• What supplier exclusion means and when it applies to your business
• The difference between exclusion and debarment under the Procurement Act 2023
• How the UK Debarment Register works and what appearing on it means in practice
• The mandatory and discretionary grounds that can bar you from bidding for public contracts
• What Assessment of Contract Performance Notices are and why they matter for your future eligibility
• Practical steps to protect your compliance record and stay competitive as a UK supplier
The UK public sector spends over £434 billion a year on goods and services, according to Cabinet Office data published in July 2025. Access to that market represents a significant revenue opportunity for thousands of UK businesses — but not every supplier is eligible to bid. Supplier exclusion and debarment rules determine who can and cannot compete for government contracts, and the Procurement Act 2023, which came into force on 24 February 2025, has significantly changed how those rules work. Many businesses only encounter these rules for the first time after an issue has already arisen — by which point the consequences can be difficult to reverse. This guide explains what UK businesses need to know before that happens.
Why Supplier Exclusion and Debarment Matter in UK Procurement
Competing for public sector contracts is not simply a matter of submitting the strongest bid. Before any contracting authority evaluates your proposal on its merits, it first assesses your eligibility to bid at all. Supplier exclusion is the mechanism by which organisations are assessed — and potentially removed — from procurement processes on the basis of their conduct, compliance record, or financial standing, within the framework of public procurement and the procurement regime that governs supplier eligibility.
The stakes are high. With direct public sector procurement totalling £249 billion in 2024/25 (Cabinet Office, July 2025), being excluded from even a single major framework or tender can have serious revenue consequences. For businesses that rely on public sector contracts, a formal exclusion or appearance on the Debarment Register can affect participation in procurement exercises and eligibility for awarding contracts across central government — not just the one where the issue arose.
Understanding the grounds for supplier exclusion, and knowing how the Debarment Register operates, is now a fundamental part of running a compliant and competitive public sector supply business.
What Is Supplier Exclusion? Understanding the Core Concept
Supplier exclusion is the process by which a contracting authority determines that a business is ineligible to participate in a specific procurement. Under the Procurement Act 2023, contracting authorities are required to assess whether any exclusion grounds apply to a supplier before awarding a contract or allowing them to participate in a competitive procedure. The process and criteria for excluding suppliers from covered procurements are governed by risk-based frameworks, which provide both mandatory and discretionary grounds for exclusion.
Importantly, exclusion is not a single outcome — it depends on which type of ground applies. The Act distinguishes between two categories of suppliers: a supplier may be classified as an ‘excluded or excludable supplier’ depending on the grounds that apply. An excluded supplier has triggered a mandatory exclusion ground and must be removed from the process. An excludable supplier has triggered a discretionary ground and may be excluded, depending on the authority’s assessment of the circumstances.
Supplier exclusion can also apply at different points in the procurement lifecycle. It may arise at the bid stage, preventing a business from submitting a compliant tender for a particular procurement. In some circumstances, it can result in the termination of an existing contract where an exclusion ground is discovered during the period of performance. This means compliance is not a one-time checkbox — it is an ongoing obligation throughout the life of a public contract.
What Is Debarment and How Does It Differ From Exclusion?
Exclusion and debarment are related but distinct. Exclusion is applied by an individual contracting authority within a specific procurement process. Debarment, by contrast, is a formal, centrally managed status under the Procurement Act 2023 that applies across all public contracts in scope.
When a supplier is added to the Debarment Register, they are not simply excluded from one contract — they are barred from bidding for all in-scope central government contracts for the duration of their entry. The debarment list meaning, in practical terms, is a cross-government determination with legal force. This is a significant escalation from the per-procurement exclusion decisions that contracting authorities make individually.
Debarment decisions are made by a Minister of the Crown following a formal investigation. They are not automatic — a contracting authority that excludes a supplier does not automatically trigger debarment. However, contracting authorities are required to notify a Minister when they exclude a supplier, and that notification can initiate a Procurement Review Unit (PRU) investigation that may ultimately lead to debarment.
The UK Debarment Register — What It Is and How It Works
What Is a Debarment List?
The Debarment Register is a publicly accessible list maintained by the Cabinet Office under the Procurement Act 2023. Serving as the central debarment register for all covered procurements, it records suppliers and contractors excluded from participating in public procurement due to misconduct, such as cartel activity or competition law infringements. Understanding the debarment list meaning goes beyond thinking of it as a simple blacklist: it is a formal legal mechanism with defined criteria, an investigative process, and built-in supplier rights. The Procurement Act 2023 introduces both mandatory and discretionary exclusion grounds for suppliers, including participation in cartel activity and potential competition infringements. The list is published on GOV.UK and can be checked by any contracting authority — or by any supplier wanting to verify their own status.
Contracting authorities are expected to check the Debarment Register before allowing a supplier to participate in a procurement and before awarding a public contract. As a practical step, businesses should also check whether their own organisation — or any associated entity — appears on the register before submitting any public sector bid.
Who Gets Added to the Debarment Register?
Suppliers are not added to the list automatically. The process begins with an investigation led by either the Procurement Review Unit (PRU) or the National Security Unit for Procurement, depending on the nature of the exclusion ground. Investigations can be triggered by a referral from Welsh Ministers or a Northern Ireland department, by notification of exclusion from a contracting authority, or by the PRU acting on its own initiative.
When an investigation is opened, the supplier must be notified and given an opportunity to make representations. Suppliers may be asked to provide information during the investigation. Crucially, failure to cooperate is itself a mandatory exclusion ground — meaning that ignoring an investigation request can make a difficult situation significantly worse.
Before making a final decision, the investigating Minister must be satisfied that an exclusion ground applies and that the circumstances giving rise to it are continuing or likely to recur. Where both tests are met, the Minister can proceed with debarment — though they retain discretion not to do so where, for example, there is an overriding public interest in allowing the supplier to continue bidding.
How Long Does Debarment Last?
A supplier’s name can remain on the Debarment Register for up to five years. For mandatory exclusion grounds, that period runs from when the relevant event occurred. For discretionary grounds, it runs from when the Minister knew, or should reasonably have known, of the event.
Debarment is not necessarily permanent. Suppliers can apply for removal or revision of their entry where there has been a material change of circumstances. The Minister is also obliged to keep the register under review and must remove a supplier’s name if satisfied that the exclusion or debarment ground no longer applies.
What Are the Consequences of Appearing on the Debarment List?
The practical impact of appearing on the debarment list is significant. Where a supplier is listed for a mandatory exclusion ground, contracting authorities must not allow them to participate in a competitive procedure or be awarded public contracts — and must disregard any tender submitted. Suppliers on the debarment list are therefore ineligible to be awarded public contracts, effectively excluding them from public procurement processes. Where the listing relates to a discretionary ground, authorities retain some flexibility but are strongly encouraged by statutory guidance to exclude the supplier unless they have good reasons to proceed.
Beyond the direct loss of contract opportunities, appearing on the debarment list carries reputational consequences that extend beyond central government procurement. It signals to the wider market — including framework managers, local authorities, and private sector clients — that the supplier has been subject to a formal investigation and adverse determination.
What Are the Grounds for Supplier Exclusion Under the Procurement Act 2023?
The grounds for supplier exclusion under the Procurement Act 2023 are set out in Schedule 6 (mandatory) and Schedule 7 (discretionary) of the Act.
Mandatory Exclusion Grounds
Mandatory grounds require exclusion where the relevant circumstances are continuing or likely to recur. There is no authority discretion on this point — if the ground applies and the circumstances are ongoing, the supplier must be excluded. Mandatory grounds include conviction for bribery, fraud, or corruption offences; modern slavery and human trafficking offences; tax evasion offences; and terrorism-related offences.
Two new mandatory grounds not present in the previous Public Contracts Regulations 2015 are also introduced by the Act. The first covers cartel activity — suppliers found to have engaged in anti-competitive conduct following CMA guidance published in February 2025. The second covers deliberate tax penalties that have become payable since 25 February 2022. Additionally, failure to cooperate with a debarment investigation is itself a mandatory exclusion ground.
Discretionary Exclusion Grounds
Discretionary grounds give contracting authorities the flexibility to assess whether exclusion is appropriate in the circumstances. Key discretionary grounds include a sufficiently serious breach of a relevant contract — where that breach resulted in full or partial termination, an award of damages, or a settlement agreement. Other discretionary grounds encompass professional misconduct, labour misconduct, and serious labour misconduct, which refer to dishonest, improper, or severe violations related to employment practices and can lead to supplier exclusion even without a conviction. In addition, insolvency or financial distress, misrepresentation in a procurement process, a conflict of interest that cannot otherwise be remedied, breaches of environmental or labour law, and obtaining an unfair advantage through improper conduct are all included. Private utilities are subject to different rules regarding discretionary exclusion grounds compared to public sector entities.
Self-Cleaning — Can Excluded Suppliers Rehabilitate?
Yes. The Procurement Act 2023 retains and strengthens the concept of “self-cleaning” — a process through which a supplier can demonstrate that it has addressed the issue giving rise to the exclusion ground and that the circumstances are unlikely to recur.
The Act’s approach to self-cleaning is more flexible than the rigid three-test framework that applied under the PCR 2015. Contracting authorities must consider a broader range of factors, including the seriousness of the conduct, the credibility and timing of remediation steps taken, and whether future risk has been meaningfully addressed. Practical evidence of self-cleaning may include changes to personnel or management, new compliance procedures and training, or independent audits where proportionate.
Importantly, self-cleaning evidence should ideally be prepared proactively — before a procurement question is raised — and kept on file. Businesses that have identified a potential exclusion risk in their history are better served by documenting their remediation steps in advance than by assembling evidence reactively when a contracting authority raises a concern. It is for the supplier to proactively demonstrate self-cleaning to the satisfaction of the contracting authority assessing it.
What Is the Procedure for Supplier Exclusion?
The procedure for supplier exclusion typically follows these steps under the Procurement Act 2023. First, the contracting authority identifies a potential exclusion ground during the procurement process — through a supplier declaration, a third-party check, information that emerges during due diligence, or when individuals or businesses report concerns to the authority. Authorities may also provide confidential guidance to suppliers who seek advice about legal compliance or exclusion risks.
During due diligence, the authority should check for ongoing investigations, such as those listed on the CMA case list, and assess whether any connected person—such as beneficial owners, directors, or parent companies—may be relevant to the exclusion or self-cleaning assessment.
The supplier is then notified and given an opportunity to respond, including by providing self-cleaning evidence. Following that, the authority makes its exclusion decision, documenting its reasoning clearly. Finally, if a supplier is excluded, the contracting authority is required to notify a Minister of the Crown — and that notification may trigger a PRU investigation and potential debarment proceedings.
The transparency obligations built into the Procurement Act 2023 mean that exclusion decisions carry a paper trail. Authorities must document their reasoning, and that documentation can be scrutinised by the excluded supplier or by the PRU when considering debarment.
Assessment of Contract Performance Notices — What Suppliers Need to Know
Assessment of Contract Performance Notices (ACPNs) are one of the most consequential new mechanisms introduced by the Procurement Act 2023 for suppliers. They apply to public contracts with an estimated value of more than £5 million.
For contracts above this threshold, contracting authorities must set at least three Key Performance Indicators (KPIs) before entering into the contract, and publish those KPIs. At least once every 12 months — and at the point of contract termination — the authority must assess the supplier’s performance against those KPIs and publish the findings in a Contract Performance Notice. Performance is rated from ‘Good’ (meeting or exceeding KPIs) to ‘Inadequate’ (significantly below KPIs).
Where a supplier is not performing to the authority’s satisfaction, has been given a proper opportunity to improve, and has failed to do so, a notice must be published detailing the breach, the steps taken to address it, and why those steps were insufficient. Published notices are visible to all contracting authorities — meaning that a poor performance notice on one contract can make a supplier discretionarily excludable in future procurements by entirely different buyers, provided the circumstances are ongoing or likely to recur.
As a result, for businesses growing their public sector presence and approaching or exceeding the £5 million contract value threshold, understanding ACPN obligations in advance — and having robust KPI management processes in place — is critical.
How the Procurement Act 2023 Changed Supplier Exclusion and Debarment
The Procurement Act 2023 replaced the Public Contracts Regulations 2015 (PCR 2015), which themselves derived from EU procurement directives. The transition represented one of the most significant overhauls of UK procurement law in a generation, coming into force on 24 February 2025. The Act establishes a new procurement regime and introduces a comprehensive exclusion and debarment regime, fundamentally changing how supplier exclusion is managed.
Key changes relevant to supplier exclusion and debarment include the introduction of the centralised Debarment Register — which has no equivalent in the previous PCR 2015 regime. The new debarment regime includes both mandatory and discretionary exclusion grounds, providing contracting authorities with expanded powers to exclude suppliers for a wider range of misconduct. Assessment of Contract Performance Notices are an entirely new transparency mechanism with direct exclusion implications. The Act also expands mandatory grounds to include cartel activity and deliberate tax penalties, and replaces the PCR 2015’s rigid three-test self-cleaning framework with a broader, more flexible assessment approach. Increased transparency obligations mean that investigation reports must be published and exclusion decisions must be documented and notified.
Taken together, these changes mean that supplier compliance is both more formally scrutinised and more publicly visible than under the previous regime. Businesses operating in public sector markets need to understand not just the rules as they were, but how the landscape has fundamentally shifted.
Common Questions About Supplier Exclusion and Debarment
What is a debarment list and how do I check it?
The debarment list is the publicly accessible Debarment Register maintained by the Cabinet Office under the Procurement Act 2023. It lists excluded or excludable suppliers who have been formally barred from participating in in-scope central government contracts. You can check it at GOV.UK by searching for “debarment register.” Businesses should check their own status — and that of key sub contractors, sub contractors, and associated persons — before submitting any public sector tender.
Can a supplier appeal a debarment decision?
Yes. Once notified of a debarment decision, suppliers have an eight-day standstill period during which they can apply to the court for interim relief, such as temporary suspension of the decision. A formal appeal must be commenced within 30 days of knowing of the decision and can only be made on the basis of a material mistake of law. If appealed within the standstill period, the supplier will not be added to the register until the appeal has concluded.
How do I know if my business is at risk of exclusion?
Any of the grounds in Schedule 6 or Schedule 7 of the Procurement Act 2023 could place your business at risk. Common triggers include past criminal convictions, previous poor performance on public contracts where contracts were terminated or damages awarded, involvement in insolvency, misrepresentation in prior procurement processes, and competition law infringements or potential competition infringements. If your business has received an Assessment of Contract Performance Notice on a previous contract, that notice will be visible to future contracting authorities. Breaches of competition law, such as cartel activity or bid-rigging, are also grounds for exclusion.
Do exclusion grounds apply to subcontractors?
Yes — in certain circumstances. The Procurement Act 2023 allows exclusion grounds to extend to associated persons, subsidiary companies, key sub contractors, sub contractors, and connected persons, not just the bidding entity itself. Subcontractors and key supply chain members may therefore need to be assessed against the same exclusion criteria as the prime bidder.
Does supplier exclusion apply to framework agreements?
Yes. Framework agreements are public contracts for the purposes of the Procurement Act 2023, and exclusion rules apply at both the framework agreement entry stage and at the call-off stage when individual contracts are awarded under a framework.
What should I do if I receive an Assessment of Contract Performance Notice?
Respond promptly and constructively. Review the notice carefully, understand which KPIs you are rated against, and engage with the contracting authority to discuss the findings. Where there are grounds to challenge the rating, use the available response process. Where the rating reflects genuine underperformance, begin documenting the steps you are taking to improve — as those steps will be relevant to any future self-cleaning assessment.
For further information and resources on supplier exclusion, debarment, and compliance with competition law, please refer to official guidance and regulatory documents.
Staying Compliant and Competitive as a UK Public Sector Supplier
Understanding supplier exclusion and debarment rules is not just a matter of avoiding the worst-case outcome. It is a practical business discipline that directly affects your ability to bid, win, and retain public sector contracts over the long term. Exclusion and debarment mechanisms can also incentivise suppliers to improve compliance and performance, fostering a more reliable supply chain.
In practice, staying compliant means maintaining clean records on all relevant exclusion grounds, monitoring your supply chain for risk, responding promptly and constructively to any Assessment of Contract Performance Notices, and having clear internal processes for identifying and addressing potential exclusion triggers before they escalate. To reduce bid rigging risk and address particular risks such as cartel activity or competition infringements, it is important to share compliance materials and provide compliance advice to staff throughout your organisation. Sharing compliance materials helps promote awareness and adherence to competition law, supporting your efforts to avoid exclusion or debarment. Businesses that approach compliance proactively — rather than reactively — are better placed to defend their eligibility and, where needed, to demonstrate self-cleaning to the satisfaction of a contracting authority.
Managing public sector procurement activity efficiently, keeping track of your bid history and compliance obligations, and staying informed of regulatory changes takes discipline and the right tools. Delta eSourcing is designed to help UK businesses manage their public sector tender pipeline — from opportunity discovery through to submission — in one organised, accessible place, with integrated tender and procurement management software, end‑to‑end eProcurement software solutions and specialist eSourcing modules for public sector organisations available through a comprehensive procurement, contract and tender management platform. Suppliers can use Delta Supplier Solutions to respond to public sector contracts and opportunities, backed by an easy‑to‑use eTendering platform and support from BiP Solutions and relationships with key public sector procurement partners and frameworks. To build internal capability around the Procurement Act 2023, procurement teams can access Delta’s procurement events and skills conferences, attend webinars on eProcurement and the Delta platform, and deepen their understanding of how eProcurement systems work in practice. Ready to streamline your public sector tendering? Explore the platform at delta-esourcing.com.