Last updated: May 30, 2026. Small businesses are increasingly asked to measure greenhouse gas emissions because customers, lenders, investors, and large-company procurement teams need more climate data from their value chains. The business may not be directly covered by a mandatory reporting law, but it can still receive a customer request for Scope 1, Scope 2, Scope 3, renewable electricity, product or service-level emissions, or a methodology note.
Short answer: a small business does not need to start with a complex ESG platform or a full sustainability report. The useful first step is a clear, evidence-backed greenhouse gas inventory: define the boundary, collect energy and fuel data, screen relevant Scope 3 categories, apply credible emission factors, document assumptions, and prepare a simple methodology note that can be refreshed next year.
Why small businesses are being asked for emissions data
Most small businesses start measuring emissions because of a practical trigger. A customer sends a supplier questionnaire. A procurement team asks for emissions data before renewing a contract. A lender or investor requests climate information. A larger customer needs supplier data for Scope 3 accounting. Or the business wants to understand where energy, travel, logistics, waste, or purchased services are creating cost and emissions.
The important point is that the request is often narrower than a broad sustainability strategy. A small business may only need to prepare company-level Scope 1 and Scope 2 emissions, or a focused response for a customer. Other requests may need Scope 3 screening, service-level accounting, product data, or supporting evidence.
That is why the first question should be: what is the emissions calculation for? The answer changes the data needed, the level of detail, the timeline, and the deliverable.
Start with the GHG Protocol, but keep it practical
The Greenhouse Gas Protocol is the main global framework for corporate emissions accounting. For small businesses, the most relevant pieces are usually the Corporate Accounting and Reporting Standard, the Scope 2 Guidance, and the Corporate Value Chain (Scope 3) Standard.
You do not need to memorize the standards before starting. But the calculation should still follow their basic logic:
- define the organizational boundary;
- define the reporting period;
- separate Scope 1, Scope 2, and Scope 3 emissions;
- use activity data and credible emission factors;
- document assumptions and exclusions; and
- keep enough evidence to support the numbers.
For a fuller accounting overview, see Keslio's GHG Protocol guide and its guide to Scope 1, Scope 2, and Scope 3 emissions.
Step 1: Define the boundary
Before collecting bills, decide what the footprint covers. A small business should clarify:
- which legal entity or entities are included;
- which locations, offices, stores, warehouses, or sites are included;
- the reporting period, usually one financial or calendar year;
- whether the boundary follows operational control, financial control, or another approach;
- whether leased offices, coworking spaces, remote workers, or outsourced operations are included; and
- whether the customer request is asking for company-level, product-level, service-level, or site-level data.
This boundary does not need to be perfect on day one. It does need to be documented. If the footprint only covers one entity or one site, say that clearly. If estimates are used, explain them.
Step 2: Collect Scope 1 data
Scope 1 emissions are direct emissions from sources the business owns or controls. For many small businesses, Scope 1 data may include:
- fuel used in company-owned or controlled vehicles;
- diesel, petrol, natural gas, LPG, or other fuels used in generators, boilers, kitchen equipment, or machinery;
- refrigerant top-ups or leaks from air conditioning, refrigeration, or cooling equipment; and
- process emissions if the business has manufacturing or industrial activity.
Useful records include fuel invoices, fleet logs, odometer records, generator logs, maintenance records, and refrigerant service reports. If the business has no company vehicles, no onsite fuel use, and no refrigerant records under its control, Scope 1 may be small or zero, but the basis for that conclusion should still be written down.
Step 3: Collect Scope 2 energy data
Scope 2 emissions come from purchased or acquired electricity, steam, heat, or cooling. For most small businesses, electricity is the main Scope 2 source.
Start with electricity bills or meter readings for each site. Record the reporting period, kWh, utility provider, location, and currency or invoice references where relevant. If the business buys renewable electricity, green tariffs, renewable energy certificates, or similar instruments, keep the evidence separately.
The GHG Protocol Scope 2 Guidance distinguishes between location-based and market-based reporting. A small business may not need to go deep into this immediately unless a customer or reporting framework asks for it. But if the business wants to make a renewable electricity claim, it should keep the contracts, certificates, supplier information, and retirement evidence that support the market-based figure.
Step 4: Screen Scope 3 categories
Scope 3 covers other indirect emissions in the value chain. For small businesses, Scope 3 can feel overwhelming because data may sit with suppliers, employees, travel providers, landlords, customers, logistics partners, or finance systems.
A practical first step is not to calculate every category in detail. Start with a screen of the 15 Scope 3 categories and mark each one as likely material, potentially relevant, not relevant, or data missing.
Common small-business Scope 3 areas include:
- purchased goods and services;
- capital goods, such as equipment, computers, fit-out, or machinery;
- fuel- and energy-related activities not included in Scope 1 or Scope 2;
- transportation and delivery services;
- waste generated in operations;
- business travel;
- employee commuting and remote work assumptions;
- leased assets; and
- use or end-of-life of sold products where relevant.
If a customer only asks for Scope 1 and Scope 2, a Scope 3 screen may be enough for the first response. If the customer asks for Scope 3 categories, product data, or service-level emissions, the calculation needs to go further.
Step 5: Convert activity data into CO2e
Most emissions calculations use the same basic formula:
Activity data x emission factor = greenhouse gas emissions
Activity data can be kWh of electricity, litres of fuel, kilometres travelled, kilograms of refrigerant, tonnes of waste, spend by category, or supplier-specific emissions data. The emission factor converts the activity into greenhouse gas emissions. Results are usually expressed in carbon dioxide equivalent, or CO2e.
For example, if a cafe uses 10,000 kWh of electricity in a year and the relevant electricity emission factor is 0.5 kg CO2e per kWh, the location-based Scope 2 result would be 5,000 kg CO2e, or 5 tCO2e.
The formula is simple. The quality of the result depends on the boundary, data quality, factor source, unit conversion, and documentation.
Step 6: Build a simple evidence file
A small-business footprint should be easy to refresh. Keep a folder for the reporting year with:
- utility bills and meter readings;
- fuel invoices and vehicle records;
- refrigerant service records;
- travel, logistics, and waste records;
- procurement exports or spend summaries;
- supplier-specific emissions data if available;
- emission factor sources and versions;
- calculation workbook;
- methodology note; and
- assumptions, exclusions, and data gaps.
This evidence file is what makes the footprint useful for customers. It also prevents the next annual refresh from starting from scratch.
What if the customer asks for more than a company footprint?
Some customer requests ask for something narrower or more specific than a company-level footprint. Examples include:
- emissions linked to a specific service or contract;
- product carbon footprint information;
- supplier-specific emission factors;
- Scope 3 category data;
- CDP, EcoVadis, or portal responses;
- renewable electricity evidence;
- methodology documentation;
- consultant letters; or
- independent assurance or verification.
In those cases, do not assume a simple footprint will answer the request. Read the wording first. For supplier requests, Keslio can help through supplier request support. For Microsoft-specific requests, Keslio also offers Microsoft supplier GHG reporting support.
Reduction actions small businesses can consider
Once the first footprint is complete, the business can look for practical reduction actions. Common starting points include:
- improving energy efficiency in offices, kitchens, stores, or equipment;
- switching to renewable electricity where credible options exist;
- reducing fuel use in vehicles or shifting to lower-emissions transport;
- reducing business travel and improving remote-meeting practices;
- working with suppliers on high-impact purchased goods and services;
- reducing waste and improving recycling or composting where relevant;
- improving delivery routes, freight choices, and packaging; and
- setting a simple annual reduction target based on the first baseline.
Small businesses should avoid making claims that go beyond the evidence. It is fine to start with a baseline and a few practical actions. It is better to be clear and supportable than to overstate a net-zero or carbon-neutral claim.
Common mistakes to avoid
- Starting with offsets before calculating gross emissions.
- Publishing a footprint without a boundary, reporting period, or methodology note.
- Ignoring refrigerants, vehicles, or onsite fuel because the data is inconvenient.
- Claiming renewable electricity without keeping the certificate or contract evidence.
- Using spend estimates for everything when better activity data exists.
- Mixing company-level, product-level, and service-level emissions.
- Assuming Scope 3 can be ignored because the business is small.
- Changing calculation methods each year without documenting the change.
- Treating a consultant calculation as independent assurance.
How Keslio can help
Keslio helps small businesses and suppliers prepare practical GHG emissions calculations, evidence files, methodology notes, Scope 3 screens, and customer-ready responses. The goal is to produce a footprint that can actually be used: for a customer request, supplier questionnaire, sustainability report, annual refresh, or internal reduction plan.
If your team is preparing for customer sustainability requests more broadly, see Keslio's guide on what suppliers should prepare for sustainability reporting.
Need help measuring your small-business emissions?
If your team needs a practical emissions calculation without building a large ESG program, Keslio can help define the boundary, collect the right data, calculate Scope 1, Scope 2, and relevant Scope 3 emissions, and prepare a methodology note that is ready for customer review.
