PQQ Guides & Resources | Liaison Systems Insights

25 May 2026

Common Assessment Standard vs SSIP: What's the Difference?

The Common Assessment Standard (CAS) and SSIP (Safety Schemes in Procurement) are often confused, but they cover very different ground. SSIP deals only with health and safety competence and provides mutual recognition between H&S assessment schemes. CAS is far broader - a full pre-qualification framework covering 10 areas, of which health and safety is just one. CHAS and Constructionline are not standards at all; they are assessment bodies that can certify you against both SSIP and CAS. This guide explains how they relate, where they overlap, and which your business actually needs.

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25 May 2026

PPN 03/24 Explained: What It Means for Construction Pre-Qualification

Procurement Policy Note PPN 03/24 is UK Government guidance, issued in March 2024, that directs public sector contracting authorities to use the Common Assessment Standard (CAS) when pre-qualifying suppliers for construction works. For public sector projects above the £5.337 million threshold, CAS is now the preferred pre-qualification method, replacing PAS 91. PPN 03/24 is guidance to buyers rather than a law imposed on contractors - but in practice it means CAS compliance is increasingly a gate to public sector construction work. This guide explains what PPN 03/24 says, who it affects and what suppliers and buyers should do about it.

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25 May 2026

The Common Assessment Standard Checklist: All 10 Sections Explained

The Common Assessment Standard (CAS) question set is divided into 10 sections, each covering a different area of compliance and risk management. To pass your audit, you need the right evidence ready for each one - not just a yes/no answer. This checklist explains all 10 CAS sections, what each looks for, and the documents you should have to hand before you start. Use it to gap-check your own readiness, then download our free CAS checklist to track your progress section by section.

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25 May 2026

What Is the Common Assessment Standard (CAS)? A Complete Guide

The Common Assessment Standard (CAS) is the UK construction industry's standardised pre-qualification questionnaire (PQQ), developed by Build UK. It replaced PAS 91 - which was withdrawn by BSI in April 2023 and is now the preferred pre-qualification method for public sector construction procurement under Procurement Policy Note PPN 03/24. CAS uses a single industry-agreed question set, divided into 10 sections, that lets a supplier prove their capability and compliance once and share it with multiple buyers. The current Version 5 (published 1 July 2025) made the Building Safety section mandatory. Around 21,000 suppliers now hold CAS certification through one of seven Recognised Assessment Bodies.

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25 May 2026

How to Get Common Assessment Standard Certified: A Step-by-Step Guide for Suppliers

To get Common Assessment Standard (CAS) certified, you apply to one of the seven Build UK Recognised Assessment Bodies - such as Constructionline, CHAS or Compliance Chain - complete the industry-agreed question set, submit supporting evidence and pass either a desktop or site-based audit. Certification lasts one year. Because of CAS data sharing, you only need to be certified once and can then share the result with other bodies and clients. This guide walks through the process step by step, explains the two audit levels, and shows how to prepare so you pass first time.

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23 Mar 2026

How to Prepare for a PQQ (Supplier Side Guide for 2026)

If you’re a supplier looking to win work in construction, completing a Pre-Qualification Questionnaire (PQQ) is often the first hurdle. But many suppliers fail at this stage, not because they lack capability, but because they don’t prepare properly. This guide walks you through exactly how to prepare for a PQQ, improve your success rate and avoid the most common mistakes.

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11 Feb 2026

What Is a Pre-Qualification Questionnaire (PQQ)? The Ultimate Guide (2026)

A Pre-Qualification Questionnaire (PQQ) is a structured assessment tool used by supply chains to screen potential suppliers and contractors before inviting them to tender or work on a project. It acts as the first gate in the procurement or tendering process, helping buyers shortlist capable, compliant and low-risk vendors while saving everyone time, effort and money.

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20 Oct 2025

What is PAS-91?

PAS-91 is a standardised set of questions designed to simply the pre-qualification process.

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29 Sep 2025

How to effectively manage your supply chain.

Supply Chain Management is the control of all suppliers working on a project. There are 4 main sections of Supply Chain Management: procurement, operations, distribution, and integration.

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22 Sep 2025

Why can a Pre-Construction Questionnaire (PCQ) Matter More Than a PQQ

In construction, most organisations are familiar with the Pre-Qualification Questionnaire (PQQ). It assesses a contractor’s general suitability, financial stability, health and safety policies, insurance and company credentials. But when it comes to pre-construction, a PQQ is not enough. A Pre-Construction Questionnaire (PCQ) goes further. It is project specific, designed to gather the operational, safety and competency information needed before work begins on a particular site. If a PQQ tells you whether a contractor can work in construction, a PCQ tells you whether they are ready to work on this project.

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