Free tool

CDM dutyholder checker

Five questions and you get a map of who holds which duty on your project, including where the roles have landed by default if nobody was appointed.

Who is the client?

The client is whoever the work is being done for.

This tool gives general guidance from the answers you type. It is not legal advice about your project, and it cannot see your drawings or your site. Where a project is unusual the answer is a conversation rather than a checker. How we write this.

The five dutyholders

CDM 2015 works by giving named duties to five kinds of party. Every project has all of them in some form, even a small one, and the roles do not disappear when nobody is appointed. They move.

Clientappoints in writing, before work startspre-construction phasePrincipal designerconstruction phasePrincipal contractorthe informationDesignersContractors
The five CDM 2015 dutyholders, drawn as the information actually moves. The client appoints a principal designer and a principal contractor in writing before the construction phase begins. Each designer passes up the risks their design leaves behind, under regulation 9(3). The principal designer gathers that with the client's own information and hands it to the principal contractor for the construction phase plan, under regulation 12(3). The principal contractor passes down the parts of that plan each contractor needs.

Where the defaults come from

If nobody is appointedDomestic clientEveryone else
Principal designerRegulation 7(2): the designer in control of the pre-construction phaseRegulation 5(3): the client carries the duties
Principal contractorRegulation 7(2): the contractor in control of the construction phaseRegulation 5(4): the client carries the duties
Client dutiesRegulation 7(1): the principal contractor, or the principal designer by written agreementStay with the client. Not transferable

Written by Robbie Thompson, BA (Hons) Dip Arch, SMSTSLast reviewed 28 August 2026How we write this

Sources

  1. CDM 2015, regulation 5 legislation.gov.uk
  2. CDM 2015, regulation 7 legislation.gov.uk
  3. CDM 2015, regulation 9 legislation.gov.uk
  4. CDM 2015, regulation 12 legislation.gov.uk
  5. CDM 2015, regulation 15 legislation.gov.uk