Getting a Sustainability Questionnaire When You Have No Emissions Data

The Most Common Position for a First-Time Reporter

You receive a sustainability questionnaire from a client. You open it. It asks for your Scope 1, 2, and 3 emissions in tCO2e. You have no idea what those numbers are. You have never measured anything. The bills are somewhere, but you have not looked at them for carbon purposes.

This is where most SMEs are on day one. It is completely normal, and it is completely solvable.

What "I Don't Have the Data" Usually Means in Practice

When suppliers say they do not have their emissions data, it almost always means one of three things:

1. They have the data but have not converted it — gas bills, electricity bills, and fuel records exist, but no one has applied emission factors to them. This is the most common situation.
2. Some data is missing — for example, fuel use is tracked but gas consumption is not separately metered. This is solvable with reasonable estimates.
3. The business truly has minimal data — a sole trader or micro-business with no gas, no vehicles, and low electricity use. In this case, the actual emissions are very small and easy to estimate.

None of these situations prevent you from producing a credible response.

Step 1: Retrieve What You Do Have

Spend 20 minutes gathering:

• Any gas bill from the last 12 months (look for kWh or m³ — your supplier can send a full-year summary by email)
• Any electricity bill (annual kWh — your supplier or a smart meter app will have this)
• Fuel card statements or expense claims mentioning diesel or petrol volumes
• Your current headcount (the number of people on the payroll)

If you cannot get exact figures in time, move to estimates.

Step 2: Use Reasonable Estimates (They Are Accepted)

The GHG Protocol Corporate Standard explicitly allows the use of reasonable estimates where precise metered data is unavailable. Procurement questionnaires accept estimates — the key requirement is that you state your methodology clearly.

How to estimate gas use: UK offices typically use 100–200 kWh of gas per m² per year. Multiply your floor area by 150 kWh/m², then convert: kWh ÷ 11.2 = approximate m³, then m³ × 2.04 kgCO2e ÷ 1,000 = tCO2e.

How to estimate electricity use: UK SME offices typically use 50–100 kWh per m² per year. Multiply floor area by 75 kWh/m² as a starting estimate.

How to estimate commuting: Employees × average commute km (round trip) × 220 working days × 0.170 kgCO2e/km (car) × 0.6 (typical car share) ÷ 1,000 = tCO2e.

Step 3: State Your Methodology Clearly

When you submit estimated figures, add a note:

> "Scope 1 and 2 figures are based on estimated consumption derived from floor area and sector benchmarks, pending retrieval of metered utility data. Scope 3 figures are estimated using DEFRA 2023 commuting and travel factors. All figures will be updated to actuals in the next reporting cycle. Methodology: GHG Protocol Corporate Standard."

This statement is honest, professional, and completely acceptable to enterprise procurement teams for a first-time submission.

Step 4: Use a Tool to Do the Calculations

The estimation calculations are not complex, but they are easy to get wrong when you are doing them manually under deadline pressure. DeCarbonOPS lets you enter estimated figures alongside actuals — there is no requirement to use only metered data. Enter your best estimates, get your tCO2e outputs, generate a Carbon Passport with a verification URL, and submit.

What to Do About Missing Data After Submission

Once you have submitted your estimated response, take 30 minutes to set up data collection for next year:

• Ask your gas supplier for an annual summary report (most will send this automatically if you request it)
• Enable smart meter monitoring for electricity
• Set up a simple spreadsheet to log monthly fuel card totals
• Ask your waste contractor to include annual tonnage totals in their invoices

With these four actions, your next annual report will be based on actual data throughout — and will take even less time to complete than your first.