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FeaturesCalmony Sanctions MonitorUpdated March 12, 2026

GDPR Article 33 Compliance: Data Breach Notification Procedure

GDPR Article 33 Compliance: Data Breach Notification Procedure

Release: v0.1.144 Control: GDPR-10 Framework: GDPR


Overview

GDPR Article 33 requires that any organisation acting as a data controller notify the relevant supervisory authority — in the UK, the Information Commissioner's Office (ICO) — within 72 hours of becoming aware of a personal data breach. Failure to have a documented procedure in place is itself a compliance risk, independent of whether a breach has occurred.

Version 0.1.144 closes this gap by introducing a formal incident response runbook (INCIDENT_RESPONSE.md) in the repository root.


What the Procedure Covers

The INCIDENT_RESPONSE.md runbook documents five mandatory areas:

1. Breach Detection Triggers

Indicators that should prompt an immediate internal investigation, such as:

  • Unauthorised access to personal data stores
  • Accidental disclosure of sensitive records
  • Loss or theft of devices containing personal data
  • Anomalous data export activity surfaced by monitoring alerts

2. Internal Escalation Process

A defined chain of ownership from first responder through to Data Protection Officer (DPO) or nominated compliance lead, with clear timelines to ensure the 72-hour window is not missed.

3. ICO Notification Procedure

Step-by-step guidance for reporting a breach to the ICO:

  • Deadline: Within 72 hours of discovery
  • Reporting portal: ico.org.uk/report-a-breach
  • Required information: nature of the breach, categories and approximate number of data subjects affected, likely consequences, measures taken or proposed

Note: If notification cannot be made within 72 hours, the reasons for the delay must be provided alongside the notification.

4. Affected Data Subject Notification Template

A pre-drafted communication template for notifying individuals whose personal data has been compromised (required under GDPR Art. 34 where the breach is likely to result in a high risk to those individuals).

5. Post-Incident Review Process

A structured retrospective framework to identify root cause, assess control failures, and document remediation actions to prevent recurrence.


Repository Artefact

FileLocationPurpose
INCIDENT_RESPONSE.mdRepository rootFull breach notification runbook

The privacy policy has been updated to link directly to this document.


Regulatory Reference

ItemDetail
RegulationUK GDPR / EU GDPR
ArticleArt. 33 — Notification to supervisory authority
Art. 34Notification to data subjects (high-risk breaches)
Supervisory authorityInformation Commissioner's Office (ICO)
ICO reporting portalico.org.uk/report-a-breach
Notification deadline72 hours from discovery

Related Controls

  • GDPR-10 — Breach notification to supervisory authority (Art. 33) ✅ Addressed in this release
  • GDPR Art. 34 — Notification to affected data subjects (referenced in runbook)
  • GDPR Art. 30 — Records of processing activities

No Application Changes

This release is documentation-only. No API endpoints, data models, or application behaviour were altered.