Evidence-Based · ISO/IEC 17021 Aligned

Contractor Certification UK

NAS is independent, evidence-based contractor certification for UK businesses. Qualified assessors review your actual compliance documents — not a self-declaration form — and issue a certificate confirming your evidence meets the NAS standard.

Quick Answer

What is contractor certification in the UK?

Contractor certification in the UK is a formal process where an independent body reviews a contractor's compliance evidence — including health and safety, insurance, RAMS, workforce records and operational controls — and issues a certificate confirming the evidence meets a defined standard. NAS is evidence-based: assessors review actual documents, not self-declarations. Certified businesses are listed on the public NAS Certified Business Register.

Four NAS Certification Tiers

NAS Basic

£349/yr

Health and safety policy and arrangements, risk assessments and method statements, COSHH, CDM duties, training, insurance and subcontractor checks — the SSIP core criteria.

NAS Bronze

£749/yr

Everything in Basic plus legal identity and licences, employers’ liability insurance, data protection, equality, complaints handling, employment terms and right-to-work checks.

NAS Silver

£950/yr

Everything in Bronze plus environmental and waste management, quality and corrective action, governance and conflicts of interest, competition law, pensions, working time and subcontractor approval.

NAS Gold

£1,150/yr

Everything in Silver plus 13 procurement modules: financial standing, anti-bribery and integrity disclosures, tax status, cyber security, ethical supply chain, sustainability and Building Safety Act readiness.

Full pricing breakdown →

What NAS Certification Includes

Independent evidence review by an assessor
A separate certification decision
NAS certificate with a unique certificate number
Public register listing, searchable by buyers
Certificate check by number on the Verify page
Annual renewal with a fresh evidence review
Reminders before your certificate and documents expire
Flat fees with loyalty discounts from year 2

Contractor Certification UK — FAQs

About NAS: The National Assurance Standard (NAS) is an independent, evidence-based certification scheme for UK contractors and SMEs. NAS operates in alignment with ISO/IEC 17021 principles and is working towards UKAS accreditation. NAS is not a membership scheme — certification requires submission and independent review of actual compliance documents. NAS does not endorse or guarantee the ongoing compliance of certified businesses; certification reflects the evidence reviewed at the time of assessment.