Supplier Verification You Can
Actually Evidence
NAS gives procurement teams, supply chain managers, and principal contractors a public register of independently reviewed UK businesses — supporting consistent, structured contractor due diligence.
Ask your suppliers whether they hold NAS certification. Check the public register instantly, at no cost.
Why Procurement Teams Need More Than Paperwork
Reviewing suppliers consistently is one of procurement's most persistent challenges. Businesses submit varying quality of documentation, standards differ between organisations, and there is rarely a structured baseline for comparison.
Self-declarations and basic policy checklists are easy to produce but difficult to evaluate. Without a structured third-party review framework, procurement teams are left making judgement calls on evidence that hasn't been independently assessed.
NAS provides an independent, evidence-based certification framework that gives procurement teams a credible reference point — one backed by structured document review, independent assessors, and formal certification decisions.
Structured Evidence Review
Every NAS certification is supported by reviewed documentation, not self-declaration.
Independent Assessment
Assessors operate independently from commercial interests. Decisions are made impartially.
Public Register
A freely accessible public register of certified UK businesses, searchable by procurement teams.
Consistent Baseline
Certification against the same structured criteria, applied consistently across all applicants.
What NAS Helps You Review
NAS certification is evidence-based. Here is what the assessment process examines across each tier.
Business Documentation
- Company policies and procedures
- Health & safety documentation
- Risk management evidence
- Employment and governance records
Business Structure & Credibility
- Registered business verification
- Operational structure evidence
- Business maturity indicators
- Governance and oversight records
Compliance & Operational Standards
- Insurance and legal compliance
- Staff training and competence
- Ethical business conduct evidence
- Quality and operational controls
Certification criteria vary by tier (Basic, Bronze, Silver and Gold). Higher tiers require more extensive evidence across governance, ethics, and operational management. Learn how the process works →
How Buyers Can Use NAS
Using NAS within your supplier review process is straightforward. Here are three practical ways procurement teams engage with NAS.
Check the Public Register
Visit the NAS Certified Business Register and search for any business. Certificate status, tier, and issue date are all publicly visible at no cost.
Ask Suppliers Directly
Add a simple question to your supplier questionnaire: "Do you hold NAS certification?" Suppliers can share their certificate number for independent verification.
Include as Part of Supplier Review
Use NAS certification as one component within your broader supplier onboarding, tender evaluation, or supply chain review framework.
Why This Matters for Contractor Onboarding
Consistent supplier qualification requires a reliable framework. NAS provides procurement teams with a structured, independently assessed reference point that adds credibility to contractor review without replacing your existing process.
Consistency Across Reviews
All NAS-certified businesses have been assessed against the same structured criteria. This supports a more consistent approach to comparing suppliers.
Visibility and Transparency
The public register is freely accessible. You can verify a business's certification status independently, without contacting the business directly.
Structured Evidence Standard
NAS certification is not self-declared. Evidence is reviewed by independent assessors, providing a more robust foundation than documentation alone.
Supports Existing Frameworks
NAS is designed to complement — not replace — your existing due diligence, procurement policies, and statutory compliance requirements.