The Procurement Act 2023 is the biggest change to UK public procurement law in over a decade. It replaces the Public Contracts Regulations 2015, the Utilities Contracts Regulations 2015, and the Concession Contracts Regulations 2016 with a single, unified framework. For anyone involved in supplier management, whether you are a public sector buyer or a supplier bidding for government work, the Act changes how due diligence is conducted, what grounds exist for excluding suppliers, and how transparency is maintained throughout the procurement lifecycle.

This is not a minor update. The Act introduces new mandatory and discretionary exclusion grounds, a central debarment list, and a strengthened transparency regime that puts supplier assessment data into the public domain. If your organisation buys from or sells to the public sector, you need to understand what has changed.

New Exclusion Grounds

The 2015 regulations defined mandatory exclusion grounds largely around criminal convictions: bribery, fraud, money laundering, and certain other offences. The Procurement Act 2023 keeps those but expands the list.

Mandatory exclusion now includes suppliers convicted of offences under the Modern Slavery Act 2015, the Terrorism Act 2000, and offences relating to tax evasion under the Criminal Finances Act 2017. It also covers suppliers that have been found to have committed certain labour market offences, including those under the Employment Agencies Act 1973 and the National Minimum Wage Act 1998.

Discretionary exclusion grounds have been widened too. Contracting authorities can now exclude suppliers on the basis of poor performance on a previous public contract, where that poor performance led to termination, damages, or a settlement. They can also exclude on the basis of professional misconduct, which is defined more broadly than under the previous rules.

For supplier management teams, this means the scope of due diligence checks at the pre-qualification stage has expanded. You need to be assessing suppliers against a wider set of criteria, and you need the evidence to support your decisions.

The Central Debarment List

One of the most significant introductions is the central debarment list, maintained by the Cabinet Office. A supplier placed on this list is excluded from all public procurement above the relevant threshold, not just from the contracting authority that identified the issue.

This changes the landscape for supplier risk management. Previously, a supplier excluded by one contracting authority could continue to win work from others who were unaware of the issue. The debarment list creates a shared record that all public sector buyers must check.

For supplier management platforms, this creates a data point that should be checked during onboarding and at regular intervals during the supplier relationship. A supplier that appears on the debarment list after they have been onboarded represents a material risk that needs to be caught quickly, not at the next annual review.

Strengthened Transparency Requirements

The Act introduces a new transparency regime that requires contracting authorities to publish notices at key stages of the procurement process: when a contract is planned, when it is awarded, when it is modified, and when it ends. Pipeline notices give the market advance visibility of upcoming opportunities.

For supplier management, the transparency obligations extend to how you record and justify your supplier assessments. Decisions to exclude or include suppliers need to be documented with supporting evidence. The days of informal supplier selection based on existing relationships and undocumented assessments are over, at least for public procurement.

This has a direct impact on how you structure your supplier records. Assessment criteria, due diligence evidence, compliance questionnaire results, and risk scores all need to be recorded in a way that can be disclosed if challenged. An audit trail is no longer a nice-to-have. Under the Procurement Act 2023, it is an operational requirement.

What This Means for Your Due Diligence Process

If you are managing suppliers in a public sector context, or for private sector organisations that supply to the public sector, there are practical steps you should be taking now.

Review your exclusion screening. Your supplier onboarding and periodic review processes need to check against the expanded mandatory and discretionary grounds. This means asking specific questions about Modern Slavery Act compliance, tax evasion offences, labour market violations, and past contract performance with other public bodies. Generic compliance questionnaires that have not been updated since 2015 will not cover the new grounds.

Check the debarment list. Build a check against the central debarment list into your onboarding workflow and your periodic review cycle. A supplier's status can change at any point during the contract, so a one-off check at onboarding is not sufficient.

Document your assessments. Every supplier assessment decision, whether it results in approval, conditional approval, or exclusion, should be recorded with the evidence that supports it. Under the transparency regime, you may be required to justify these decisions publicly. A structured assessment record in your supplier management system is far more defensible than a note in someone's email.

Update your compliance packs. If you use questionnaire-based compliance assessments, review the questions against the new exclusion grounds. Ensure you are asking about the specific offences and circumstances that the Act identifies, not just generic compliance statements.

Brief your suppliers. Suppliers that bid for public sector work need to understand the new exclusion grounds and what they need to demonstrate. Proactive communication with your supply chain about what you will be asking and why helps maintain the relationship and avoids surprises during the assessment process.

Looking Ahead

The Procurement Act 2023 raises the bar for supplier due diligence in UK public procurement. Organisations that already run structured, evidence-based supplier assessment processes will find the transition manageable. Those relying on informal processes, outdated questionnaires, and undocumented decisions will need to catch up quickly.

The underlying principle is straightforward: public money should be spent with suppliers that meet clear standards of conduct, and the evidence for those decisions should be transparent and auditable. A supplier management platform that captures compliance data, tracks risk, and maintains an audit trail puts you in a strong position to meet these requirements.

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