Clear, practical guides on NAS certification, contractor compliance and procurement readiness for UK contractors and buyers.
A clear explanation of what certification and accreditation mean, how they differ, and what ISO/IEC 17021 alignment means for NRTAUK NAS.
A detailed comparison of the four NAS certification tiers — what each covers, what evidence is assessed, and which tier is right for your business.
Practical steps UK contractors can take to organise compliance evidence, achieve certification and present themselves as procurement-ready to buyers.
An explanation of approved contractor registers — what they are, how buyers use them, and how the NAS Certified Business Register works.
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.