Unknown data breaches reported to the ICO
The unknown sector reported 82 personal-data breaches to the UK Information Commissioner's Office in Q4 2025 — 2.2% of all reported incidents, ranking it #13 of 22 sectors by volume.
Quick answer
In Q4 2025, the unknown sector reported 82 personal-data breaches to the UK ICO, which is 2.2% of the 3,677 breaches reported across all sectors and makes it the #13 highest-volume sector of 22.
Source: ICO (Information Commissioner's Office) — Data security incident trends (data-security-incidents-trends-q1-2019-to-q4-2025.xlsx). Contains public sector information licensed under the Open Government Licence v3.0. Figures are distinct-incident counts for Q4 2025, retrieved 2026-06-25. Presented neutrally; this is statistics, not legal advice.
Other sectors
Compare with every other sector's reported breach volume in Q4 2025.
FAQ
- How many data breaches did the unknown sector report to the ICO in Q4 2025?
- The unknown sector reported 82 distinct personal-data breaches to the UK ICO in Q4 2025. That is 2.2% of the 3,677 breaches reported across all sectors, ranking it #13 of 22 sectors by volume. Figures are taken directly from the ICO's published 'Data security incident trends' statistics.
- Is the unknown sector a high-breach sector?
- In Q4 2025 the unknown sector ranked #13 of 22 sectors by reported breach volume, accounting for 2.2% of all reported personal-data breaches. Volume reflects both the number of organisations in a sector and how diligently they report — a higher count is not on its own evidence of weaker controls.
- What should unknown organisations do to reduce breach risk?
- Because the highest-volume incident types across all sectors are misdirected email, phishing and unauthorised access, the most effective controls are practical: delayed-send and recipient confirmation on email, mandatory bcc for bulk mail, multi-factor authentication and least-privilege access, redaction checks before disclosure, and a tested 72-hour breach-response process. A structured GDPR audit maps your data flows against these obligations.
Data retrieved 2026-06-25 · reporting period Q4 2025.
Cut your breach risk before it becomes a report to the ICO
Most breaches in this data are preventable — misdirected email, weak access controls, phishing. GeraCompliance's fixed-scope GDPR sprint maps your data flows, hardens the controls behind these incident types, and gives you a tested breach-response plan — in days, not months.