Tax return redaction is the removal of taxpayer data from a self-assessment filing. A return is made under a notice HMRC gives under TMA 1970 s.8. CRCA 2005 s.18 bars Revenue and Customs officials from disclosing information they hold, and s.19 makes wrongful disclosure of identifying information an offence. Those duties bind officials, not you. anonym.plus marks each identifier on your device, so the form reads cleanly while protected data goes.
When this applies
An SA100 states the filer's National Insurance number, UTR, address, and income on the first pages. TMA 1970 s.12B requires the underlying records to be kept — for a business, until the fifth anniversary of the 31 January following the year of assessment. You strip the identifiers from the copy you share, and the retained records stay intact.
How anonym.plus handles it
- Open the filing in anonym.plus on your device.
- Built-in OCR reads a scanned or printed copy.
- The app marks the NI number, UTR, name, and address.
- Confirm each marking and keep the line totals.
- Mask the NI number or swap it for a label.
- Save the clean copy locally.
What you need to provide
- The filing (PDF, scan, or DOCX).
- An operator: Mask keeps only the suffix of an NI number.
- Optional allow-list for the tax year you must cite.
PII & financial identifiers detected
| Category | anonym.plus entity type | Example |
|---|---|---|
| Identifiers | UK_NINO | QQ 12 34 56 C → QQ XX XX XX C |
| Tax reference | NATIONAL_ID | UTR 10 digits → [UTR] |
| Names | PERSON | filer Daniel Rowe → [TAXPAYER] |
| Location | LOCATION | 44 Elm Street, Bath → [ADDRESS] |
| Money | MONEY | repayment £2,310 → [AMOUNT] |
| Dates | DATE_TIME | date of birth 1979 → [DOB] |
Compliance achieved
- Reflects the confidentiality duty on officials in CRCA 2005 s.18, and the wrongful-disclosure offence in CRCA 2005 s.19.
- Leaves the records TMA 1970 s.12B requires you to keep untouched — redaction applies only to the copy you share.
- Keeps a return readable for an enquiry under TMA 1970 s.9A, and does not affect an information notice under Finance Act 2008 Sch. 36.
- DPA 2018 Sch. 2 Pt. 1 para. 2 restricts some data-protection rights where data is processed for the assessment or collection of tax; redaction still lowers onward exposure. Runs offline, so protected data reaches no server.
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Limitations & cautions
Section 18 binds officials, not the agent or the taxpayer who shares a copy. A unique figure on a supplementary page can still point to one filer. The app marks named items; a rare relief or a single large source of income may hint at a person. Review the supplementary pages before you share.
Frequently asked questions
What does CRCA 2005 s.18 actually protect?
It bars Revenue and Customs officials from disclosing information held in connection with an HMRC function, and s.19 makes wrongful disclosure of identifying information a criminal offence. The duty sits on officials. anonym.plus marks the same identifiers so a copy you share carries similar care.
How much of the NI number may stay?
Often only the final letter, depending on the recipient. The Mask operator keeps the suffix and hides the digits in one pass.
Does redacting a copy affect my record-keeping duty?
No. TMA 1970 s.12B sets how long the underlying records must be kept, and a redacted working copy is separate from them. Keep the originals for the statutory period, because an enquiry under s.9A or a notice under Finance Act 2008 Sch. 36 may still reach them.