Collecting ESG data from sites and suppliers without losing the trail

Most ESG reporting problems are collection problems in disguise. A figure that arrives in March, in the wrong unit, from someone who has since left, with no bill attached, is hard to approve and harder to assure. This guide covers how to design collection from your own sites and from suppliers so that each figure arrives ready to approve.

Decide the design before the first figure arrives

For every indicator you report, settle six things and write them down:

This takes a few days once and can save much more every year. It is also among the first things an assessor or assurer asks for: your methodology, your boundary³ and who is responsible for what.

Habits that keep site data approvable

• Collect monthly. Small, regular entries are easier to check than a year reconstructed in March, and gaps show up while they can still be filled.
• Capture evidence at entry. A photo of the meter, the bill, the register page — attached when the figure is entered.
• Reconcile, don't just record. Fuel consumed should agree with purchases and stock; electricity with the bills; headcount with payroll.
• Explain big movements when they happen. A reason written by the person who knows ("boiler shut for 12 days in August") is worth more than one guessed later.
• Mark what does not apply. A site without a DG set should say "not used at this site", with the reason, rather than leave a blank that looks like missing data.
• Agree an estimation rule in advance. When a bill is late, how is the month estimated, by whom, and how is it corrected when the bill arrives?

Where data already lives in a system — the ERP for purchases and spend, the HR system for headcount, meters with data loggers — import it, but keep a reference to the source record so the figure can be traced.

Which suppliers should you ask?

You cannot ask everyone, and you should not try. Two lenses help:

• BRSR's value chain rule. SEBI's revised value chain disclosure covers partners that are individually 2% or more of purchases or sales by value, and lets a company stop at partners covering 75%, stating the coverage it reached. It is voluntary for the top 250 from FY 2025-26¹.
• Scope 3 hotspots. Rank purchases by spend and by likely emissions intensity. A few raw-material suppliers usually outweigh hundreds of service providers.

What should you ask them for?

Ask for little, and ask for things the supplier can answer:

1. Their Scope 1 and Scope 2 emissions for a stated period, with the method and whether they were verified;
2. Their total revenue for the same period (to allocate their emissions to you);
3. Where relevant, product-level figures — emissions per tonne of the material you buy — which are more precise than an allocation;
4. For BRSR value chain disclosures, the specific indicators you will report on their behalf.

Make answering easy: one short form, a private link rather than a login, the period and units fixed in advance, and their previous answer pre-filled next year. A supplier who answers several customers will appreciate being able to reuse one profile.

How do you allocate a supplier's emissions to you?

The GHG Protocol's Scope 3 Standard prefers supplier-specific data where you can get it². When a supplier gives you its total emissions rather than product figures, a common approach is to allocate by your share of its revenue:

State the method, because allocation by revenue assumes your purchases are as emissions-intensive as the supplier's average product. This covers the supplier's own Scope 1 and 2 only: category 1 is meant to be cradle-to-gate, so add an estimate of the supplier's upstream emissions (its own Scope 3, or a secondary factor for its main inputs) or state that they are excluded. When the supplier can give a product-level, cradle-to-gate figure — tonnes of CO₂e per tonne of steel — use that with the tonnes you bought instead.

Score the quality of what you receive

Not every answer is equally good. Record, for each supplier figure:

Reporting the share of Scope 3 that rests on supplier-specific data — and raising it year by year — is more credible than a precise-looking total built mostly on averages.

Common mistakes

• Mixing periods. Indian companies report on an April–March financial year; suppliers abroad and some multinational groups use a calendar year. Use the closest period available and say which.
• Counting twice. Freight you pay a transporter for (category 4) can be counted again if it is also inside a supplier's price you estimate under category 1.
• Chasing everyone. Hundreds of small requests with low response rates produce little; a few well-chosen partners usually matter more.
• Losing the answer. Supplier replies kept in e-mail cannot be traced or reused next year.

How ESGTrack helps

ESGTrack gives each kind of site data its own form — fuel logs reconciled with stock checks, meters and bills, water as a balance, waste by BRSR category — and an offline field app for meter readers, with a photo as evidence and approval before anything is reported. Suppliers answer through a private link, with evidence and reminders, and a supplier network lets one profile serve every customer; allocation and the BRSR value chain disclosure follow from the answers. See supplier and value-chain data and how collection works.