Analyses

Breach-notification timelines

How long do organisations take to tell regulators about a data breach, and is it getting faster or slower?

Data as of 2026-09-29 Download the data (CSV)

Median days to report, by year

Washington (from discovery), 2015: 35 daysCalifornia (from end of breach), 2015: 0 days2015Washington (from discovery), 2016: 34 daysCalifornia (from end of breach), 2016: 0 days2016Washington (from discovery), 2017: 37 daysCalifornia (from end of breach), 2017: 0 days2017Washington (from discovery), 2018: 43 daysCalifornia (from end of breach), 2018: 0 days2018Washington (from discovery), 2019: 43 daysCalifornia (from end of breach), 2019: 0 days2019Washington (from discovery), 2020: 36 daysCalifornia (from end of breach), 2020: 0 days2020Washington (from discovery), 2021: 71 daysCalifornia (from end of breach), 2021: 0 days2021Washington (from discovery), 2022: 83 daysCalifornia (from end of breach), 2022: 0 days2022Washington (from discovery), 2023: 67 daysCalifornia (from end of breach), 2023: 0 days2023Washington (from discovery), 2024: 110 daysCalifornia (from end of breach), 2024: 0 days2024Washington (from discovery), 2025: 134 daysCalifornia (from end of breach), 2025: 0 days2025Washington (from discovery), 2026: 99 daysCalifornia (from end of breach), 2026: 0 days2026
Washington (from discovery) California (from end of breach)

Washington: discovery to notice. California: end of breach to notice. The two are different clocks.

Washington: notices after the statutory deadline

YearNoticesMedian days75th pct90th pctPast deadlineMedian residents affected
201514359513645%2,721
201649345412033%1,409
20178337579735%1,236
201863438411644%1,607
201960437014645%1,684
2020204367413658%1,944
20211867114422580%1,643
20221718318329787%1,704
20232536713021485%2,447
202422811021330993%1,940
202520913423237987%2,088
20261549918834390%2,027

Share of notices submitted more than 45 days (before March 2020) or 30 days (since) after the date the organisation reports becoming aware of the breach.

California: days from the end of the breach to the report

YearNoticesWith a breach dateMedian days75th pct90th pctOver 30 days

Method

The two states record different dates, so their numbers are shown side by side and never combined.

  • Washington records the date the organisation says it became aware of the breach and the date it notified the Attorney General. The delay is the days between them, which is the clock the statute uses: notice to the AG is due no more than 45 days after discovery before 1 March 2020 and 30 days after that (RCW 19.255.010). The law allows a delay requested by law enforcement, and “aware” is the organisation's own date, so a notice past the deadline is not by itself a violation. Washington only requires notice to the AG when more than 500 residents are affected.
  • California records only the dates of the breach and the date the notice was posted. The delay is the days from the last listed breach date to the report. It includes the time taken to discover the breach, so it is longer than the legal clock and is not a measure of compliance. Notices that list no breach date are counted but left out of the delay figures.

Years are calendar years of the report date (Washington's own annual report runs from 24 July). Medians and percentiles use linear interpolation. Negative delays, which come from data-entry errors, are left out. The current year is partial.

Sources

Cite this analysis

Keith, M. J. (2026). Breach-notification timelines [Data analysis, data as of 2026-09-29]. mkeith.app. https://mkeith.app/research/analyses/breach-timelines