Best Carbon Reduction Plan Software for PPN 006 Compliance: 2026 Guide

Quick Answer: The best carbon reduction plan software for PPN 006 compliance measures your full Scope 1, 2, and 3 emissions, produces a GHG Protocol-aligned output with senior sign-off, and tracks reduction progress year-on-year. Seedling is built specifically for this use case. Plan A and Greenly are strong alternatives for larger organisations with more complex reporting needs.

If you bid for UK public sector contracts, you already know the pressure. PPN 006 (formerly PPN 06/21) requires suppliers above a certain threshold to submit a Carbon Reduction Plan with every tender, and the requirements are specific: GHG Protocol-aligned data, Scope 1, 2, and relevant Scope 3 emissions, a net zero commitment, and senior leadership sign-off. Spreadsheets make that hard to maintain year-on-year. The right carbon reduction plan software makes it manageable. This guide covers the best options available in 2026, with an honest assessment of who each tool is right for.

What Does a Compliant Carbon Reduction Plan Actually Require?

A compliant Carbon Reduction Plan for PPN 006 needs five elements: a commitment to net zero by 2050, a baseline emissions figure and current-year data following GHG Protocol standards, coverage of Scope 1, 2, and selected Scope 3 categories, an action plan showing how reductions will be achieved, and senior leadership sign-off.

That means the software you choose needs to do more than calculate a number. It needs to produce an output your procurement team can submit with confidence, that your carbon data is accurate and auditable, and that you can update it each year without starting from scratch.

Seedling's Carbon Reduction Plan guidance covers the specific requirements in detail if you want to check your current approach against the standard.

The 6 Best Carbon Reduction Plan Software Tools: Our Top Picks

1. Seedling: Best for SMEs Needing PPN 006-Ready Outputs

What it does well: Seedling combines carbon management software with a dedicated carbon expert who guides you through the full measurement and reporting process. The platform covers Scope 1, 2, and 3 emissions aligned with the GHG Protocol, and produces compliance-ready outputs, including Carbon Reduction Plans formatted for PPN 006 submissions. The process typically takes 2-4 weeks end-to-end, with less than one day of your time overall, but Seedling can expedite to complete Carbon Reduction Plans within a day.

Accounting integrations with Xero, Sage, and QuickBooks reduce manual data entry, and built-in employee and supplier surveys capture harder-to-reach emissions categories. Your dedicated account manager also builds a bespoke, quantified decarbonisation plan, so the reduction action plan required by PPN 006 is grounded in your actual data rather than generic recommendations.

Best for: Companies of up to roughly 2,000 employees that need a credible, auditable Carbon Reduction Plan without a full-time sustainability team to maintain it. Particularly well-suited to Ops Leads, HSE Managers, and Compliance Managers managing carbon alongside other responsibilities.

Seedling is also a strong fit if you need outputs beyond PPN 006, including B Corp Climate Action, SECR, EcoVadis, and ISO 14064 verification.

Pricing: Subscription pricing. See Seedling's pricing page for current plans.

2. Plan A: Best for Mid-to-Large Companies with CSRD Alongside PPN 006

What it does well: Plan A is a carbon management platform built for organisations that need to meet multiple regulatory requirements at once. The platform is TÜV-certified and SOC 2 compliant, and uses AI to guide data mapping, detect anomalies, and connect emissions data to reduction action plans. It supports decarbonisation scenario modelling and can project the return on investment of different reduction pathways. Plan A is trusted by large organisations including BMW, Visa, and Alphabet, which reflects its strength in the mid-to-large company segment.

Best for: Companies that need to manage PPN 006 as part of a broader compliance picture that includes CSRD, and that have in-house sustainability resource to get the most from the platform's depth.

Where Seedling differs: Seedling is built for companies that want high-quality carbon data and compliance-ready outputs without the enterprise-level onboarding workload. If your primary goal is PPN 006 compliance with a lean team, Seedling's guided process and dedicated expert support get you there faster. See Plan A alternatives for a fuller comparison.

3. Greenly: Best for Companies Wanting Sector-Specific Guidance

What it does well: Greenly is a carbon accounting platform based in France that serves companies of various sizes. It integrates data analysis with sector-specific climate expertise, and pairs platform users with consultants who can provide custom guidance. The platform is designed to reduce the effort required for a carbon assessment, with rapid data import capabilities and emissions calculation algorithms. Greenly builds customised carbon emission reduction plans based on a company's specific emission hotspots, and its supplier engagement tools help track Scope 3 across the value chain.

Best for: Companies that want a data-driven reduction plan shaped by sector expertise, and that have the internal capacity to work with a platform that covers a broad range of use cases.

Where Seedling differs: Seedling is purpose-built for the UK compliance market, with outputs formatted specifically for PPN 006, SECR, and related frameworks. If UK public sector tendering is your primary driver, Seedling's compliance-ready outputs and dedicated account management are a more direct fit. Compare options on the Greenly alternatives page.

4. SME Climate Hub – simple starter tool

What it does well: The SME Climate Hub offers a very simple free carbon footprint calculator alongside its climate commitment resources. The tool is designed to give SMEs a quick estimate of their impact and to encourage public Net Zero commitments. You enter a small set of numbers – typically energy use, staff numbers, and a few activity metrics – and the tool returns an estimated result. It uses standard factors, but the methodology is intentionally streamlined.

Best for: Businesses that are very small, simple and just starting out that are happy to use the data from the tool and fill in their own Carbon Reduction Plan, as the tool itself does not provide PPN 006-ready outputs.

Where Seedling differs: Seedling's PPN 006 makes it easy to automatically produce reports in the required format - no manual copy and pasting or reporting formatting needed.

5. CarbonFootprint.com – Carbon Footprint Calculator

What it does well: CarbonFootprint.com offers a well-known online calculator "Sustrax" alongside a consultancy service. Their tools allow you to enter fuel, energy, and travel data and receive a fairly detailed result. The calculator is easy enough to use for basic categories, and the site offers additional tools for specific activities. For more nuanced Scope 3 categories or complex organisations, you are typically directed toward their paid consultancy.

Best for: Businesses that are happy to fully self-serve on a tool without consultant support - or happy to pay more expensive day rates for that support. Like the SME Climate Hub, the tool also does not have PPN 006-ready outputs, so businesses either need to create those themselves or request consultant support at higher rates.

Where Seedling differs: Seedling's process includes both software and expert support as standard. When your data is in and footprint is calculated, your expert puts your Carbon Reduction Plan together right away for you to check, sign and add to your website.

6. Normative: Best for Businesses with Scope 3 Visibility Gaps

What it does well: Normative offers a carbon accounting and carbon network platform that provides enhanced visibility into Scope 3 emissions, which are notoriously difficult to track accurately. The platform supports collaboration across supply chains and provides a free carbon calculator for smaller suppliers, which makes it easier to gather emissions data from suppliers who may not have their own carbon accounting tools. Normative underpins the SME Climate Hub Business Carbon Calculator.

Best for: Businesses where Scope 3 supply chain emissions are the biggest measurement challenge, and where engaging smaller suppliers in data collection is a priority.

Where Seedling differs: Seedling includes built-in supplier surveys to capture Scope 3 data as part of the standard measurement process, alongside a dedicated carbon expert who helps interpret and act on the results. For companies that need both the data and the compliance output, Seedling covers both in a single workflow.

How We Chose These Tools

Every tool on this list was evaluated against the requirements of a compliant Carbon Reduction Plan: full Scope 1, 2, and 3 coverage aligned with the GHG Protocol, the ability to produce audit-ready outputs, and ongoing support for annual updates. We also considered the realistic resource requirements for a lean team, the clarity of the reduction planning output, and whether pricing is transparent or requires a custom quote.

Tools primarily aimed at enterprise ESG reporting or real-time monitoring are not included, as they serve a different use case to the one most PPN 006 suppliers actually face.

FAQs

Q: How much does a carbon reduction plan cost?

A: Costs vary by provider and delivery model. Consultant-led Carbon Reduction Plans typically start from around £1,000 for basic packages, with day-rate models scaling upward depending on complexity. Software-led approaches like Seedling use subscription pricing, which covers annual measurement, expert support, and compliance-ready outputs without variable day-rate costs.

Q: How do you make a carbon reduction plan?

A: A compliant Carbon Reduction Plan requires five elements: a net zero by 2050 commitment, a GHG Protocol-aligned baseline and current-year emissions figure covering Scope 1, 2, and selected Scope 3 categories, a concrete action plan for achieving reductions, and senior leadership sign-off. Carbon reduction plan software automates the measurement and output steps so the plan is based on real data rather than estimates.

Q: What software is used for carbon reporting?

A: Carbon reporting software ranges from enterprise platforms like Plan A, Sweep, and Watershed to purpose-built tools like Seedling that are designed for SMEs and compliance-focused reporting. The right choice depends on your company size, reporting requirements, and internal resource. For PPN 006 specifically, you need a tool that produces a GHG Protocol-aligned output with the required document structure.

Q: Is Seedling right for PPN 006 compliance?

A: Yes. Seedling is built to produce the exact outputs required by PPN 006: a GHG Protocol-aligned carbon footprint covering Scope 1, 2, and 3, a quantified decarbonisation plan, and a formatted Carbon Reduction Plan ready for tender submission. The process typically takes 2-4 weeks end-to-end, with a dedicated carbon expert guiding you through each step. See Seedling's PPN 006 Carbon Reduction Plan solution page for full details.

Q: Can carbon reduction plan software handle the annual update requirement?

A: Good carbon reduction plan software should make the annual update straightforward, not a repeat of the full initial process. Seedling's model includes an annual refresh that keeps reporting consistent year-on-year, improves data quality over time, and tracks progress against your reduction targets, so each year's submission builds on the last rather than starting from scratch.

About Seedling

Seedling is carbon management software built for businesses that want a high-quality, GHG Protocol-aligned carbon footprint without the workload of enterprise software or the cost of a consultant-led project. Trusted by 500+ businesses, Seedling pairs intuitive software with a dedicated carbon expert who guides you through measurement, reduction planning, and compliance-ready reporting, including PPN 006, SECR, B Corp, EcoVadis, and ISO 14064. Setup takes 2-4 weeks, and the entire process typically requires less than one day of your time. Book a demo or explore the platform to see how it works.