Notify the PDPC when a Singapore PDPA data breach results in, or is likely to result in, to affected individuals, or is of . Significant scale is 500 or more affected individuals.
The significant-harm route can require notice to both the PDPC and affected individuals, while alone requires PDPC notice. Document the tests and notification decisions separately.
This page is relevant when an incident response team needs to decide whether a Singapore PDPA personal data breach is notifiable to the Personal Data Protection Commission, affected individuals, or both. The key tests are and , supported by documented assessment steps and timing evidence.
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Section 1
What are the Singapore PDPA breach notification thresholds?
The Singapore PDPA breach notification threshold is not a single headcount rule. A breach can be notifiable because it is likely to result in to affected individuals, or because it is of .
is the clearer numeric threshold: the Personal Data Protection (Notification of Data Breaches) Regulations 2021 prescribe 500 affected individuals. PDPC guidance states that an organisation should notify the Commission when it has reason to believe the affected count is at least 500, even if the actual count is still being established.
The 500-individual test does not supersede the test. A smaller breach can still be notifiable if it results in, or is likely to result in, significant harm. Conversely, a breach affecting at least 500 individuals must be notified to the PDPC even when affected-individual notification is not required on the harm facts.
Use to decide whether the Commission and, subject to the statutory exceptions, affected individuals must be notified.
Use to decide whether the Commission must be notified when 500 or more individuals are affected; scale alone does not trigger affected-individual notice.
Do not close a breach as non-notifiable only because the affected count is below 500; check the data classes and harm analysis first.
When the count is uncertain, document the estimate, the source of the estimate, and why it is or is not reasonable to believe the count reaches 500.
PDPC guidance explains that significant-scale breaches require Commission notification even without prescribed significant-harm data.
even if the data breach does not involve any prescribed personal data
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Section 2
How should teams assess significant harm?
Start with the data involved, not the incident label. The Regulations deem where the breach involves an individual's full name, alias, or identification number together with classes in the Schedule, subject to the Schedule's limits. For this rule, identification number includes an identity card number, passport number, another government-issued identity document number used as evidence of nationality or residence, and a foreign identification number.
The Regulations also deem where the breach involves all required account-access elements: an account identifier, such as an account name or number, and a password, security code, access code, response to a security question, biometric data, or other data required to access or use the account.
PDPC guidance describes broadly, including physical, psychological, emotional, economic, financial, reputational, and other harms that a reasonable person would identify as possible outcomes of the breach.
Record each personal data class affected and whether it maps to a prescribed significant-harm category.
Check whether account identifiers were exposed together with credentials, security responses, biometric access data, or equivalent account-access data.
Apply the combinations precisely: a name, alias, or identification number must be paired with a prescribed Schedule data class under regulation 3(1)(a), while the account route requires both an account identifier and the data needed to access or use that account under regulation 3(1)(b).
Assess likely harm in concrete terms: identity misuse, financial loss, account takeover, reputational damage, physical safety risk, or harm to vulnerable individuals.
If the prescribed category analysis is incomplete, keep the breach open for escalation rather than treating it as non-notifiable.
PDPC's self-assessment page states that organisations do not need to report every breach, but should first assess whether the incident is notifiable.
Organisations do not need to report every breach
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Section 3
What assessment record should prove the threshold decision?
PDPC guidance expects organisations with credible grounds to believe a breach occurred to take reasonable and expeditious steps to assess whether it is notifiable, generally within 30 calendar days. The organisation must document all steps taken in the assessment.
The assessment record should be complete enough to support the final notification or non-notification decision. For a notifiable breach, the Regulations require a chronological account of steps taken after awareness of the breach, including the organisation's assessment that the breach is notifiable.
If a data intermediary has credible grounds to believe a breach occurred while processing personal data for another organisation or public agency, it must notify that organisation or public agency without undue delay. The engaging organisation conducts the notifiability assessment and keeps the threshold decision record.
Capture the date and circumstances when the organisation first became aware of the breach.
Record the affected systems, affected individuals or estimate, personal data classes, and whether the breach meets or .
Document containment, remediation, mitigation of harm, and the reasoning for notifying or not notifying affected individuals.
Keep evidence explaining any assessment that takes longer than 30 calendar days and any Commission notification made after the three-calendar-day notification period.
PDPC's self-assessment page supports using a structured assessment before deciding whether to report a breach.
assist with the determination of whether a data breach incident is notifiable
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Section 4
When does the notification clock start?
The Commission notification clock starts after the organisation determines that the breach is notifiable. PDPC guidance states that the Commission must be notified as soon as practicable and no later than three calendar days after that determination.
The first day of the three-day period starts on the day after the organisation makes the notifiable-breach determination. PDPC's example says a breach determined notifiable on 1 January must be notified to the Commission by 4 January.
Affected individuals, where notification is required, must be notified as soon as practicable, at the same time as or after notifying the Commission. PDPC also says that breaches likely to attract widespread public attention or interest should be notified to the Commission before affected individuals or public/media statements.
Record the timestamp for credible grounds to believe a breach occurred, the assessment start, the notifiable-breach determination, and each notification sent.
Notify the Commission within three calendar days after the notifiable-breach determination, not three days after initial discovery.
Sequence affected-individual notices at the same time as or after Commission notification when affected-individual notification is required.
If Commission notification is late, include the reasons for late notification and supporting evidence.
PDPC guidance source for the breach assessment process, 30-calendar-day assessment expectation, notification timing, and practical notification records.
PDPC guidance explains that significant-scale breaches require Commission notification even without prescribed significant-harm data.
PDPC guidance describes the kinds of harm teams should consider when assessing a breach.
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PDPC guidance supports the 30-calendar-day assessment expectation and the need to document assessment steps.
PDPC guidance supports the three-calendar-day Commission notification clock and explains when the first day begins.
"must document all steps taken in assessing the data breach"
More quoted passages
"even if the data breach does not involve any prescribed personal data"
"physical, psychological, emotional, economic and financial harm"
"starts on the day after the organisation makes the determination"
Primary Singapore legislation source for the significant-harm data breach trigger, the 500-individual significant-scale threshold, and required notification contents.
Regulations 3 and 4 define the prescribed significant-harm trigger and set significant scale at 500 affected individuals.
Regulation 3 identifies the prescribed data combinations that are deemed to result in significant harm.
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Regulation 5 lists the information required in a Commission notification, including the assessment and chronology.
"the prescribed number of affected individuals is 500"
More quoted passages
"deemed to result in significant harm to an individual"