# Partner Attestation — DONNA Compliance Use

**Matter**: ZEN-041 — *Zenith Holdings plc / acquisition of NimbusLogistics Group Ltd*
**Reporting period**: 14 April 2026 (matter inception) to 28 April 2026 (FCA response date)
**Firm**: Sterling & Co. LLP
**Annex of**: Engagement Letter dated 14 April 2026 (annex C)
**Firm AI Policy**: v3.2 (March 2026)

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## Attestation

I, **Catherine Marlowe**, Partner of Sterling & Co. LLP, supervising partner for matter ZEN-041, attest the following:

### 1. AI tooling used

DONNA (donnaoss.com; AGPL-3.0; self-hosted) has been used on this matter for: voice-captured time entries; intra-team task delegation routing; first-draft generation of working documents; and the firm's IDR (Intent Decision Record) audit chain.

### 2. Self-hosting confirmed

DONNA is run on Sterling & Co.'s on-premises GPU cluster (Holborn datacentre, rack DC-7-12). The model invocation endpoint is at `https://donna.internal.sterlingco.example/v1/decide` — a Sterling & Co.-controlled URL inside the firm's network perimeter. **No client material has been transmitted to any third-party AI service at any point during this matter.**

### 3. Network egress controls verified

Network egress from the matter VLAN to external AI providers is blocked at the firm's network boundary. The control is independently audited annually under ISO/IEC 27001:2022. The most recent surveillance audit (March 2026) confirmed the egress controls are operating as designed. The auditors' report is held by the firm's General Counsel.

### 4. PII anonymisation verified

Every model invocation under this matter has passed through DONNA's PII anonymisation pre-processor. Real client names, matter names, person names, and counterparty names are replaced with opaque identifiers (`CLIENT_42`, `ZEN-041`, `s.odonnell`, etc.) before any model invocation. De-anonymisation occurs only inside the firm's encrypted matter store. Verification: spot-check of 10 model invocations on this matter (recorded as `idr_001`, `idr_003`, `idr_005`, `idr_007`, `idr_009b`, `idr_011`, `idr_017`, `idr_023`, `idr_031`, `idr_044`) confirmed no real client name appeared in any model prompt.

### 5. IDR audit chain integrity confirmed

The IDR audit chain for this matter (47 records as at the reporting date) has been verified end-to-end using `bin/notarise verify --chain audit/zen-041-chain.json --key sterling-co-key-2026`. The verifier returned `OK: 47 record(s) verified (HMAC-SHA256)`. Verification timestamp: 28 April 2026 09:14 UTC. Chain integrity: intact.

### 6. SRA, EU AI Act, and firm-policy compliance

The use of DONNA on this matter has been carried out in compliance with:

a) the Solicitors Regulation Authority's *AI in Legal Services* guidance (October 2025);
b) the high-risk obligations of the EU AI Act (Regulation (EU) 2024/1689), to the extent that those obligations bind from 2 August 2026 — the firm has elected to comply ahead of the binding date;
c) the firm's internal AI Policy v3.2 (March 2026); and
d) the deliberate architectural reading of *Munir v Secretary of State for the Home Department* [2026] UKUT 81 at [37]–[41] adopted by the firm: that the *Munir* category of *"closed-source AI tools which do not place information in the public domain"* is the only category of AI tooling permitted on client matters.

### 7. Privilege preserved

Communications between Sterling & Co. and Zenith in connection with the matter remain subject to legal advice privilege under English law. The use of DONNA preserves privilege because no client material has been disclosed to any third party (including any AI service provider) at any point. The audit chain records, for each model invocation, the model identifier, the prompt scope, and the output destination — all internal to the firm.

### 8. Falsification commitment

Should any of the foregoing prove to be inaccurate in any material respect, this attestation is to be treated as withdrawn from the date of discovery, the matter is to be re-attested by the firm's General Counsel, and the FCA is to be notified within 7 Business Days. The firm undertakes to maintain a falsification register at `/firm-fs/compliance/attestations-falsification-register.csv`, available on request.

---

**Signed**

________________________________
**Catherine Marlowe**
*Partner, Corporate & M&A*
Sterling & Co. LLP
SRA No. 442178 / Individual SRA No. 488912

Date: 28 April 2026

**Witnessed (countersigned)**:

________________________________
**Geoffrey Templar**
*General Counsel*
Sterling & Co. LLP

Date: 28 April 2026

---

## Audit chain reference

The full IDR Audit Chain for this matter is at: `/firm-fs/matters/ZEN-041/audit/zen-041-chain.json` (firm-internal); a regulator-formatted export is at Annex A of the FCA Response Letter dated 28 April 2026.

Independent verification command (any party with the chain file and the firm's public key fingerprint can run this):

```bash
git clone https://github.com/chiefofstaff-legal/donna.git
cd donna
bin/notarise verify --chain /path/to/zen-041-chain.json --key sterling-co-key-2026-fingerprint
```

Expected output: `OK: 47 record(s) verified (HMAC-SHA256)`.

---

> **Demo note**: this attestation is the partner's signed undertaking that DONNA was used in compliance with SRA, EU AI Act, and firm policy. The structure mirrors a regulator-grade attestation — falsification commitment included. The auditor (or the FCA, or opposing counsel under disclosure) can verify the chain *without trusting Sterling & Co.'s software*: the verifier is open-source, the chain is self-contained, the signature scheme is HMAC-SHA256. *Donna probat.*