Contractor prequalification checklist (UK)

The short answer

Before you appoint a contractor, CDM 2015 expects you to take reasonable steps to check they have the skills, knowledge, experience and organisational capability for the work. In practice that means asking for company details, insurance, a health and safety policy, risk assessments, any accreditation, evidence of their people's competence and their track record. HSE's guidance is clear that the checks should be proportionate to the risk, and that excessive or duplicated paperwork should be avoided.

What does the law expect when you appoint a contractor?

Regulation 8 of the Construction (Design and Management) Regulations 2015 says that a contractor appointed to a project must have “the skills, knowledge and experience, and, if they are an organisation, the organisational capability” to do the work in a way that secures health and safety. Regulation 8(3) puts a matching duty on whoever makes the appointment: they must take reasonable steps to satisfy themselves that the contractor meets that standard.

HSE's guidance on the Regulations, L153 Managing health and safety in construction, explains what “reasonable steps” means. Enquiries should be “sensible and proportionate”, and “excessive or duplicated paperwork should be avoided because it can distract attention from the practical management of risks” (paragraph 60). It also says you should check that the contractor has enough experience and a good record of managing the risks involved, ideally at the final stage before the appointment is made (paragraph 61).

HSE's HSG159 Managing contractors puts it plainly: “the depth of questioning needs to be tailored to the risks of the job”.

Company details and Companies House

Ask for the registered company name and number, the registered office and a named contact, then check them on Companies House's Search the register service. It shows each company's status, its filing history and its officers, and lets you search for disqualified directors.

Is the company active, or is it in liquidation, administration or being struck off?
Are its accounts and confirmation statement up to date?
Who are the directors, and has any been disqualified?

Which insurance should you ask for?

Employers' liability (compulsory)

Under the Employers' Liability (Compulsory Insurance) Act 1969, an employer must hold employers' liability insurance. GOV.UK states that the cover must be for at least £5 million and come from an authorised insurer (you can check the Financial Conduct Authority register). There are exemptions, for example where a business employs only family members. HSENI notes that while £5 million is the legal minimum, many insurers give a minimum of £10 million.

Public liability

Public liability insurance covers claims from third parties such as members of the public, clients and customers. It is not compulsory in the way employers' liability is, but, as West Sussex County Council's guide notes, many customers require proof of it before awarding work.

Professional indemnity and contractors' all risks

Ask for professional indemnity cover where the contractor will carry out design, and for contractors' all risks cover where they will be responsible for the works themselves.

There is no single “right” level of cover beyond the £5 million legal minimum for employers' liability. Set the limits you require in your requirement sets according to the work and its risk, and state them clearly so contractors know what to provide.

For every policy, check the insured name, the limit of indemnity, the type of work covered and the expiry date.

Health and safety policy and risk assessments

Section 2(3) of the Health and Safety at Work etc. Act 1974 requires employers to prepare a written statement of their health and safety policy, with the organisation and arrangements for carrying it out, and to bring it to the notice of their employees. HSE explains that a business with five or more employees must write its policy down; one with fewer doesn't have to, although it is useful to do so.

HSG159 warns that “companies often ask for contractors' health and safety policies but rarely do anything with them”. Read it: a good policy names who is responsible for what and describes the arrangements for putting it into practice.

Under regulation 3 of the Management of Health and Safety at Work Regulations 1999, employers must assess the risks of their work, and those with five or more employees must record the significant findings. At prequalification, an example risk assessment for the type of work you are buying is usually enough. Job-specific risk assessments and method statements (RAMS) belong at the work-package stage, once the scope is known. For high-risk activities, see our permit to work guide.

Should you require SSIP, CAS or another accreditation?

Many clients ask for a certificate from a Safety Schemes in Procurement (SSIP) member scheme or for Build UK's Common Assessment Standard (CAS). L153 describes SSIP assessment as “one way a designer or contractor can demonstrate organisational capability at the pre-qualification stage of the appointment process, but not the only way”. It adds that the law does not require any business to use a third party, and that it is equally acceptable for a business to assess its own capability and supply the documents itself (paragraphs 64–65).

The SSIP Forum notes that BSI formally withdrew PAS 91 in April 2023. CAS includes the key questions from PAS 91, and central government and public sector bodies are directed to use it under Procurement Policy Notice 03/24.

If you require a certificate, record its number, scheme and expiry date. Our guides explain what SSIP, PAS 91 and CAS each cover and what the main schemes charge contractors.

How do you check the competence of the people doing the work?

A company certificate tells you about the organisation. It doesn't tell you about the operative who arrives on Monday. HSG159 suggests asking who will supervise and manage the work and what their experience and training is, and deciding how much evidence you need to back that up.

Cards and tickets for the trades involved: CSCS, CPCS or NPORS for plant, IPAF for MEWPs, ECS for electricians, CCNSG safety passports and similar. See checking CSCS and competency cards.
Training records for the specific tasks, with dates and expiry.
Supervision: who will be in charge on site, and their experience of this kind of work.
Professional body membership for designers and consultants, which L153 says should be given “due weight” (paragraph 62).

Track record, enforcement and subcontracting

Ask for references from similar jobs and for a summary of incidents the contractor has reported under RIDDOR. HSG159 includes the question “Has HSE ever taken action against your activities?”. You can check the answer yourself: HSE's public register of enforcement notices lists improvement and prohibition notices. They are published five weeks after they are served and stay on the register for five years. Some notices are temporarily on a separate list while HSE updates the register, so check both.

Ask whether the contractor will subcontract and how they check their subcontractors: the regulation 8(3) duty applies to them too. HSG159 suggests making clear that main contractors must manage their subcontractors and make sure they follow your site rules.

The checklist at a glance

A prequalification checklist, with the risk tier at which each item is typically asked for
Item	Why	What good looks like	Risk tier
Company name, number, address	Know who you're contracting with	Matches Companies House; status active; filings up to date	All
Employers' liability insurance	Compulsory for employers (1969 Act)	At least £5m, authorised insurer, insured name matches, in date	All (if they employ staff)
Public liability insurance	Third-party injury and damage	At or above your stated limit, covers the work, in date	All
Professional indemnity / contractors' all risks	Design work; responsibility for the works	Limit and scope match the contract	Where relevant
Health and safety policy	HSWA 1974 s2(3)	Written if 5+ employees; names responsibilities and arrangements; reviewed recently	All
Example risk assessment / method statement	MHSWR 1999 reg 3	Specific to the type of work, not generic	Medium and high
SSIP, CAS or equivalent	Independent check of organisational capability	Certificate number, scheme and expiry recorded	As your policy requires
People's cards and training	CDM 2015 reg 8 competence	Right card for each task, in date, details recorded	Medium and high
Incident and enforcement history	Track record (L153 para 61)	RIDDOR summary; HSE notices register checked	High
Subcontracting arrangements	Duty passes down the chain	How subcontractors are vetted and managed	Medium and high

How do you review it in proportion to the risk?

Group the work you buy into a small number of risk tiers and set what each tier needs. For example:

Low: a one-day visit to service office equipment. Company details, insurance and a policy.
Medium: routine maintenance or fit-out trades. Add an example risk assessment, supervisor details and the operatives' cards.
High: work at height, hot work, confined spaces, lifting operations, demolition or electrical work. Add method statements, track record checks, subcontracting arrangements and closer review of every person's competence.

Then decide what you will verify and what you will accept as stated. Insurance certificates, Companies House status and card details are quick to check.

Prequalification isn't a one-off. Record expiry dates when you approve a document, remind the contractor before it lapses, re-check company status regularly, and revisit the tier when the scope of work changes.

How Assured Contractors helps

In Assured Contractors you set requirement sets for each kind of work and risk tier. You send contractors your company code or invite link; they join free (no joining, annual or per-client fee), are connected to you straight away and upload their documents once: insurance with expiry dates, policies and certificates, including SSIP or CAS. Each client reviews them on its own terms. Companies House status is monitored, reminders go out before documents expire, and each contractor's status (Ready, Action required or Blocked) comes with a “Why?” list of reasons. See contractor prequalification and worker competence.

Questions

Is employers' liability insurance a legal requirement for contractors?

Yes, for any business that employs people, with limited exemptions such as businesses that employ only close family members. GOV.UK says cover must be for at least £5 million from an authorised insurer, and the certificate must be displayed where employees can see it, which can be electronically.

Do I have to require SSIP from my contractors?

No. HSE's L153 guidance says SSIP assessment is one way to show organisational capability but not the only way, and that a contractor can equally assess its own capability and supply the documents directly. Many clients still require SSIP or CAS as company policy. If you do, record the certificate and its expiry like any other document.

Does a contractor with fewer than five employees need a written health and safety policy?

Not by law. HSE says businesses with five or more employees must write their policy down. Smaller businesses don't have to, though it is useful. The same five-employee threshold applies to recording the significant findings of risk assessments.

How often should contractor prequalification be repeated?

Track each document's expiry rather than redoing everything on a fixed cycle. Insurance usually renews every year, and cards and accreditation certificates have their own expiry dates. Re-check company status regularly, and review the whole record when the scope of work or its risk changes.

Where can I check whether HSE has taken enforcement action against a contractor?

HSE publishes improvement and prohibition notices on its public register of enforcement notices. Notices appear five weeks after they are served and stay on the register for five years. While HSE updates the register, some notices are on a temporary list, so check both.

Sources

Checked 11 November 2026. Legislation links go to legislation.gov.uk; guidance links to the publisher's own pages.

This guide is general information, not legal advice. Check the current legislation and guidance for your own site and work.

Contractor prequalification checklist: what to ask for and how to review it