PPN 006 / PPN 06/21 compliance: the mistakes that fail UK bids

PPN 06/21 is the Procurement Policy Note the Cabinet Office published in June 2021. People call it PPN 006 too. It means any supplier bidding on an in-scope UK central government contract worth more than £5 million a year has to hold a compliant Carbon Reduction Plan. Buyers assess it as pass or fail at selection, not as a scored criterion.

That is what makes the errors on this page so expensive. A weak Carbon Reduction Plan does not lose you a few marks. Under Cabinet Office guidance it can remove your bid from the process entirely, before an evaluator opens your technical or commercial response. There is no partial credit, and buyers cannot waive the requirement for contracts that meet the threshold.

The £5 million figure is the legal floor, not the practical ceiling. NHS trusts, local authorities, housing associations, universities and framework operators increasingly ask for a Carbon Reduction Plan well below that value. This guide sets out the specific mistakes that cause plans to fail, gives you a pre-flight checklist with clear pass/fail cues, and shows you how to test your plan before the deadline. For a plain-language explainer of the policy itself, see what is PPN 006.

The top 7 fatal mistakes

Each of these is a common reason a Carbon Reduction Plan is rejected at the selection stage of a UK public sector tender. Any one of them can be enough on its own.

1. 1
   Unsigned or stale director sign-off. The plan must be signed by a named director or equivalent, with job title and date. An unsigned plan, or one signed by someone who is not a director, is non-compliant. A sign-off dated more than 12 months before submission is routinely challenged. Some buyers state outright that the plan must have been updated within the previous year.
2. 2
   Missing mandatory Scope 3 subsets. The Cabinet Office technical standard requires specific Scope 3 categories, not a vague acknowledgement. At minimum your plan must quantify business travel, employee commuting, operational waste, and upstream and downstream transportation and distribution. Omitting any of these is a template failure. So is writing "Scope 3 quantification is in progress" with no figures.
3. 3
   Outdated or non-DESNZ carbon factors. All calculations must use the UK Government DESNZ greenhouse gas conversion factors for the reporting year. Factors from a prior year, or from a non-UK source, are a methodology error any evaluator can spot against the published tables.
4. 4
   No baseline comparison or missing trajectory milestones. Stating current-year emissions with no named baseline year, no baseline figure, and no interim milestones on the path to net zero by 2050 leaves an evaluator nothing to measure progress against. A 2050 commitment in isolation, with nothing between now and then, does not read as a credible plan.
5. 5
   Offsets without gross emissions reductions. Carbon offsetting cannot substitute for reducing your own emissions. A plan that leans on offset purchases to claim progress, without evidencing gross reductions from specific measures, will be treated as greenwashing rather than a reduction plan.
6. 6
   No public URL on the supplier website. The plan must be published and publicly accessible on your own website before the tender deadline. A plan that exists only as a tender attachment, sits behind a login, or returns a 404 when the buyer checks the link is treated as unpublished.
7. 7
   Generic, non-standard PDF statements. A sustainability vision statement, an ISO 14001 certificate, or a one-page "our commitment to the planet" PDF is not a Carbon Reduction Plan. The document has to follow the Cabinet Office technical standard structure (baseline, current year, net zero commitment, reduction measures, declaration) or it fails on its face.

Pre-flight checklist

Run every line against your published plan the week before you submit. If any item lands on the fail cue, fix it before the deadline, not after.

Check your plan against the standard before submitting

The checklist above is quicker to run with a second pair of eyes. The free PPN 006 compliance check takes about 60 seconds, tests your plan against the procurement standard, and returns a clear pass/fail result with the gaps flagged, so you catch the disqualifying errors while there is still time to fix them.

How this guide differs from “what is PPN 006”

Still getting your bearings on the policy? Who it applies to, the £5 million threshold, the six mandatory elements of a Carbon Reduction Plan, the annual update requirement. Start with our explainer: What is PPN 006? Procurement Policy Note 06/21 explained. That page tells you what the rules are.

This page is the other half: what goes wrong in practice, and how to catch it. Use it once you already have a draft plan and need to pressure-test it before a deadline. The two are designed to be read together.

For the questions carbon and net zero attract inside the tender response itself, like social value sections and SQ and ITT environmental questions, see the Net Zero tender questions guide. For a full worked walkthrough of building the plan from a blank page, see how to write a Carbon Reduction Plan (PPN 006 guide).

Frequently asked questions