Do I Need More Than One Accreditation Scheme? A Subcontractor's Decision Guide

TL;DR

For pure health and safety, you almost never need more than one SSIP-registered scheme — every SSIP member recognises every other through the "Deem to Satisfy" agreement, confirmed by HSE guidance. You DO need a second accreditation when a client demands something SSIP doesn't cover: Constructionline Gold or Platinum, the Common Assessment Standard (CAS), or a client-specific PQQ that asks about finance, modern slavery, environmental management or quality systems. In practice the most common "stack" for a UK subcontractor in 2026 is one SSIP scheme (CHAS, SMAS, Acclaim or similar) plus Constructionline Gold — because Gold delivers the CAS that main contractors like VINCI, Kier, BAM, Wates and Balfour Beatty require, on top of the SSIP. If your work is purely sub-sub-contracting for one small main contractor who only asks for SSIP, stop at one.

If you've just won a second client and they're asking for a different accreditation to the one you already hold, the question hits straight away: do I need more than one accreditation scheme, or is the one I've got enough? For most small subcontractors the honest answer is "one is enough" — but there's a real subset of jobs where you genuinely need two, and it pays to know which camp you're in before you spend £600 on a scheme you didn't need.

What does "one accreditation" actually cover?

A single SSIP-registered scheme covers health and safety competence only. That's the bit that's mutually recognised. SSIP — Safety Schemes in Procurement — is the umbrella body whose member schemes (CHAS, SMAS Worksafe, Acclaim, Constructionline's Once For All H&S, Safety-Schemes-in-Procurement-approved certification bodies and so on) all assess against the same SSIP Core Criteria approved by the HSE.

The HSE is explicit on this point: as a supplier, you "should only need to be assessed against one of the SSIP member schemes" because your valid assessment is visible on the SSIP Portal to any future buyer (HSE: Health and safety conformity assessment schemes). If a buyer insists on a different scheme, you can apply for a Deem to Satisfy (DtS) certificate that ports your existing approval across, usually at a fraction of a full assessment fee.

The trap is assuming this mutual recognition stretches further than it does. It doesn't cover anything that isn't health and safety. Finance checks, modern slavery, anti-bribery, environmental management, quality systems, EDI policies, information security, Building Safety Act questions — none of those sit inside SSIP's remit. The moment a client wants any of those verified, you're outside the DtS bubble.

When is one accreditation genuinely enough?

One SSIP-registered scheme is enough if every client you work for is asking only for proof of H&S competence. In practice that means:

• You're a sub-sub-contractor working for a single main contractor who lists "SSIP" (or a named SSIP scheme like CHAS or SMAS) and nothing else on their PQQ.
• You work for small or mid-sized private clients (e.g. fit-out, domestic refurb, smaller commercial) where the buyer just wants a current SSIP certificate.
• You work for a local authority on contracts below the public-sector PQQ thresholds where they accept any SSIP scheme.

In all three cases, pick the cheapest SSIP scheme that fits your trade and stop there. If a future buyer demands a different SSIP brand, apply for Deem to Satisfy.

When do you genuinely need two (or more)?

You genuinely need a second scheme — not just a second DtS passport — when a client requires verification of something SSIP doesn't assess. The four common triggers:

1. The client mandates Constructionline Gold (or Platinum)

Constructionline's own guidance confirms that SSIP is now bundled across Bronze, Silver, Gold and Platinum memberships, so Gold isn't "SSIP plus more SSIP" — it's SSIP plus an enhanced PQQ aligned to the Common Assessment Standard. The Gold supplier checklist covers financial credibility checks, modern slavery, anti-bribery, environmental management, quality, EDI and information security. None of that is part of an SSIP assessment.

Main contractors who routinely require Constructionline Gold include VINCI, Wates, BAM Construction, Kier and Balfour Beatty, according to Constructionline's own buyer list. If one of those is your client, holding only CHAS or SMAS won't get you through the gate, even though you're SSIP-certified. You need Constructionline as well — and you might as well go straight to Gold because Silver and Bronze don't satisfy the same buyers.

2. The client wants the Common Assessment Standard

CAS is the Build UK-developed question set that replaced PAS 91 after it was withdrawn by BSI in 2023. It's broader than SSIP — it includes the SSIP Core Criteria but also goes into corporate standing, environmental, quality, EDI and the Building Safety Act.

You can hold a CAS certification via either Constructionline (Gold = desktop CAS audit, Platinum = on-site CAS audit) or via CHAS Elite, or via other CAS-registered assessment bodies. If your client says "we need CAS", any one of those routes works. But your SSIP-only certificate doesn't.

For public-sector work above the threshold of around £5.337m, Procurement Policy Note 03/24 recommends CAS as the preferred PQQ — so larger local-authority and central-government contracts will increasingly funnel you to CAS regardless of which scheme you started with.

3. The client is a housing association or utility with its own PQQ

Large housing associations, water companies, network operators and Tier 1 utility contractors frequently run their own pre-qualification on top of (or instead of) a generic accreditation. Some accept CAS via Constructionline Gold and call it done; others bolt their own modules on top — fire safety competence, asbestos surveying, gas-safe trade verification, dynamic purchasing system (DPS) membership.

There's no clean rule here. Read the tender. If it says "SSIP plus our PQQ" and the PQQ asks for financials and modern slavery, you can't dodge it by adding a second SSIP scheme — you have to fill in their PQQ. If it says "Constructionline Gold or equivalent", an existing CAS certification (e.g. via CHAS Elite) is usually accepted.

4. A specific client insists on a specific SSIP brand

This is the one that feels like you need two SSIPs but doesn't. If you hold SMAS and a new main contractor's portal only accepts CHAS, don't pay for a full second SSIP assessment. Apply for CHAS Deem to Satisfy via the SSIP DtS process — a fraction of the cost, no full re-audit. The SSIP DtS chart on ssip.org.uk shows the typical reduced fee for each scheme.

Decision tree by client type

Use this as a starting point. Always confirm the exact wording on the client's PQQ — buyers vary.

What about "stacking" CHAS and Constructionline?

This comes up a lot: "Do I need CHAS and Constructionline?" The honest answer is that you generally don't need both for their H&S layer — that's duplication SSIP DtS exists to prevent. But you might end up with both for different reasons:

• You already had CHAS for H&S, and a new main contractor demands Constructionline Gold. You don't drop CHAS — you add a Constructionline membership. Constructionline Gold includes its own SSIP via Once For All H&S, so technically you'd then have two SSIP certificates running in parallel. Many subcontractors in this position let CHAS lapse at renewal and rely on Constructionline's bundled SSIP instead. Some keep CHAS because a different client specifically asks for it.
• You hold Constructionline Gold with its bundled SSIP, and a client requires a CHAS-branded certificate. You can use SSIP Deem to Satisfy to get a CHAS DtS certificate without redoing the H&S audit. You don't need full CHAS membership.

The residual duplication mutual recognition doesn't fix

This is the bit nobody likes to talk about. Even with SSIP DtS working perfectly, you still face three real pain points if you hold two or more schemes:

1. Re-uploading the same documents. Your H&S policy, RAMS templates, employers' liability certificate, insurance schedule, training matrix, accident book — every scheme asks for them, every scheme has its own portal, every scheme expires on its own date. Mutual recognition handles the H&S assessment, not the document upload pain.
2. Different renewal dates. Your SSIP scheme renews annually. Constructionline renews annually but on a different date based on when you joined. CAS validity sits inside that. If you hold three things, you're chasing three renewals.
3. The non-mutually-recognised tiers. Constructionline Gold, the Common Assessment Standard and client-specific PQQs all sit outside SSIP DtS. There is no mutual recognition for finance checks, modern slavery, EDI or the BSA modules — every assessor that wants them re-verifies them.

These gaps are why subcontractors who hold two schemes often complain that mutual recognition "didn't really save us much" — DtS solved the H&S audit, but everything else still had to be re-done.

A practical four-step check before adding a second scheme

1. 1
   Read the client's PQQ word for word. Does it say "SSIP or equivalent", "CHAS specifically", "Constructionline Gold", or "Common Assessment Standard"? The wording dictates the answer. Don't take a procurement officer's verbal "we need CHAS" as gospel — ask for it in writing.
2. 2
   Check what your current certificate already covers. If you hold SSIP from any scheme, you're covered for any other SSIP brand via DtS. If you hold Constructionline Gold, you already have CAS-aligned coverage plus a bundled SSIP.
3. 3
   Try Deem to Satisfy first. If the client just wants a different SSIP brand, a DtS certificate is typically a fraction of full membership. Apply to the second scheme with your current SSIP details — they'll issue the DtS without a full re-audit.
4. 4
   Only add a second full scheme when it covers something your current one genuinely doesn't — usually Constructionline Gold for CAS access, or a CAS-registered route via CHAS Elite. Don't pay for two full SSIPs when one + DtS does the same job.

Related guides on TradeComply

• SSIP mutual recognition and Deem to Satisfy, explained — how the DtS process actually works in practice.
• CHAS vs SafeContractor vs Constructionline — side-by-side comparison if you're picking your first scheme.
• Constructionline Gold vs Silver vs Bronze — what each tier actually verifies.
• The Common Assessment Standard question set — what's inside CAS that SSIP doesn't cover.
• Tracking accreditation renewal deadlines — the residual pain DtS doesn't fix.

Frequently Asked Questions

Do I need both CHAS and Constructionline?

Usually no. CHAS is an SSIP-registered H&S assessment; Constructionline (at Gold or above) is a broader PQQ that already includes an SSIP via Once For All Health & Safety. Most subcontractors hold one or the other, not both. The exception is if you have specific clients who explicitly demand each — in which case, hold one fully and use SSIP Deem to Satisfy to bridge to the other.

Can I hold two SSIP certificates at the same time?

Yes, you can — but there's rarely a good reason to pay for two full assessments. The SSIP Deem to Satisfy process exists precisely so you don't have to. If a buyer insists on a specific SSIP brand and your current scheme is different, apply for DtS rather than a full second membership. HSE guidance explicitly says suppliers should only need to be assessed against one SSIP member scheme.

Does Constructionline Gold include SSIP?

Yes. Constructionline confirms that SSIP is now bundled across Bronze, Silver, Gold and Platinum memberships via Once For All Health & Safety, or via Deem to Satisfy if you already hold an SSIP elsewhere. So if a client wants "Gold plus SSIP", a single Constructionline Gold membership covers both. You don't need a separate CHAS or SMAS on top.

What's the cheapest way to satisfy two clients who ask for different schemes?

Hold one full SSIP scheme (pick the cheapest that fits your trade and turnover) and use SSIP Deem to Satisfy to issue passport certificates to any other SSIP brand a client asks for. The DtS fee is typically a small fraction of a full membership. Only pay for a second full scheme when the second client actually wants something outside SSIP's scope — usually CAS or Constructionline Gold.

Will the Common Assessment Standard replace SSIP?

No, they cover different things. CAS is a broader pre-qualification question set covering corporate standing, finance, environmental, quality, EDI, building safety and health & safety. SSIP is the H&S-only umbrella that CAS's health and safety questions are aligned to. You'll usually hold both: CAS via Constructionline Gold or CHAS Elite, and SSIP as the underlying H&S certification (which is normally bundled inside the same membership).