What mandatory occurrence reporting is
Mandatory occurrence reporting (MOR) is the statutory duty to report certain building safety occurrences to the Building Safety Regulator. For occupied higher-risk buildings in England, the duty sits in BSA s.87 and the operational rules in SI 2023/907 regulation 6. Treat the Act and the regulation as one reporting regime — not two disconnected checklists.
MOR exists so significant fire-spread and structural-failure risks are visible to the regulator promptly — with an auditable trail of what the duty-holder knew, when it came to their attention, and what was reported.
Key legal facts
What must be reported
Notifiable safety occurrences that meet the statutory tests — typically events that cause, or if not remedied are likely to cause, a significant risk of death or serious injury from fire spread or structural failure in an HRB context.
Notice ASAP, report in 10 calendar days
Under BSA s.87 and SI 2023/907 reg.6, notice must be given as soon as reasonably practicable. Where a full report is required, it must reach the Building Safety Regulator within 10 calendar days of the day the occurrence came to the Accountable Person’s attention — unless an extension is granted.
Who is responsible
Occupied-phase duties sit with Accountable Persons / the Principal Accountable Person. Design and construction phases have related occurrence duties for duty-holders under the gateway regime — keep phase roles clear.
Evidence the regulator expects
A defensible MOR system is not an inbox. It needs intake, triage, attention-based deadline tracking, investigation notes, evidence links in the golden thread, and proof of what was reported to the BSR and when.
Link to the BAC pack
GOV.UK BAC guidance expects evidence of the mandatory occurrence reporting system as part of the application pack. Incomplete MOR arrangements undermine BAC readiness.
Notice ASAP and the 10-day full-report window
SI 2023/907 reg.6 requires notice as soon as reasonably practicable. Where a full report is required, the report must reach the BSR within 10 calendar days of the day the occurrence came to the Accountable Person’s attention — unless an extension is granted. Duty-holders need deadline visibility from that attention date, not a calendar reminder after the window has closed.
- Log when the occurrence came to the AP’s attention and the reportability decision
- Surface days remaining / overdue status to APs and BSMs
- Capture investigation notes and golden-thread evidence
- Record what was filed to the BSR and when (manual portal reference)
A system, not an inbox
Spreadsheets and shared inboxes fail MOR because they cannot prove triage, attention-based deadlines, evidence links, or submission history under scrutiny. A defensible system connects intake → assessment → deadline → evidence → BSR report reference — and feeds lessons learned back into the safety case.
BAC pack and safety case links
GOV.UK Building Assessment Certificate guidance expects evidence of the mandatory occurrence reporting system as part of the application pack. Incomplete MOR arrangements undermine BAC readiness even when the safety case narrative looks polished.
How Threadsovereign covers MOR
Every paid plan includes mandatory occurrence reporting workflows with attention-based deadline status in the occupied portal and an audit trail for duty-holder evidence. Official filing remains on the BSR / GOV.UK portal — Threadsovereign prepares, tracks, and evidences; it does not auto-file to HSE.
Product walkthrough: Accountable Person software.
Primary sources
- BSA 2022 s.87 — Mandatory occurrence reporting duty (opens in a new tab)
- SI 2023/907 reg.6 — Mandatory occurrence reporting (occupied) (opens in a new tab)
- GOV.UK — Submitting mandatory occurrence notices and reports (opens in a new tab)
- GOV.UK — Accountable persons for higher-risk buildings (opens in a new tab)
- GOV.UK — Preparing a building assessment certificate application (updated 1 Apr 2026) (opens in a new tab)
FAQ
Cochise Derrick
Founder & Director
Cochise Derrick is the founder and director of Threadsovereign Ltd and the sole architect and developer of the Threadsovereign platform. With a background as a lead developer on central government digital services and current SC clearance, he brings the technical depth and regulatory understanding required to build compliance infrastructure that duty-holders can genuinely rely on. Threadsovereign is the result of over a year of focused development against the Building Safety Act 2022 and its statutory instruments.
Areas of focus
Implement this in Threadsovereign
Statutory workflows sit on every paid plan. Prepare and evidence in-platform; file on the official BSR portal.