Artifact GuideUK72-hour Breach Reporting

UK GDPR 72-Hour Breach Reporting

A controller must notify the ICO without undue delay and, where feasible, within 72 hours after becoming aware of a personal data breach unless it is unlikely to create a risk to people's rights and freedoms.

The controller must separately decide whether a likely high risk means affected people must be told without undue delay. Every personal data breach must be documented, including those not reported.

Author
Sorena AI
Published
May 9, 2026
Updated
Jul 27, 2026
Questions
3

Structured answer sets in this page tree.

Primary sources
5

Cited legal and guidance references.

Publication metadata
Sorena AI
Published May 9, 2026
Updated Jul 27, 2026
Overview

Start the incident record as soon as a possible is escalated. Confirm when the became aware, assess the likely risk to people, notify the ICO if the Article 33 threshold is met, and do not wait for a complete investigation if a phased report is needed. Security incidents that do not affect personal data are outside Articles 33 and 34, but they may trigger other legal, contractual, or sector duties.

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3 of 3 questions
Question 1

When must a controller report a breach to the ICO?

A is a security breach leading to accidental or unlawful destruction, loss, alteration, unauthorised disclosure of, or access to personal data. It covers confidentiality, integrity, and availability failures, not only theft or disclosure.

The must notify the ICO unless the breach is unlikely to result in a risk to people's rights and freedoms. If notification is required, it must be made without undue delay and, where feasible, within 72 hours after the controller becomes aware. A must notify its controller without undue delay after becoming aware; Article 33 does not give processors their own 72-hour ICO deadline, although the contract may set a shorter escalation period.

  • Record the 's time and the facts that made the breach reasonably certain.
  • Assess the type of harm, affected people, sensitivity and volume of data, ease of identification, likely consequences, and measures already protecting the data.
  • Notify the ICO when risk is possible; record a reasoned decision when the breach is unlikely to result in risk.
  • Do not confuse the lower ICO-notification risk threshold with the high-risk threshold for telling affected people.
Citations
Question 2

What must the ICO report and incident record contain?

The Article 33 report must, where possible, describe the nature of the breach, including the categories and approximate numbers of affected people and personal-data records; give the data protection officer's or other contact's details; describe likely consequences; and describe measures taken or proposed to address the breach and mitigate harm.

If all information is not available at once, provide it in phases without undue further delay. A report made after 72 hours must include reasons for the delay. Keep the submission, receipt, later updates, and decision trail with the incident record.

  • Timeline: discovery, escalation, , containment, risk decisions, ICO report, updates, and individual communications.
  • Scope: systems, data categories, affected people and records, jurisdictions, processors, and recipients.
  • Assessment: likely consequences, likelihood and severity of harm, protective measures, residual risk, and decision-maker.
  • Response: containment, recovery, credential resets, communications, further investigation, lessons learned, and control changes.
Citations
Question 3

When must affected people be told?

Article 34 requires the to communicate the breach to affected people without undue delay when it is likely to result in a high risk to their rights and freedoms. The communication must use clear, plain language and include the contact point, likely consequences, and measures taken or proposed, including mitigation.

Direct communication is not required if appropriate measures made the data unintelligible to unauthorised people, later measures ensure the high risk is no longer likely to materialise, or direct contact would involve disproportionate effort. In the last case, the must use a public communication or similarly effective measure. These exceptions must be assessed against the actual breach; encryption helps only if the keys and implementation remained secure.

  • Tell people what happened and what information was affected.
  • Explain the likely effects without speculation or minimising the risk.
  • State what the organisation has done and what the person can do to protect themselves.
  • Keep the high-risk assessment and any Article 34 exception rationale with the breach record.
Citations
Primary sources

References and citations

ico.org.uk
Referenced sections
  • Provides the current ICO reporting route and operational information organisations need before submitting a report.
legislation.gov.uk
Referenced sections
  • Binding UK GDPR text for supervisory-authority notification, processor escalation, records, and communication to affected people.
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