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HSE F10 Notification: When You Must Notify and How to Submit

By Brian Crocker

Quick answer: The F10 is the online notification form submitted to the Health and Safety Executive when a construction project crosses the CDM 2015 notification thresholds — more than 30 working days with more than 20 simultaneous workers at any point, or more than 500 person-days total. The client bears the legal duty to notify, though in practice the principal contractor or principal designer often submits on the client's behalf. Notification must happen before the construction phase begins.

If you are a principal contractor or principal designer taking on a notifiable project, this is one of the first administrative steps — and one of the most commonly rushed or forgotten ones. Assessors checking your CDM compliance will ask whether notification was made, when, and whether the displayed notice was kept current.

This guide explains exactly when notification is required, what the F10 asks for, who submits it, and what assessors look for.

Disclaimer: This guidance is based on the Construction (Design and Management) Regulations 2015 and current HSE published guidance. TenderReady is not affiliated with the HSE or any accreditation scheme. Always verify requirements directly with the HSE before relying on this information.

When Is F10 Notification Required?

CDM 2015 Regulation 6 sets out the notification thresholds. A construction project is notifiable if the construction work is scheduled to:

(a) last longer than 30 working days and have more than 20 workers working simultaneously at any point, or

(b) exceed 500 person-days in total.

These are cumulative calculations, not estimates of typical activity. A project could have 30 workers on site for a single high-activity week and clear the simultaneous-worker threshold even if total duration is modest. Both conditions in (a) must be met at the same time — a 40-day project where no more than 5 workers are ever on site simultaneously does not meet threshold (a), though it may still clear threshold (b) depending on total person-days.

Person-days calculation: Multiply the number of workers by the number of days they work on site. Ten workers for 50 days = 500 person-days — not notifiable, because regulation 6(1)(b) is worded as "exceed 500 person days" and 500 does not exceed 500. Eleven workers for 50 days = 550 person-days — notifiable.

When the project is on a railway, notification goes to the Office of Rail and Road rather than the HSE. For work on nuclear sites, notification goes to the Office for Nuclear Regulation.

Who Is Responsible for Submitting?

The client carries the legal duty to notify the HSE. Regulation 6 places the obligation on the client — not the principal contractor, not the principal designer.

In practice, however, clients frequently delegate the task. The HSE's F10 guidance is explicit about when delegation works:

  • Commercial clients must notify directly, or formally authorise the principal designer or principal contractor to do so on their behalf.
  • Domestic clients may have the notification duty fall to the contractor or principal contractor by default under CDM 2015, or it can be transferred to the principal designer by written agreement.

If you are the principal contractor and you submit the F10 on the client's behalf, make sure you have clear, documented authorisation to do so. Submitting without authorisation does not transfer the client's legal liability — and if the notification is challenged, the client will still be the party held responsible.

What the F10 Requires

The F10 notification must include the particulars listed in Schedule 1 of CDM 2015. These are:

  1. The date the notice is forwarded to the HSE
  2. The address or a precise location description of the construction site
  3. The name of the local authority in whose district the site is located
  4. A brief description of the project and the construction work involved
  5. The client's name, address, telephone number, and email (if available)
  6. The principal designer's name, address, telephone number, and email (if available)
  7. The principal contractor's name, address, telephone number, and email (if available)
  8. The planned start date for the construction phase
  9. The time allocated by the client for the construction work
  10. The planned duration of the construction phase
  11. The estimated maximum number of workers on site at any one time
  12. The planned number of contractors on site
  13. The name and address of any contractor already appointed
  14. The name and address of any designer already appointed
  15. A declaration signed by or on behalf of the client that the client is aware of their duties under these Regulations

The online form — submitted at form.hse.gov.uk/f10 — walks through these particulars in sequence. Once submitted, the HSE issues a unique serial number that can be used to access or update the notification.

HSE no longer accepts paper forms, email, or postal notifications. Online submission is the only route.

When to Submit

Regulation 6 requires notification "as soon as is practicable before the construction phase begins." There is no fixed number of days, but in practice the expectation is clear: notification should happen during the pre-construction phase, before site set-up starts. Waiting until workers are already on site is too late.

For projects where a principal designer has been appointed, a sensible workflow is:

  1. Client confirms the project is notifiable (checks the thresholds).
  2. Principal designer or principal contractor prepares the notification with the available particulars — some (like the estimated maximum workforce) may be estimates at this stage.
  3. Notification is submitted before construction phase mobilisation.
  4. The unique serial number is retained and the notification is displayed on site.

The notification can and should be updated if key particulars change — a significant increase in peak workforce, a different principal contractor, or an extended duration all warrant an update via the same serial number.

The On-Site Display Requirement

CDM 2015 requires the F10 notification to be "clearly displayed in the construction site office in a comprehensible form where it can be read by any worker." This is not optional, and it is one of the first things a visiting HSE inspector looks for on a notifiable project.

In practice, print the confirmation page or save the notification confirmation as a PDF and post it in the site office. Keep it current — if you updated the notification online, the displayed copy must reflect the updated version.

If you are submitting through an accreditation application and your portfolio includes notifiable projects, assessors may ask for evidence of notification. The serial number confirmation from the online submission is sufficient documentation.

Special Circumstance: Single-Contractor Projects

If only one contractor is involved in a project that still clears the notification thresholds — which is uncommon, but not impossible for specialist single-trade projects of long duration — the HSE guidance is to enter the sole contractor's name as both the principal designer and the principal contractor on the form, and to use the text box to clarify that the project involves only one contractor.

What Assessors Look For

If your accreditation application includes evidence of managing notifiable projects — or if you are applying for a tier that requires demonstrating CDM competence as a principal contractor — assessors will look for:

  • Evidence that you identified the project as notifiable (showed you understood the thresholds)
  • Proof that notification was made before the construction phase started (not retrospectively)
  • That the displayed notice was kept current as the project evolved
  • That the F10 was made by or with proper authority from the client

The most common compliance gap is not failing to notify at all — it is notifying late (after site activities had already begun) or not updating the notification when key details changed. Both suggest a reactive rather than a managed approach to CDM obligations.

How This Connects to Your Accreditation Application

SSIP assessors — whether reviewing your application for CHAS, SafeContractor, SMAS or another SSIP Registered Member, or the Once For All Health & Safety assessment that sits inside a Constructionline Gold membership — assess your CDM knowledge and documentation practices as part of the health and safety management system questions. For principal contractors, the F10 requirement sits within the broader CDM framework covered in your CDM 2015 duties guide and the specific principal contractor role covered in our

CDM principal contractor and principal designer guide.

For notifiable projects, the F10 is a prerequisite — you cannot correctly run the construction phase without having notified. Assessors know this. If you have managed notifiable projects and cannot produce an F10 confirmation or describe your notification process, it creates a gap in your evidence.

The Construction Accreditation Readiness Scorer will flag CDM documentation gaps if you have not yet documented your notification processes.

Summary

The F10 notification is the mechanism by which the HSE is informed of construction projects that cross the CDM 2015 thresholds — more than 30 working days with more than 20 simultaneous workers, or more than 500 person-days. The client is legally responsible for submitting it, though the duty can be delegated to the principal contractor or principal designer with proper authorisation. Notification must happen before the construction phase begins, the confirmation must be displayed on site throughout, and the notification must be updated if material details change. For accreditation purposes, being able to demonstrate a managed, timely F10 process is part of showing CDM competence as a principal contractor.

Sources and References

  • CDM 2015 Regulation 6 — notification requirements (legislation.gov.uk)
  • CDM 2015 Schedule 1 — particulars required in notification (legislation.gov.uk)
  • HSE F10 notification guidance (hse.gov.uk)
  • F10 online submission form (form.hse.gov.uk)
  • SSIP Forum Members register — Registered Member vs Supporter Member categories ("Registered Members: SSIP Assessments" / "Supporter Members: Recognise SSIP in their Supply Chain"; Constructionline is listed as a Supporter Member) (ssip.org.uk)

Last reviewed: June 2026. Guidance based on the Construction (Design and Management) Regulations 2015 (SI 2015/51). TenderReady is not affiliated with the Health and Safety Executive or any accreditation scheme. This guide summarises publicly available regulatory requirements — always verify with the HSE and your accreditation scheme directly.