Census de-identification is the removal of staff PII from a workforce data set. Health, union, and other special-category fields fall under GDPR Art. 9. Once the output is truly anonymous (Recital 26), it leaves scope. anonym.plus runs locally.
When this applies
A workforce census lists each employee with pay, role, and sometimes health or union data. A buyer needs the headcount math, not the people.
How anonym.plus handles it
- Point anonym.plus at the census file on your device.
- It scans ID columns and any free-text note fields.
- Special-category fields under Art. 9 get extra care.
- Swap staff for steady labels to keep joined rows.
- Save the clean data set on your device.
What you need to provide
- The census (XLSX, CSV, or export).
- A column map for known ID and sensitive fields.
- Replace with the map off for true anonymity.
PII entity types detected
| Category | anonym.plus entity type | Example |
|---|---|---|
| Names | PERSON | employee_name → [STAFF_n] |
| Identifiers | NATIONAL_ID | social no. → [ID] |
| Health | MEDICAL_LICENSE | leave reason → [SENSITIVE] |
| Contact | EMAIL_ADDRESS | work email → [EMAIL] |
| Dates | DATE_TIME | hire date → [DATE] |
| Location | LOCATION | home address → [ADDRESS] |
Compliance achieved
- Strips GDPR Art. 9 special-category staff data.
- True anonymity puts the data set beyond GDPR by Recital 26.
- Local-only work supports EU data residency.
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Limitations & cautions
Art. 9 fields like health or union status carry the highest risk. A rare role plus a small team can re-identify even after IDs go. Weigh the residual risk and keep no re-link key for true anonymity.
Frequently asked questions
Why is census data special under GDPR?
It can hold health, union, or other Art. 9 data, which needs strong safeguards. Making it anonymous drops that burden for headcount and cost work.
Can rows stay linkable after the swap?
Yes. A steady label map keeps each employee's rows joined while no real identity is left.
Does it handle both columns and free text?
Yes. Tidy ID columns and inline note fields are both checked on your device.