Business Carbon Footprint: The Data You Need by Scope
A business carbon footprint is the total greenhouse gas emissions caused by a company's activities, grouped into Scope 1, 2 and 3. To calculate it you need activity data for each scope (fuel, electricity, purchases, travel, freight and waste), a matching emission factor for each item, and a clear record of the gaps you estimated. This article is a data checklist, not a calculation walkthrough. For the full method, from setting boundaries to reporting, see our step-by-step guide to calculating your business carbon footprint. Here we focus on the part that usually takes longest: finding the numbers. What data do you need for a business carbon footprint? Every line in a footprint follows one formula: activity data × emission factor = emissions. Activity data is a measured quantity, such as kilowatt-hours of electricity, litres of diesel or kilometres flown. An emission factor converts it into carbon dioxide equivalent (CO2e), a unit that expresses all greenhouse gases in terms of the warming effect of CO2. Public factor sets such as the UK Government's greenhouse gas conversion factors and the US EPA's Emission Factors Hub are widely used; note which edition you applied. The GHG Protocol Corporate Standard defines the three scopes. Scope 1 is direct emissions from sources you own or control. Scope 2 is purchased electricity, heat, steam and cooling. Scope 3 is all other indirect emissions in your value chain, upstream and downstream. Before collecting anything, set your organisational boundary (many smaller companies use operational control, covering the sites and vehicles they run) and a reporting year, ideally your financial year. Scope 1 and Scope 2: the data checklist This data usually sits with finance, facilities and fleet teams. Collect it by site and by month, so missing periods stand out. Gas and heating fuels (Scope 1): supplier invoices or meter readings. Replace estimated readings with actual ones. Company vehicles (Scope 1): fuel-card reports in litres; mileage logs with vehicle type as a fallback. Electricity for charging company cars at your sites goes in Scope 2. Refrigerants (Scope 1): kilograms topped up in air conditioning, heat pumps and cold stores, from service engineers' records. Small leaks matter because some refrigerants have a very high warming effect. Generators and process emissions (Scope 1): fuel purchase records and any process that releases gases directly. Electricity, heat, steam and cooling (Scope 2): kWh per meter from bills or your supplier's portal, for every site. The GHG Protocol's Scope 2 Guidance asks for electricity to be reported two ways. The location-based method uses the average factor of the local grid. The market-based method reflects your contracts, so you also need your supplier's fuel-mix disclosure and any certificates you hold, such as renewable energy certificates (RECs) in the US or Guarantees of Origin in Europe. These are energy certificates, not carbon offsets. Where does Scope 3 data come from? The GHG Protocol splits Scope 3 into 15 categories, and few businesses need all of them. For many companies, particularly those that buy in most of what they sell, Scope 3 is the largest part of the footprint, so screen every category before choosing which to measure in detail. Typical sources: Purchased goods, services and capital goods: the accounts payable ledger grouped by spend category, or quantities from purchase orders. Fuel- and energy-related activities: derived from your Scope 1 and 2 data (fuel extraction, grid losses). Transport and distribution: carrier reports or freight invoices with weight, distance and mode. Waste: contractor reports in tonnes, split by treatment. Business travel: travel agency reports with routes and cabin class, mileage claims and hotel nights. Commuting and home working: a short staff survey on distance, mode and office days. Use and end of life of sold products: sales volumes plus product energy use and materials. First footprints usually mix three methods. Spend-based multiplies money spent by an environmentally extended input-output (EEIO) factor, an average emission intensity per unit of spend in a sector. Activity-based uses physical quantities such as tonnes or kilometres. Supplier-specific uses your suppliers' own emissions data and is the most precise when that data is sound. Data checklist by scope: sources and common gaps Data itemScopeWhere to find itCommon gap Gas and heating fuel1Supplier invoices, meter readingsEstimated reads, missing months Fleet fuel1Fuel cards, mileage logsLeased or hired vehicles left out Refrigerants1Maintenance recordsTop-ups not logged in kilograms Electricity2Bills, supplier portal, smart metersShared buildings where the landlord pays Purchased goods3Accounts payable ledgerSpend not mapped to categories Freight3Carrier reports, freight invoicesNo weight or distance recorded Business travel3Travel agency reports, expensesPrivate cars used for work left out Waste3Waste contractor reportsBin counts instead of tonnes Commuting3Staff surveyLow response rate How do you fill common data gaps? No first footprint has complete data. Fill gaps consistently and document them, so next year's figure is comparable. Missing months: extrapolate from the months you have, allowing for seasonal heating or cooling, and flag the figure as estimated. Shared offices: ask the landlord for building energy use and allocate your share by floor area or headcount. No supplier data: start spend-based, then replace the largest categories with activity or supplier data. Double counting: each cost belongs in one place; company-car fuel is Scope 1, not purchased goods. Changing factors: factor sets are updated regularly, so record the edition used. Keep a data log with the source, owner, date, unit and factor for each line, so the footprint can be audited and improved. Your first well-measured year becomes the base year for reduction targets; if you set one, the Science Based Targets initiative (SBTi) validates targets against its criteria but does not certify companies or footprints. Frequently asked questions What is the difference between Scope 1, 2 and 3 emissions? Scope 1 is direct emissions from sources you own or control, such as boilers and company vehicles. Scope 2 is indirect emissions from the electricity, heat, steam and cooling you buy. Scope 3 is every other indirect emission in your value chain, from purchased goods to the use of products you sell. Can I use spend data instead of activity data? Yes, especially for Scope 3 in a first footprint. Spend-based factors are sector averages, so they cannot reflect a lower-carbon supplier. Use them to find your largest categories, then move those to activity or supplier data over time. How accurate does a first business carbon footprint need to be? Accurate enough to show where your largest emissions are, and repeatable. Estimates are acceptable if documented and flagged. Accuracy should improve each year as metered or supplier data replaces estimates. Is reporting Scope 3 emissions mandatory? It depends on where you operate and your size. In the EU, mandatory CSRD reporting now applies to companies above both EUR 450 million turnover and 1,000 employees (Directive (EU) 2026/470), with simplified reporting standards (ESRS) from financial year 2027. Smaller firms are outside that scope, but larger customers often ask suppliers for emissions data for their own Scope 3 reporting. Does tree planting or buying carbon credits lower my reported footprint? No. Tree planting is a nature-based climate contribution with a modelled CO2 estimate, not an offset, and it does not reduce Scope 1, 2 or 3 figures. Certified carbon credits retired on public registries are a separate instrument; under the GHG Protocol they are reported separately, not deducted from any scope. For a rough first estimate before collecting detailed data, try Evertreen's CO2 calculator.
