How to answer a supplier sustainability questionnaire without overclaiming

Your largest customer has sent a supplier sustainability questionnaire. The deadline is a few weeks out, and nobody in the building owns the answer. That’s normal for a mid-size Kentucky manufacturer. The fastest way through isn’t better prose. It’s one organized data file, every questionnaire answered from that file, and figures labeled for what they are: non-certified estimates based on published methods.

Here’s the short version. Most questionnaires ask about the same handful of topics. Put your electricity and fuel records in one place, calculate Scope 1 and Scope 2 using the GHG Protocol, decide what you’re willing to commit to before you answer target questions, and never claim renewable energy, verification or targets you can’t document. A careful “not yet” holds up better than a confident claim that falls apart at the first follow-up question.

What a supplier sustainability questionnaire usually asks

Some arrive as a spreadsheet, some through a customer’s supplier portal, and some through platforms such as CDP or EcoVadis. The underlying questions are remarkably similar:

• Energy use. Annual electricity in kWh or MWh, plus natural gas, propane, diesel and gasoline, often broken out by site.
• Emissions. Scope 1 and Scope 2, plus Scope 3 (your value chain) from larger customers.
• Targets. Whether you have an emissions or energy reduction target, with its base year, target year, percentage and the scopes it covers.
• Renewable energy. What share of your electricity is renewable, how you claim it, and what you plan to do next.
• Policies and governance. An environmental policy and who is responsible for it.
• Evidence. Uploaded documents that back up the answers.

Your customer isn’t asking out of curiosity. CDP says its supply chain members use supplier data in their own reporting and Scope 3 accounting, so the number you send may become part of your customer’s published inventory. Treat it like a figure on an invoice.

Question by question: the data behind each answer

This is the map we start from, including where first-time responders most often go wrong.

Typical question	Data you need	Where it usually lives	Common mistake
Total electricity use last year	Every meter’s kWh for 12 months	Utility bills or the utility’s online account	Missing a second meter, such as a warehouse, well pump or sign
Scope 1 emissions	Natural gas, propane, diesel, gasoline and refrigerant top-ups	Gas bills, fuel delivery tickets, fleet cards, HVAC service records	Forgetting forklifts, yard trucks and backup generators
Scope 2, location-based	Electricity by site plus the grid emission factor for each site’s region	Bills plus EPA eGRID subregion factors	Using a national average, or not recording the eGRID edition
Scope 2, market-based	Contracts or certificates for any renewable or supplier-specific electricity	Utility program agreements, certificate retirement records	Claiming renewable electricity because the grid has some
Reduction target	A decision your owners or board actually made	Meeting minutes or a signed policy	Reporting an aspiration as an adopted target
Renewable energy plans	The real status of a project or decision	Feasibility studies, proposals, utility program enrollment	Describing an installer’s quote as a plan
Environmental policy	A dated, signed document	HR or environmental, health and safety files	Uploading a draft, or a policy nobody has reviewed in years
Third-party verification	An assurance statement, if one exists	The verifier’s letter	Checking “verified” because a consultant helped

Build one data file, not ten separate answers

Assemble one data file that every future answer draws from. Ours usually has nine parts:

1. A meter and account list. Every electric and gas account, with its address, utility, rate schedule and what it serves. The forgotten meter is the most common gap we find.
2. Twelve to 36 months of bills. Usage, not just dollars. Costs don’t convert to emissions.
3. Fuel records. Gas bills, propane and diesel tickets, fleet fuel cards and generator logs.
4. Refrigerant service records. The pounds added during service are a common starting point for estimating leaks.
5. A boundary decision. The GHG Protocol Corporate Standard lets a company consolidate emissions by operational control, financial control or equity share. Pick one, write down why, and list which sites are in and which are out. Leased space is where most inconsistencies start.
6. A base year. The first full year you can document well, plus a note on when you’d recalculate it, such as after selling a site.
7. Factor sources and editions. Note which EPA eGRID edition, which fuel emission factors and which global warming potential values you used. When a factor dataset updates, your emissions can change even if your usage didn’t.
8. A calculation workbook and a methods note. One page in plain English explaining how each number was built.
9. An answer log. Which customer asked what, when, what you said and who approved it.

Most companies skip the answer log. It saves the most time next year.

Scope 1 and Scope 2, in brief

Scope 1 covers direct emissions from sources you own or control: the boiler, the ovens, the forklifts, company vehicles and refrigerant leaks. Scope 2 covers indirect emissions from the electricity, steam, heat or cooling you buy. Which one is larger depends mostly on how much natural gas or other fuel your process burns.

The GHG Protocol’s Scope 2 Guidance expects companies to report Scope 2 two ways. A location-based figure uses average grid emission factors for the region where you consume electricity. A market-based figure reflects the contracts and certificates you hold. The GHG Protocol’s own FAQ says dual reporting applies even if you haven’t bought any renewable energy. We explain the two methods, and why they can differ, in Scope 2: location-based vs. market-based. For questionnaire purposes the rule is simple: report both, label both, and say which one you use to track progress.

CDP supply chain requests

CDP runs a global environmental disclosure system. Through its supply chain program, member companies ask their chosen suppliers to disclose through CDP; CDP says more than 45,000 suppliers were requested in 2025. In the CDP portal, requested organizations can see which entities asked them to disclose.

A few things are worth knowing before you start:

• One response, many readers. CDP describes its format as “write once, read many.” Suppliers responding to a customer’s request answer the main questionnaire, plus supply chain questions relevant to that customer. One disclosure can serve several customers.
• A shorter path for smaller companies. CDP offers an SME questionnaire tailored to the resources of smaller organizations, with eligibility tied to revenue and headcount. In 2026, CDP introduced an A score for climate change on the SME questionnaire.
• Fees depend on who asked. CDP’s FAQ says organizations requested only by supply chain members, or by certain other requester types, are exempt from its administrative fee. A request from CDP’s capital markets signatories brings the fee back. Check the FAQ for the cycle you’re in.
• It runs on an annual cycle. In 2026, the disclosure window opened in June and closed in October. Dates are set each year, so check CDP’s published schedule as soon as a request arrives.
• Scoring is staged. CDP scores responses across four levels: disclosure, awareness, management and leadership. An accurate first-year response that is candid about gaps is a reasonable start.

EcoVadis-style assessments

Some customers use a ratings platform instead of CDP, or alongside it. EcoVadis is a widely used example. Its scorecards cover four themes: environment, labor and human rights, ethics, and sustainable procurement. Its methodology weighs the issues material to your industry, the countries you operate in, and the size of your company. The burden of proof sits with you. EcoVadis says rated companies must provide supporting documents, such as policies, certificates and metric reports, which a team of sustainability experts reviews.

The lesson carries across any evidence-based assessment: a policy you can’t upload may earn little or no credit. Gather dated, signed copies of your policies and the records from your data file first. If a policy doesn’t exist yet, write a real one that reflects what you actually do, not a downloaded template nobody follows.

We aren’t affiliated with EcoVadis or CDP. We help suppliers organize the data and documents these platforms ask for. The response, and the score, belong to you.

Keep every answer consistent

Customers compare, and some see your answers in more than one place. These are the inconsistencies we see most often:

• Different periods. One questionnaire asks for calendar 2025, and another asks for your fiscal year. Label which one you used, every time.
• Different units. kWh in one place and MWh in another, or short tons instead of the metric tons of CO2e that GHG Protocol-based questionnaires expect.
• Different boundaries. The main plant in one response and all three sites in the next.
• Different factors. A new eGRID edition in one response but not another sent the same month.
• Silent restatements. If you correct last year’s number, say so and explain why.

What not to overclaim

Most of the risk in a questionnaire comes from claims, not arithmetic.

• Don’t call your figures verified unless they are. You need an assurance statement from an independent verifier. Estimates prepared by your team or by a consultant, including us, are non-certified estimates.
• Don’t claim “100% renewable” or “carbon neutral” without the paperwork. A renewable claim needs contractual instruments and retirement records. A neutrality claim also needs the offsets and a stated methodology. Even rooftop solar you own supports a renewable claim only if you keep its environmental attributes and haven’t sold the certificates.
• Don’t report a target your owners haven’t adopted. “We aim to reduce emissions” isn’t a target with a base year and a deadline.
• Don’t describe a proposal as a plan. Say what stage you’re at: evaluating, approved, contracted or operating.
• Don’t drop a site because its data is messy. Estimate it, and explain how.
• Don’t answer legal questions on the fly. If a customer cites a regulation, ask which one and confirm your obligations with your attorney. We don’t give legal advice, and this post covers voluntary customer requests, not mandatory disclosure laws.

How long it takes

For a first questionnaire, the bottleneck is usually collecting usage data, not calculating emissions. A realistic sequence for a mid-size supplier with several meters:

Step	Rough time for a first-year responder
Pull 12–36 months of electricity and gas usage for every account	1–2 weeks, longer if online account access has to be set up
Collect fuel tickets, fleet cards and refrigerant service records	1–2 weeks, often in parallel
Decide the boundary and base year, and get owner sign-off	A meeting or two
Calculate Scope 1 and both Scope 2 figures, and write the methods note	A few days once data is complete
Draft answers, gather evidence documents and review internally	About a week

When we do this work, a Supplier Sustainability Questionnaires engagement typically takes 2–4 weeks from complete documents. A first full inventory through Carbon & Scope 2 Reporting usually takes 3–6 weeks in year one and less after that. If your customer’s deadline is sooner, tell them early. A request for more time with a clear plan usually lands better than a missed date. The second year is faster, because the data file, the boundary and the answer log already exist.

As of November 1, 2026

• CDP. The 2026 disclosure cycle ran from June to October, and CDP’s 2026 page says the response window has closed. Check CDP’s site for 2027 dates.
• GHG Protocol. The GHG Protocol is revising its Scope 2 Guidance. A public consultation ran from October 20, 2025, to January 31, 2026. Its October 2026 status update says a consolidated public consultation is slated for Q2 2027 and a joint GHG Protocol–ISO standard for Q4 2028, and several requirements are still undecided. Until a revision is published and takes effect, the 2015 guidance, including dual reporting, is the reference.
• Emission factors. Datasets such as EPA eGRID are updated periodically, so record the edition you use.

What we’d do

If a questionnaire landed on your desk this week, we’d:

1. Read every question once and sort them into “have the data,” “can estimate” and “not yet.”
2. Ask the customer which reporting period and units they expect, and whether CDP or another platform is involved.
3. Build the data file before writing a single answer.
4. Calculate Scope 1 and both Scope 2 figures, label them as non-certified estimates, and write a one-page methods note.
5. Decide with the owners what you’re willing to commit to on targets and renewable energy, and answer those questions only after that conversation.
6. Keep an answer log, so the next customer gets the same numbers.

To see how this plays out for a hypothetical parts supplier, read our illustrative Scott County questionnaire scenario. If renewable energy questions are where you get stuck, green tariff vs. RECs vs. on-site solar compares what each option lets you claim.