] U --> UV["VAT Identification Number"] U --> UD["Format: DE"] U --> UU["Use: EU-Wide Invoices"] 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>`	Economic identification (new, for tax purposes)	`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 evidence documents with sidecars in registry/bzst/.

Authority Identifier Registry (Overall View)

%%{init: {'theme':'base','themeVariables':{'primaryColor':'#FBFAF7','primaryTextColor':'#0F1B33','primaryBorderColor':'#6B7280','lineColor':'#6B7280'}}}%% flowchart LR R["registry/"] R --> FA["Tax Office"] R --> BA["Employment Agency"] R --> BZ["BZSt"] R --> VB["VBG"] R --> KK["Health Insurance Fund"] R --> EL["ELSTER"] FA --> F1["KSt-StNr"] FA --> F2["USt-StNr"] FA --> F3["LSt-StNr"] FA --> F4["§ 60a AO Notice"] BA --> B1["Social Security Company Number"] BZ --> Z1["W-IdNr"] BZ --> Z2["USt-IdNr"] VB --> V1["VBG Membership Number"] KK --> K1["IK Number"] EL --> E1["ELSTER Certificate"] 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	Evidence Document with Sidecar
Tax Office	KSt/USt/LSt-StNr, § 60a AO notice	`registry/finanzamt/`	✅
Employment Agency	Social security 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 proof	`registry/elster/`	✅

Central overview: All authority identifiers are located in one place (registry/) with sidecars - not distributed across software instances, cloud accounts, or filing cabinets. During an external audit, the auditor can read all identifiers from the repo

offline, without IAM, without a cloud account.

Risk Leverage

Today (low-cost)	Tomorrow (revision-proof)	Risk Mitigated
SV company number in `registry/` with sidecar	Number centrally verifiable	Loss upon cloud cancellation
W-IdNr in `registry/` with sidecar	Economic identification verifiable	Identity being disputed
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 evidence document	Every notification cryptographically anchored	Authenticity being disputed

Harness Requirement (Preview)

Derived from ED17:

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 a cryptographic integrity check; DocID consists solely of the `uuidV7`	MUST
FA-2.2	Mandatory `.v7g.md` sidecar per evidence document/artifact	MUST

The complete list of requirements 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 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.