Tax workpaper redaction is the removal of taxpayer data from a preparation file. Confidentiality here is contractual and professional, not privileged. In Prudential plc v Special Commissioner of Income Tax [2013] UKSC 1 the Supreme Court held that legal advice privilege does not extend to advice from an accountant. anonym.plus marks each identifier on your device, so the computation trail stays while protected data goes.
When this applies
A prep workpaper carries the client's NI number, prior-year figures, and source documents. HMRC can require documents by information notice under Finance Act 2008 Sch. 36, and Part 4 of that Schedule sets narrow restrictions for auditors' and tax advisers' papers. You strip the identifiers before a reviewer opens the file.
How anonym.plus handles it
- Open the prep file in anonym.plus on your device.
- Built-in OCR reads scanned source documents.
- The app marks the NI number, UTR, name, and address.
- Keep the computation steps and reconciling notes.
- Mask the NI number or swap it for a label.
- Save the clean file locally.
What you need to provide
- The prep file (PDF, XLSX, DOCX, scan).
- An operator: Mask keeps only the suffix of an NI number.
- Optional batch for a folder of source documents.
PII & financial identifiers detected
| Category | anonym.plus entity type | Example |
|---|---|---|
| Identifiers | UK_NINO | QQ 45 21 77 D → QQ XX XX XX D |
| Identifiers | NATIONAL_ID | client UTR → [UTR] |
| Names | PERSON | client Maeve Orr → [TAXPAYER] |
| Location | LOCATION | client address → [ADDRESS] |
| Money | MONEY | total income £112,400 → [AMOUNT] |
| Dates | DATE_TIME | prior yr 2025 → [YEAR] |
Compliance achieved
- Mirrors the confidentiality officials owe under CRCA 2005 s.18 when you share a working copy.
- Notes that Prudential plc v Special Commissioner of Income Tax [2013] UKSC 1 confirms legal advice privilege does not cover advice from an accountant.
- Recognises the restrictions on information notices for auditors and tax advisers in Finance Act 2008 Sch. 36 Pt. 4.
- Leaves the records TMA 1970 s.12B requires, and the enquiry window in TMA 1970 s.9A, untouched. Runs offline with nothing uploaded.
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Limitations & cautions
Redaction is not privilege. Prudential [2013] UKSC 1 means an accountant's advice is not protected the way a solicitor's is, and Finance Act 2008 Sch. 36 Pt. 4 sets narrow limits rather than a blanket shield. A unique prior-year amount can still hint at a client. Scan the computation notes before you share.
Frequently asked questions
What counts as protected data in a prep file?
The client's identity, the figures, and anything sourced from HMRC. CRCA 2005 s.18 binds officials who hold the same data, so anonym.plus marks those identifiers to let a copy you share carry similar care.
Are an accountant's workpapers privileged?
Not in the way a solicitor's advice is. In Prudential [2013] UKSC 1 the Supreme Court held legal advice privilege does not extend to accountants. Finance Act 2008 Sch. 36 Pt. 4 gives limited protection for auditors' and advisers' papers, and it is narrow.
Can I keep the computation steps?
Yes. Allow-list the computation columns. Only personal identifiers, not the logic, are marked, so a reviewer can still follow the workings.