Compliance Tools · Scheme Comparison
CHAS vs SMAS vs Constructionline vs SafeContractor — What's the Difference?
All four are UK contractor pre-qualification schemes used by buyers, councils, housing associations, and principal contractors. But they are not the same. Here's what you need to know.
Scheme Comparison
| Scheme | Type | H&S Focus | Wider Compliance | Who Accepts It | Approx Cost | SSIP |
|---|---|---|---|---|---|---|
| CHAS | H&S Pre-qual | Core | No | Widespread | ~£300–500/yr | Yes |
| SMAS Worksafe | H&S Pre-qual | Core | No | Widespread | ~£200–400/yr | Yes |
| Constructionline Silver | PQQ Database | Core | Partial | Major buyers | ~£300–600/yr | Yes |
| Constructionline Gold/CAS | PQQ Database | Full | Yes | Tier 1 / public sector | ~£500–900/yr | Yes |
| SafeContractor | H&S Pre-qual | Core+ | Partial | FM / widespread | ~£300–500/yr | Yes |
| NAS Basic | Independent Cert | Core | Partial | NAS buyers | £749/yr | Independent |
| NAS Silver | Independent Cert | Full | Yes | NAS buyers | £950/yr | Independent |
| NAS Gold | Independent Cert | Yes | Yes | NAS buyers | £1,150/yr | Independent |
* Costs are approximate and may vary. Always check directly with the scheme for current pricing. NAS costs are illustrative.
Where Contractors Get Confused
SSIP Mutual Recognition
CHAS and SMAS are both SSIP members, meaning their H&S assessment is accepted in lieu of the other. For H&S pre-qualification, they are largely interchangeable with most principal contractors.
Constructionline Gold is significantly more
Constructionline Gold (Common Assessment Standard) requires environmental, quality, modern slavery, anti-bribery, and financial evidence — far beyond the SSIP core standard.
NAS is independent
NAS is not an SSIP member and is independently assessed. It includes legislative compliance requirements beyond the SSIP core, with three tiers reflecting increasing scope.
Why Checking Your Documents First Makes Sense
Every one of these schemes costs money to apply to — and most charge whether you pass or fail. Knowing what each scheme asks for before you apply avoids wasted fees. NAS publishes its requirements for every tier, and every finding comes with a clear explanation of what evidence closes it.
Ready to Get Certified?
See exactly what each NAS tier asks for, then apply online. Every application is checked against the published NAS requirements and signed off by a qualified assessor.
Published prices · Clear feedback on every finding · Live public register
NAS is an independent certification scheme. Acceptance of any certificate is decided by each buyer; NAS does not guarantee acceptance by any particular client or scheme.