Based on common PSL (Preferred Supplier List) practices across industries, suppliers are usually asked to demonstrate compliance with a few key mandatory requirements. Here’s a comprehensive breakdown of the most frequently requested items:

Insurance

Most PSLs require evidence of adequate insurance coverage to protect both the supplier and the client. Common types include:

Public Liability Insurance – protects against claims from third parties for injury or property damage.

Professional Indemnity Insurance – essential for service providers or consultants, covering mistakes or negligent advice.

Employers’ Liability Insurance – legally required in the UK if you employ staff.

Product Liability Insurance – relevant for suppliers delivering physical products.

Health & Safety Policies

Suppliers must demonstrate compliance with health and safety standards to reduce risks in the workplace. This often includes:

Written Health & Safety Policy (mandatory if you have five or more employees in the UK).

Evidence of risk assessments for projects or services.

Safety training records for staff where relevant.

Data Protection & Cybersecurity

Many PSLs now require evidence of how a supplier handles sensitive information:

GDPR compliance or data protection policies.

Cybersecurity measures if handling client data or operating online systems.

Accreditations & Certifications

Depending on the sector, PSLs often require suppliers to hold certain certifications or accreditations:

ISO Standards – e.g., ISO 9001 (Quality), ISO 14001 (Environmental), ISO 45001 (Health & Safety).

Sector-specific accreditations – e.g., Constructionline, CHAS, SafeContractor in construction, or CIPS membership for procurement.

Professional licenses – required for legal, financial, or regulated sectors.

Equality, Diversity & Sustainability Policies

Some organisations require suppliers to show:

Equality & Diversity policies to demonstrate fair employment practices.

Environmental or sustainability policies, particularly in public sector PSLs or for companies with strong ESG commitments.

Financial Stability

Certain PSLs may ask for evidence that your business is financially stable:

Audited accounts or annual financial statements.

Bank references or credit checks.

References & Past Performance

Although not a “policy,” many PSLs require references or evidence of past projects to verify reliability and competence.

Summary.

The most common mandatory requirements across PSLs are:

Insurance (Public Liability, Professional Indemnity, Employers’ Liability)

Health & Safety Policies and risk assessments

Data Protection / GDPR compliance

Relevant accreditations and professional licenses

Equality, Diversity, and Sustainability policies

Evidence of financial stability

References or proof of past work