Sustainability in tenders used to mean a tick-box question near the end of the form. Not anymore. Since the Procurement Act 2023 came into force in February 2025, sustainability has moved from a nice-to-have into a formal evaluation standard and, on larger contracts, a mandatory KPI. Buyers aren’t checking whether you have a policy. They’re checking whether you can prove it, measure it, and deliver it. 

Why this matters 

• Revenue. In central government procurement, social value – which folds in environmental outcomes – carries a minimum 10% weighting under PPN 002, and some contracting authorities already go higher. On a closely matched bid, that’s often the deciding factor. 

• Risk. A weak sustainability answer can knock a supplier off the shortlist even when the price is competitive. 

• Relationships. A credible track record makes the next renewal easier to win, not just the current bid. 

The questions buyers are asking 

1. Can you prove it, not just claim it? A one-page environmental policy no longer passes. Evaluators want data with carbon figures, supplier audits, measurable outcomes from past contracts, and they want it recent. A claim from three years ago reads as stale even if it was accurate at the time; buyers increasingly expect verified figures from the last 12 months. This isn’t limited to central government either – Brighton & Hove City Council, for example, builds sustainability questions directly into its supplier pre-qualification stage, with its own guide on how to answer them. 

2. Does this relate to the contract you’re bidding for? Generic sustainability statements score badly. A cleaning contractor talking about biodiversity net gain on a site they’ll never touch won’t score well; one explaining how their product choices and delivery routes cut impact on this contract will. Specificity beats breadth every time. 

3. What’s your social value contribution, not just your environmental one? Under the Most Advantageous Tender approach that replaced the old Most Economically Advantageous Tender model, buyers now weigh social value, local employment, skills, SME and community benefit right alongside carbon and environmental criteria. A supplier who can only speak to environmental performance is answering half the question. 

4. What KPIs will you be measured against? Contracts above £5 million must publish at least three Key Performance Indicators, and sustainability is commonly one of them. Vague ambitions don’t translate into a KPI – specific, trackable commitments do. If a contract manager couldn’t monitor it quarterly, it won’t score well. 

5. How will you engage your own supply chain? Most organisations’ environmental impact sits upstream rather than in their own operations – supply chain emissions typically run many times higher than a company’s direct footprint (read more about this in our blog). Buyers now expect a plan for bringing subcontractors and suppliers along, not just a tidy account of the bidder’s own site. 

6. Do you have a Carbon Reduction Plan? For central government contracts above £5 million a year, PPN 006 makes this a mandatory precondition of bidding, not just supporting evidence – separate from, and often checked before the social value scoring under PPN 002. It needs to cover the required emissions scopes, carry senior sign-off, and be published on your website, so it’s often the first document a buyer looks for. 

7. Can your claims survive scrutiny? Buyers must now justify their award decisions more rigorously than before, and that pressure passes down to suppliers. Expect deeper questions on ethical sourcing, exclusion grounds, and third-party verification. Accreditations and independently verified data do the work of proving a claim, so the evaluator doesn’t have to take your word for it. 

8. Does your bid match what’s public about you? Buyers cross-reference a tender response against your website, case studies, and published reports. A bold claim in a bid document without supporting evidence elsewhere is a red flag, not a minor issue. 

Tender-ready checklist 

• Verified sustainability data that’s under 12 months old 
• A sustainability commitment specific to the contract, not a generic statement 
• A clear social value position, not just an environmental one 
• KPIs a contract manager could genuinely track quarterly 
• A stated plan for engaging your own supply chain 
• Accreditations or third-party verification to back your claims 
• Public-facing content that matches what the bid says 

The takeaway 

Sustainability in tenders has moved from a compliance exercise to a genuine point of competitive differentiation. Buyers are looking for suppliers who can show, with evidence, that sustainability is built into how they operate, not bolted onto how they bid. 

For businesses that haven’t yet built this evidence base, the work starts well before the next tender lands. Carbon Reduction Plans, measurable social value commitments, and a consistent public record all take time to build – but they’re exactly what separates a response that scores well from one that reads well. 

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