For most organisations, Scope 3 (the emissions in your supply chain) is the elephant in the room. It often makes up 80% or more of a company's footprint, yet it's the hardest to measure because the data sits with dozens or hundreds of suppliers. Here's how to do it better.
Updated 7 Oct 2026: the CSRD reference reflects the Omnibus I changes, and the sections on automation and AI extraction describe what Zoru does today.
Why Scope 3 can't be ignored
The GHG Protocol defines 15 categories of Scope 3 emissions, from purchased goods and services to business travel and end-of-life treatment of products. The largest companies in scope of the CSRD, and companies setting science-based targets, are increasingly expected to report Scope 3.
There's a strategic argument too. If most of your footprint sits in the supply chain, any credible net-zero strategy has to address it. Investors, customers and regulators now ask not just whether you report Scope 3, but how robust your method is.
You can't manage what you can't measure. And you can't measure Scope 3 without your suppliers' help.
The common challenges
Anyone who has tried Scope 3 data collection at scale will recognise these:
- Low response rates. Suppliers are busy and may lack the expertise, systems or incentive to reply to your questionnaire.
- Inconsistent formats. One sends a PDF report, another a spreadsheet, a third a rough estimate by email.
- Uncertain quality. Suppliers may mix up Scope 1 and 2, use outdated factors or simply guess.
- Coverage gaps. Categories like capital goods are hard to get primary data for, so spend-based estimates fill the gap.
- Annual repetition. Without a system, the whole process starts again next year and teams burn out.
A smarter approach to supplier engagement
The most successful Scope 3 programmes treat supplier engagement as a relationship, not a transaction. Here's the framework that works.
Tier your suppliers by impact
Use spend data or sector-level factors to estimate which suppliers contribute most to your footprint. Focus primary data collection on the top 20% by estimated emissions, and use industry averages for the long tail.
Make it easy to respond
Complexity is the biggest barrier. Skip the 50-page questionnaire and ask for the minimum you need. Pre-fill fields where you can and offer more than one way to submit.
Explain the why
Suppliers engage when they understand why you need the data and how it helps them. Frame it as a partnership, and share benchmarks back to them.
Set deadlines, with gentle reminders
A single email disappears. Build a cadence: the request, a follow-up at two weeks, a reminder at four, then a final escalation.
The role of automation
Manual outreach stops scaling somewhere around a few dozen suppliers. Whatever tool you use, automation can take over the repetitive parts: sending requests, tracking who has replied, chasing the rest and pulling every response into one place.
Zoru doesn't send or chase supplier requests, so asking suppliers happens outside Zoru. What Zoru does is the groundwork: it builds your supplier register from your purchase ledger, ranks suppliers by what you spent and shows the estimate your purchased-goods entries already hold for each one, so you know whom to ask first. You can add asking your biggest suppliers to your action plan, with an owner.
Using AI to extract data
A lot of the data behind Scope 3 arrives as documents: fuel invoices, travel bookings, utility bills and spreadsheet exports from finance. AI reading can pull the figures out of those so nobody has to re-key them. In Zoru that works for your own bills, invoices, receipts and spreadsheets.
Treat extracted data as a draft. Check the reporting period, the units and whether electricity figures are location-based or market-based before you accept them.
Building a multi-year programme
Year one is about coverage: get your biggest suppliers reporting and use spend-based estimates for the rest. From year two, the goal shifts to quality, moving more of your footprint from estimates to supplier-specific data.
- Keep everything in one place. Contacts, past responses and evidence, so next year starts from last year's data rather than a blank sheet.
- Track data quality. Record whether each figure is supplier-specific, average-data or spend-based, and show the mix improving over time.
- Close the loop. Share results back with suppliers and bring your biggest emitters into your reduction plan.
Start small. Pick your top 20 suppliers by estimated emissions, send a short request and build the cadence. The data won't be perfect in year one, and it doesn't need to be. What matters is a method you can repeat and improve.