A controller reports a to the ICO unless it is unlikely to risk people's rights and freedoms. The deadline is without undue delay and, where feasible, within 72 hours of awareness.
Use this guide for implementation planning, not as a substitute for checking the consolidated UK GDPR, applicable Data Protection Act 2018 provisions, current ICO guidance, contracts, and the facts of the processing.
The 72-hour rule is not a requirement to report every cyber event. It applies when a controller becomes aware of a unless that breach is unlikely to result in a risk to people's rights and freedoms. The controller must notify the ICO without undue delay and, where feasible, within 72 hours; processors notify their controller without undue delay, not on a separate 72-hour ICO clock.
First decide whether the event is a : a security breach that causes accidental or unlawful destruction, loss, alteration, unauthorised disclosure of, or access to personal data. Confidentiality, integrity, and availability incidents can qualify; an unsuccessful attack that does not compromise personal data does not.
Record when the controller had a reasonable degree of certainty that personal data had been compromised. That awareness starts the 72-hour period. An internal escalation delay does not reset the clock, so processors and frontline teams need immediate reporting routes.
Assess likely harm to people, not only damage to the organisation. Consider the data, identifiability, number and characteristics of people affected, exposure, possible misuse, duration, and whether measures such as effective encryption make harmful consequences unlikely.
Sources (3)
Explains notifiable breach timing, phased updates, and the information controllers must provide to the ICO.
Confirms the ICO reporting route and the practical report early, update later approach for complex breaches.
Primary legal text for controller notification duties, processor escalation, records, and required notification content.
The controller owns the ICO decision. Security, legal, privacy, operations, communications, and the relevant processor may supply facts, but the record must identify one decision owner and an alternate. Preserve the first alert, awareness rationale, risk assessment, containment evidence, submission receipt, phased updates, and individual-notice decision.
Sources (3)
Explains notifiable breach timing, phased updates, and the information controllers must provide to the ICO.
Confirms the ICO reporting route and the practical report early, update later approach for complex breaches.
Primary legal text for controller notification duties, processor escalation, records, and required notification content.
A processor tells its controller without undue delay; the controller applies the Article 33 threshold and ICO deadline. If the same event affects processing subject to another regime or another jurisdiction, assess those notification duties separately.
Article 34 uses a higher threshold than ICO reporting. Direct notice is not required where appropriate protection made the data unintelligible, later measures removed the likely high risk, or direct notice would require disproportionate effort and an equally effective public communication is used.
The ICO's examples show why the facts control: disclosure of patient records is likely to create high risk because of the sensitivity and confidentiality of the information; deletion of alumni contact details later restored from backup is unlikely to create high risk; and medical records sent to another professional who immediately alerts the sender and securely deletes them may be unlikely to create a risk. These are examples, not automatic classifications.
Sources (3)
Explains notifiable breach timing, phased updates, and the information controllers must provide to the ICO.
Confirms the ICO reporting route and the practical report early, update later approach for complex breaches.
Primary legal text for controller notification duties, processor escalation, records, and required notification content.
The initial report may be incomplete, but it should state what is known, what remains under investigation, and when updates are expected. Keep the filed version and submission confirmation with the underlying breach record.
Article 33 requires the controller to document the facts, effects, and remedial action for every . Add the awareness analysis, notification threshold, reasons for delay, and Article 34 decision so the ICO can verify the process.
Sources (3)
Explains notifiable breach timing, phased updates, and the information controllers must provide to the ICO.
Confirms the ICO reporting route and the practical report early, update later approach for complex breaches.
Primary legal text for controller notification duties, processor escalation, records, and required notification content.
Assign awareness timing, risk assessment, ICO reporting, phased updates, individual notice, and the breach record.
Create scoped reporting questions, evidence fields, and review tasks.
Use Research Copilot to answer follow-up questions with cited source material.
Review scope, evidence, owners, and the next compliance actions with Sorena.
Use UK transfer approval regulations by checking the destination, recipient, data, sector, effective status, scope limits, and review evidence.
Current UK GDPR rules for significant solely automated decisions, meaningful human involvement, Article 22B restrictions, and Article 22C safeguards.
Apply the UK GDPR material and territorial scope tests to one processing activity, including exclusions, non-UK organisations, roles, and evidence.
Build UK GDPR Article 30 records for controller and processor activities, apply the narrow under-250 exception, and keep the records current and available to the ICO.
Decide whether a personal data breach must be reported to the ICO or communicated to individuals, with deadlines, exceptions, content, and evidence.
Run a UK GDPR personal data breach workflow from containment and awareness through risk assessment, ICO reporting, individual notice, and the breach record.
Apply UK GDPR children's protections and the Age Appropriate Design Code to online services likely to be accessed by children.
A practical guide to Children's Code scope, its 15 standards, age 13 consent, evidence, exceptions, and product implementation.
A verifiable UK GDPR checklist for scope, lawful processing, transparency, rights, governance, security, breaches, DPIAs, children, and transfers.
Answer common UK GDPR questions on scope, lawful basis, records, DPIAs, DPOs, rights, breaches, children, automated decisions, and international transfers.
Build a UK GDPR compliance programme around processing records, lawful decisions, rights operations, security, incidents, DPIAs, suppliers, and transfers.
Decide whether each party is a controller, joint controller, or processor under the UK GDPR, then record the role-specific duties, contract terms, and evidence.
Operate UK GDPR access, rectification, erasure, restriction, portability, objection, and automated-decision rights under the amended Article 12 timing rules.
Track UK GDPR deadlines for rights requests, privacy information, breach notification, DPIAs, and ICO prior consultation, with triggers and exceptions.
Screen UK GDPR processing for likely high risk, complete the required DPIA analysis before processing, reduce risk, and consult the ICO when high residual risk remains.
Decide when the UK GDPR requires a DPIA or DPO, what each must cover, when to consult the ICO, and what evidence to retain.
Run a UK subject-access workflow using the current Article 12A clock, reasonable identity and clarification steps, proportionate searches, exemptions, redactions, and response evidence.
Choose the UK IDTA or Addendum, complete the current Article 46 data protection test, add needed measures, and maintain evidence for restricted transfers.
Choose among the six familiar Article 6 bases and the UK's recognised legitimate interests basis, then document any Article 9 or 10 condition.
UK GDPR and PECR cookie guidance with practical consent, exemption, evidence, and cited implementation decisions.
Understand the UK GDPR £8.7 million or 2% and £17.5 million or 4% fine ceilings, which infringements fall into each band, and how the ICO sets a fine.
Map UK GDPR requirements by processing activity, role, lawful basis, data type, risk, rights, suppliers, automated decisions, and transfers.
Apply the UK GDPR restricted-transfer sequence: map the transfer, check Article 45A approval, choose an Article 46 safeguard and assessment, or justify a specific Article 49 derogation.
Decide whether a UK restricted transfer exists, whether adequacy applies, how to use the IDTA or UK Addendum, and how to document the data protection test.
See when to use the UK GDPR, when the Data Protection Act 2018 adds a condition or exemption, and which regime covers law enforcement or intelligence processing.
Determine whether UK GDPR, EU GDPR, or both apply, then separate representatives, regulators, transfer routes, national law, and post-Brexit UK amendments.
Choose between the UK IDTA and EU SCCs with the UK Addendum, complete the right documents, and record the separate UK and EU transfer assessments.
Compare current UK and EU rules for recognised legitimate interests, rights requests, access searches, automated decisions, and international transfers.
Configure separate UK and EU privacy operations for representatives, regulator contacts, rights requests, breach reporting, transfer tools, and evidence.
Choose and document the UK GDPR lawful basis that fits each processing purpose, including recognised legitimate interest, in force since 5 February 2026.
Decide whether an online service is likely to be accessed by UK children and apply the ICO Children's Code standards to product design and personal-data use.
Decide whether a personal data breach must be reported to the ICO, when the 72-hour clock starts, what the report needs, and when affected people must be told.
Check whether current UK adequacy regulations cover a restricted transfer, including partial coverage for Canada, Japan, and the US UK Extension.
Apply the current UK rules for significant solely automated decisions, special-category restrictions, meaningful human involvement, and Article 22C safeguards.
See which controllers and processors need records of processing activities, what each record must contain, and how the under-250-employee exemption works.
Decide whether each party is a controller, joint controller, processor, or sub-processor, then record the contracts, responsibilities, and evidence the role requires.
Screen for likely high-risk processing, complete the Article 35 assessment before processing, and consult the ICO if high residual risk remains.
Apply the three UK GDPR DPO triggers and document expertise, independence, reporting line, resources, tasks, contacts, and conflict controls.
Decide when to use the UK IDTA or Addendum, complete the Article 46 data protection test, add supplementary measures, and keep the transfer under review.
Apply the current UK PECR rules to cookies and similar technologies, including consent, five exceptions, UK GDPR overlap, and evidence.