# Standards and Regulatory References

## Primary Legislation

### GDPR Article 33 — Notification of a Personal Data Breach to the Supervisory Authority
- **Art. 33(1)**: In the case of a personal data breach, the controller shall without undue delay and, where feasible, not later than 72 hours after having become aware of it, notify the personal data breach to the supervisory authority competent in accordance with Art. 55, unless the personal data breach is unlikely to result in a risk to the rights and freedoms of natural persons. Where the notification to the supervisory authority is not made within 72 hours, it shall be accompanied by reasons for the delay.
- **Art. 33(2)**: The processor shall notify the controller without undue delay after becoming aware of a personal data breach.
- **Art. 33(3)**: The notification referred to in paragraph 1 shall at least: (a) describe the nature of the personal data breach including where possible, the categories and approximate number of data subjects concerned and the categories and approximate number of personal data records concerned; (b) communicate the name and contact details of the data protection officer or other contact point; (c) describe the likely consequences of the personal data breach; (d) describe the measures taken or proposed to be taken by the controller to address the personal data breach, including, where appropriate, measures to mitigate its possible adverse effects.
- **Art. 33(4)**: Where, and in so far as, it is not possible to provide the information at the same time, the information may be provided in phases without undue further delay.
- **Art. 33(5)**: The controller shall document any personal data breaches, comprising the facts relating to the personal data breach, its effects and the remedial action taken. That documentation shall enable the supervisory authority to verify compliance with this Article.

### GDPR Article 34 — Communication of a Personal Data Breach to the Data Subject
- **Art. 34(1)**: When the personal data breach is likely to result in a high risk to the rights and freedoms of natural persons, the controller shall communicate the personal data breach to the data subject without undue delay.
- **Art. 34(2)**: The communication shall describe in clear and plain language the nature of the personal data breach and contain at least the information and measures referred to in points (b), (c) and (d) of Art. 33(3).
- **Art. 34(3)**: Exemptions from individual notification where: (a) appropriate technical and organisational protection measures were applied (e.g., encryption); (b) subsequent measures ensure the high risk is no longer likely to materialise; (c) it would involve disproportionate effort, in which case a public communication shall be made.

### GDPR Article 4(12) — Definition of Personal Data Breach
- "A breach of security leading to the accidental or unlawful destruction, loss, alteration, unauthorised disclosure of, or access to, personal data transmitted, stored or otherwise processed."

## Regulatory Guidance

### EDPB Guidelines 9/2022 on Personal Data Breach Notification under GDPR
- Adopted 28 March 2023 (Version 2.0), replacing WP250rev.01.
- Section 2.1: Definition of breach — clarifies that a breach is a type of security incident, but not every security incident is a personal data breach.
- Section 2.3: "Becoming aware" — the controller is aware when it has a reasonable degree of certainty that a security incident has occurred leading to personal data compromise.
- Section 3.1: Risk assessment methodology — provides a structured approach to evaluating whether a breach is "likely to result in a risk."
- Section 4: Notification content — detailed guidance on each element of Art. 33(3).
- Section 5: Phased notification — practical guidance on providing information in phases under Art. 33(4).
- Annex: 18 breach scenarios with recommended notification actions.

### EDPB Guidelines 01/2021 on Examples Regarding Data Breach Notification
- Provides 18 practical breach scenarios including ransomware attacks, data exfiltration, human error incidents, lost devices, and social engineering attacks.
- For each scenario, specifies whether supervisory authority notification and data subject notification are required, with reasoning.

### National Supervisory Authority Guidance
- **ICO (UK)**: "Personal data breaches: a guide" — clarifies that the 72-hour window applies from the moment the controller becomes aware, not when the breach occurred. Provides practical examples of awareness triggers.
- **CNIL (France)**: "Les violations de données personnelles" — details the CNIL's online notification process and required fields in the French notification form.
- **BfDI (Germany)**: "Meldung von Datenschutzverletzungen" — specifies that notification to the competent state DPA (Landesdatenschutzbehörde) is required unless the breach relates to telecommunications or postal services (which fall under BfDI jurisdiction).

## Enforcement Precedents

- **Dutch DPA (AP) — Booking.com Fine of EUR 475,000 (March 2021)**: Late notification of a breach affecting 4,109 customers. The breach was reported 22 days late. The AP emphasized that the 72-hour obligation is strict and that internal processes do not justify delay.
- **German DPA (Hamburg) — Twitter/X Fine of EUR 450,000 (December 2020)**: Failure to notify a data breach within 72 hours and to adequately document the breach. Notification was made only after media reporting.
- **Spanish AEPD — CaixaBank Fine of EUR 6,000,000 (January 2021)**: Multiple GDPR violations including inadequate breach notification procedures (Art. 33) combined with insufficient security measures (Art. 32).
- **Belgian DPA — Decision 80/2021**: Controller failed to notify a breach where employee data was sent to the wrong recipient. The DPA held that even "minor" breaches involving identifiable personal data must be assessed against the Art. 33 threshold.

## ISO/IEC Standards

- **ISO/IEC 27701:2019** — Section 6.13.1.1: Requires documented procedures for identifying and reporting privacy breaches, aligned with GDPR Art. 33/34.
- **ISO/IEC 27035-1:2023** — Information Security Incident Management Part 1: Principles and Process. Provides the underlying incident management framework upon which breach notification procedures should be built.
- **ISO/IEC 27035-2:2023** — Part 2: Guidelines to plan and prepare for incident response. Covers preparation of notification templates and escalation procedures.