F10 notification
An F10 is the online form used to notify the Health and Safety Executive about a construction project. Under CDM 2015 (regulation 6) a project is notifiable if the construction work will last more than 30 working days and have more than 20 workers working at the same time at any point, or exceed 500 person days.
The two tests
| Test | Example | Notifiable? |
|---|---|---|
| More than 30 working days and more than 20 workers at once | 8-week extension with 22 people on site in week 5 | Yes |
| More than 30 working days, never more than 20 at once | 12-week refurbishment, peak of 12 workers, 400 person days | No |
| More than 500 person days | 6 workers for 90 working days = 540 person days | Yes |
A person day is one person working one shift, including supervisors and specialists.
Who submits it and when?
- The client is responsible, but can ask someone else (often the principal designer or principal contractor) to submit it.
- For domestic clients, the duty passes to the contractor or principal contractor.
- Submit it as soon as practicable before the construction phase begins, through the F10 form on the HSE website.
After submitting
- Display a copy of the notification on site where workers can see it, for example in the welfare cabin.
- Update it if the details change, for example a new principal contractor.
- Notification does not change your other CDM duties: every project, notifiable or not, needs a construction phase plan and properly planned work.
Notifiable or not, you need the plan. Make a construction phase plan and RAMS for each trade in minutes, free, as PDFs ready to hand to the client.
Construction phase plan Make RAMSQuestions
Is there a fee for an F10?
No. The online notification to HSE is free.
Does a domestic extension need an F10?
Only if it meets one of the two tests. Most single-storey extensions do not, but larger projects with many trades can exceed 500 person days.
Does notification make HSE visit the site?
Not automatically, but HSE uses notifications to plan inspections.
Checked against CDM 2015 regulation 6 and HSE's F10 guidance, October 2026. Related: CDM regulations explained.