Bank detail redaction is the removal of account data from a wage file. UK GDPR Art. 32(1)(a) names pseudonymisation and encryption as measures appropriate to the risk. A payroll direct-credit file concentrates that risk: one row per worker, each with a sort code and an account number. anonym.plus masks each value on your device, so the record stays usable.
When this applies
A Bacs direct credit runs on a three-day cycle, so the file sits somewhere before it moves. Lose it and you have a personal data breach that Art. 33 puts on a 72-hour clock to the ICO. Art. 34 adds notification to the workers themselves where the risk is high. Payroll diversion fraud, where a spoofed message changes one account number, starts from exactly this data.
How anonym.plus handles it
- Open the file in anonym.plus on your device.
- Local OCR reads a scanned mandate if present.
- The tool flags sort codes, accounts, and IBANs.
- Confirm the flags and keep the bank name if cited.
- Apply Mask to keep only the last four digits.
- Save the clean file locally.
What you need to provide
- The file (CSV, XLSX, PDF, or scan).
- The Mask operator set to keep the last four digits.
- Optional batch for many credit records.
PII entity types detected
| Category | anonym.plus entity type | Example |
|---|---|---|
| Financial | UK_BANK_NUMBER | a/c 12345678 → ****5678 |
| Financial | UK_SORT_CODE | 12-34-56 → [SORT] |
| Financial | IBAN_CODE | GB29 NWBK ... → [IBAN] |
| Names | PERSON | holder Tann → [HOLDER] |
| Identifiers | UK_NINO | linked NI → [NINO] |
| Organization | ORGANIZATION | First Bank → [BANK] |
Compliance achieved
- Applies a technical measure of the kind UK GDPR Art. 32(1)(a) names, before the file leaves payroll.
- Reduces the breach exposure that UK GDPR Art. 33 puts on a 72-hour clock to the ICO.
- Cuts the case for individual notification under UK GDPR Art. 34, which bites where the risk to workers is high.
- Limits what a stray copy is worth to the unlawful-obtaining offence in DPA 2018 s.170.
- Mask keeps only the last four digits, enough to reconcile a Bacs return without exposing the account.
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Limitations & cautions
A spaced or hyphenated number on a faint scan can defeat OCR, so verify image flags before you share. Masking a copy does not protect the live file: the mandate payroll actually pays from needs access control, not redaction.
Frequently asked questions
How much of an account number may stay visible?
You choose. Mask is normally set to the last four digits, which is enough to match a Bacs return or a query without exposing the full account and sort code together.
Is a leaked payroll bank file a reportable breach?
Usually yes. UK GDPR Art. 33 gives 72 hours to tell the ICO where there is a risk to individuals. Art. 34 adds notification to the workers where that risk is high.
Does masking protect against payroll diversion fraud?
It limits what a leaked copy is worth. Changing an account number is still a process control, so verify the request out of band before you amend a mandate.