🏗️ For Main Contractors & Principal Contractors

Require NAS-Certified Subcontractors
On Every Project You Deliver.

As principal contractor, you own the compliance of your entire supply chain under CDM Regulations. NAS gives you independently assessed, publicly verifiable subcontractor compliance — covering H&S, RIDDOR, Modern Slavery, Environmental Protection, and Public Contracts Regulations — so you can build with confidence.

Free
Register Verification
22
Laws Covered at Gold
ISO 17021
Aligned Assessment
100%
Independent Review

Why Require NAS From Your Subcontractors?

Under CDM 2015, you are responsible for the health, safety, and legal compliance of every subcontractor on your site. A non-compliant subcontractor incident isn't just their problem — it is yours. Independent verification matters.

The Risk Without It

CDM Regulation 4 places a legal duty on you to satisfy yourself that all subcontractors have the skills, knowledge, and experience to carry out their work safely and compliantly
RIDDOR reportable incidents involving subcontractors without evidenced H&S compliance result in HSE investigation of the principal contractor
Modern Slavery Act non-compliance in your supply chain exposes your organisation to reputational and legal liability as the contracting body
Environmental Protection Act breaches by subcontractors on your site — illegal waste disposal, spillages — can trigger enforcement against you as site controller
Public Contracts Regulations require proportionate supply chain due diligence on public sector projects — self-declaration alone won't pass scrutiny
A non-compliant subcontractor on a live project can halt work, trigger client disputes, and damage your approved supplier status

Why Requiring NAS Protects You

NAS-certified subcontractors have independently evidenced H&S, RIDDOR, and Modern Slavery compliance — documented and verifiable by your teams, not just procurement
Certified subcontractors share a live profile link — see current insurance, assessor-verified documents, and confidence score in real time. No chasing PDFs or last year's certificates
See named operatives and their CSCS, IPAF, CPCS, Gas Safe, and trade cards with live Green / Amber / Red compliance status — verify before they arrive on site
The NAS Supply Chain Portal gives you one dashboard for all certified subcontractors — searchable by trade, tier, location, and compliance status
NAS Gold covers Public Contracts Regulations and Environmental Protection Act — essential for public sector principal contractor work
Annual renewal means you're always looking at current compliance status, not a one-off registration snapshot — and expired credentials are flagged immediately on the live profile

How NAS Works For You

Independent, evidence-based contractor certification you can rely on.

Instant Register Search

Verify any subcontractor free on the NAS public register — by name or certificate number, no login required. Confirm current NAS tier and certificate status before they step on site.

CDM-Ready Evidence

NAS certification provides independently reviewed, documented evidence of subcontractor compliance — exactly what CDM Regulation 4 requires you to hold on file for every subcontractor.

Live Compliance Profile — Not a Static Certificate

Certified subcontractors share a secure link to their live profile. You see current insurance status, assessor-verified documents, confidence score, and named operative cards — updated in real time, not at point of issue.

Named Workforce Verification

See named operatives the subcontractor has registered — CSCS, IPAF, CPCS, Gas Safe, and trade cards — with live Green / Amber / Red status per individual. Verify before they arrive, not after an incident.

Traffic Light Expiry Alerts

Documents, insurance, and certifications display Green (current), Amber (expiring within 30 days), or Red (expired) on the shared profile. No chasing — the risk is visible instantly.

Supply Chain Portal for Main Contractors

Access the NAS Supply Chain Portal — a dedicated dashboard showing all your certified subcontractors, their live compliance status, confidence scores, and workforce data in one searchable view. No document requests needed.

Verify a Contractor Right Now

Search the NAS public register to instantly confirm any contractor's current certification status and tier — free, no login required.

Frequently Asked Questions

Raise Your Supply Chain Standard

Start requiring NAS certification from your contractors — independent, evidence-based, and publicly verifiable.

NAS TradeLink

Find Verified Main Contractor Contractors Instantly

NAS TradeLink gives procurement teams and main contractors direct access to a network of independently verified NAS-certified contractors. Post your requirement and receive ranked matches based on trade, location, certification tier, and real-time availability.

All contractors independently NAS-assessed — no self-declaration
Ranked matches by certification, insurance status & availability
View live compliance profiles before inviting to quote
Full audit trail of all procurement decisions
NAS TradeLink
Contractor Matching Network
NetworkNAS-certified only
VerificationIndependent assessment
MatchingReal-time ranked results
CoverageUK-wide
AccessVia Supply Chain Portal