F10: when and how to notify the HSE of a construction project

An F10 is the notification of a notifiable construction project to the Health and Safety Executive in Great Britain. It is part of the Construction (Design and Management) Regulations 2015, not a substitute for a construction phase plan, risk assessment, or appointing the right duty holders. Northern Ireland uses a separate framework. The project's client has the notification duty. The official route is the HSE F10 online service, which links to the current form.

The two notification tests

Under CDM 2015 regulation 6, a project is notifiable if the construction work is scheduled to:

1. Last longer than 30 working days and have more than 20 persons on site at any point during construction; or
2. Exceed 500 person-days.

The first test has two conditions joined by and. A 35-day project with a peak of 12 people does not meet that test, although it might meet the person-day test. The second test uses exceed, so a total of exactly 500 person-days does not itself cross it. These thresholds should be calculated from the planned construction phase and updated if the programme changes. Do not confuse working days with calendar days or add together every worker who ever visited site when assessing simultaneous presence.

A person-day is one person's construction work for one day. For a simple estimate, multiply the number of people working each day by the days they work and add the results. For example, 10 people working 40 days would be 400 person-days; this alone would not meet either threshold unless the schedule includes a higher workforce peak or other days that raise the total above 500. The example is arithmetic, not a decision about a real project with changing phases or subcontractors.

Who submits and when?

The client must notify HSE as soon as practicable and before the construction phase begins. A client may delegate administrative preparation, but should ensure the information is accurate and the notification is made. Check the domestic-client provisions separately, as CDM transfers many client duties on domestic projects under regulation 7. Do not assume the principal contractor is always the statutory notifying party.

The information includes the client, principal designer and principal contractor where applicable, project address, description, planned dates, estimated duration and workforce, and planned number of contractors. Use the live HSE form for its current fields. HSE has changed the form service, so avoid using an old bookmarked form or copying a screenshot into a permanent procedure.

If key particulars change, update the notification. Keep a copy of the current notice in the project records. Regulation 6 also requires a copy to be displayed in the construction site office, where it can be read by any worker engaged in the construction work. If there is no site office, review the regulatory wording and site arrangement before assuming that a noticeboard elsewhere is equivalent.

Appointment and F10 are separate questions

Principal designer and principal contractor appointments are generally required when more than one contractor is, or is reasonably foreseeable to be, involved. This is a different test from F10 notification. A project with two contractors may need both principal roles even if it is short and never meets the F10 thresholds. See the CDM 2015 guide for the duty-holder roles and use the CDM duty checker to map roles.

A reliable F10 workflow

At project planning, record the scheduled construction days, peak simultaneous workforce, and estimated person-days. Recheck these when the contract programme or sequence changes. Confirm who the client is and who will submit the official form. Review the information with the appointed principal designer and principal contractor where those roles exist. Submit through HSE's current service, retain confirmation, and display the current notice where required. Include a trigger in the project change process for revised dates, workforce or appointments.

Complys is not represented here as an F10 submission channel. Use HSE's service to notify. For the wider project document workflow, review the construction compliance software page and assess whether it fits your project records. The construction phase plan page covers a separate core project document.

General information, not legal advice. Verify current requirements against the primary sources linked above.