Quick Answer
The NAS Certified Business Register is a publicly searchable register of all businesses that hold current NAS certification. Any buyer can search it by business name or trade to verify certification status, tier, certificate number and expiry date. It is updated in real time as certifications are issued, renewed or expire.
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.