Here is a question that stops many businesses before they properly begin: what information do I actually need to collect? Carbon accounting can feel abstract until you are staring at a blank spreadsheet wondering whether to ask your logistics provider for fuel receipts or trawl through two years of electricity bills. The answer matters — and so does the quality of what you gather.
This post covers both sides of that question. First, a practical breakdown of the data categories your emissions inventory will need. Then, a clear-eyed look at why data quality is not a bureaucratic formality but the foundation on which your entire climate credibility rests. This is part of our Carbon Accounting & Net-Zero Series for sustainability-minded businesses.
The Five Core Data Categories
Most businesses — regardless of sector or size — will draw their emissions data from five primary categories. Understanding each one helps you know where to look and what format the data needs to be in.
1. Energy Consumption
This is typically your largest and most accessible data source. It includes:
- Grid electricity: Monthly consumption in kilowatt-hours (kWh), taken directly from electricity bills for every meter at every location you operate.
- Diesel for generators: Litres consumed, from fuel purchase records or generator maintenance logs.
- LPG and natural gas: Volume consumed (in kg or cubic metres), from supplier invoices.
- Renewable energy: If you have rooftop solar or have purchased Renewable Energy Certificates (RECs), note the generation in kWh — this will reduce your Scope 2 calculation under market-based accounting.
Energy data is usually the most reliable data in a first inventory because it comes from metered sources with paper trails. Start here.
2. Business Travel
Business travel sits in Scope 3 and can be surprisingly significant for service-sector businesses. You need:
- Flights: Departure and arrival airports, class of travel (economy/business), and number of passengers. Your travel booking platform or expense management system should hold this.
- Rail travel: Distance travelled or origin-destination data from booking records.
- Hotel stays: Number of nights, location (for regional emission factors).
- Company vehicle use: Total kilometres driven per vehicle, fuel type, and engine size.
3. Fuel Use in Operations
For manufacturing, logistics, and field-operations businesses, fuel is often a Scope 1 dominant. Track:
- Petrol and diesel consumed by company-owned vehicles and machinery (in litres)
- Fuel used in on-site industrial equipment or boilers
- Refrigerant gas top-ups (type and quantity in kg) — these carry high global warming potential and should not be overlooked
Fuel purchase invoices, petty cash records, and vehicle logbooks are your primary sources. For companies with large fleets, telematics data offers the most granular and accurate input.
4. Waste Generation
Waste-related emissions are often underestimated by first-time reporters. Relevant data includes:
- Weight of waste sent to landfill (in tonnes or kg), by waste type (paper, food, general)
- Weight of waste sent for recycling or composting (this reduces your footprint under most calculation methods)
- Wastewater volumes if you operate a manufacturing or food processing facility
Waste contractor invoices or Environmental Management System (EMS) records are the most reliable sources. For office-based businesses without formal waste contracts, reasonable estimates based on headcount and industry benchmarks are acceptable, provided you document the estimation method.
5. Procurement and Supply Chain
This is the most challenging category and the one that defines your Scope 3 completeness. Purchased goods and services — the raw materials, components, and contracted services your business buys — often represent 50 to 80 percent of a company’s total carbon footprint.
For a first inventory, use spend-based estimation: apply an industry-average emission intensity factor (in kgCO₂e per rupee spent) to your procurement spend by category. More accurate — but more resource-intensive — is supplier-specific data: actual carbon figures provided directly by your key suppliers. Building supplier engagement into your carbon accounting programme from year two onward is best practice. Your net zero strategy will only be as credible as the supply chain data underpinning it.
Why Data Quality Is Not Optional
Here is where a lot of businesses make a critical mistake. They treat their emissions inventory as an internal exercise — a number to report, a box to tick. As a result, they reach for the most convenient data sources rather than the most accurate ones. This is a problem, and increasingly an expensive one.
Carbon data quality matters for several reasons that go well beyond internal management:
Third-Party Verification and Reporting Standards
India’s BRSR (Business Responsibility and Sustainability Reporting) framework, mandatory for the top 1,000 listed companies, requires disclosure of Scope 1 and Scope 2 emissions and encourages third-party assurance. The Securities and Exchange Board of India (SEBI) has signalled a trajectory toward mandatory verification. When an independent auditor reviews your inventory, they will examine your data sources, your emission factor choices, and your calculation methodology. Inaccurate inputs are not just an embarrassment — they can result in material restatements and reputational damage.
Customer and Investor Due Diligence
Increasingly, large corporates — especially those with their own net-zero commitments — are asking suppliers to disclose their carbon footprint. If your number is based on rough estimates and outdated emission factors, procurement teams will notice. Businesses with well-documented, defensible inventories have a competitive advantage in B2B relationships where sustainability criteria are becoming part of supplier qualification.
The Garbage In, Garbage Out Problem
An emissions inventory built on low-quality inputs will not accurately reflect your real footprint. Worse, it may systematically undercount or overcount in ways that lead to poor strategic decisions. If your Scope 1 figure is understated because you missed a generator fuel category, your reduction plan will target the wrong interventions. If your Scope 3 spend-based estimate uses an emission factor from a different geography or industry, the resulting number is essentially fictional.
Good carbon data is not about perfection — it is about using the best available data for each source and being transparent about where estimates were used and why. That transparency is itself a marker of credibility.
Practical Data Quality Principles
Apply these four principles across every data category in your inventory:
- Prefer measured over estimated: Actual meter readings beat industry averages. Use estimates only where direct measurement is genuinely impractical.
- Use current emission factors: Match the emission factor vintage to your reporting year. India’s CEA grid emission factor, for example, is updated annually.
- Document everything: Record your data source, the emission factor used, the date of the factor, and any assumptions or estimates for every line in your inventory. This documentation is what turns raw data into an auditable record.
- Flag uncertainty: Where your confidence in a data point is low, note it. A qualitative uncertainty rating (high / medium / low confidence) beside each category helps readers and reviewers understand where the inventory is robust and where it has gaps to address in future years.
Building Better Data Over Time
Your first inventory will not be your best inventory, and that is entirely expected. The discipline of carbon accounting improves with each reporting cycle. In Year 1, you establish your boundary and methodology. In Year 2, you fill gaps identified in Year 1. In Year 3, you begin engaging key suppliers on their footprints. By Year 4 or 5, you have a credible, consistently-prepared inventory that can support science-based targets and public disclosure with confidence.
The organisations on the sustainability changemakers map — brands that have built genuine green credibility over years — did not arrive there through vague intentions. They built systems, collected data, and let evidence guide their decisions. Your emissions inventory is the first step in that same direction.
Start with what you have. Document what you do not. Improve every year. That is how carbon accounting data quality actually gets built — one honest inventory at a time.