Spend-based carbon accounting is the most common starting point for measuring business emissions because it uses data you already have in your accounts. Small adjustments the way accounting information is recorded and described makes it much easier to allocate spend to the right emission sources on the carbon accounting side.
This guide is designed to help business owners or sustainability teams work with their finance, accounting, or bookkeeping teams to identify small tweaks to accounting processes that can make a big difference in carbon footprint calculations.
By improving the way transactions are categorised and described, you can significantly improve the quality of your carbon accounting outputs.
Preparing your accounting for carbon reporting
The better your financial data, the better your carbon accounting will be. Two things matter most:
Clarity of transaction descriptions
Granularity of general ledger account names
1. Clarity of transaction descriptions
When you import financial transactions into Sumday, they arrive exactly as exported from your accounting system. If your account names and descriptions are vague, your results will be vague.
Tips for clearer data:
Ledgers: Avoid “Miscellaneous” or “General Expenses”. Use categories like “Travel – Flights”, “Office electricity”, “Software subscriptions”.
Vendors: Be specific — “Qantas – flights” instead of just “Travel”.
Descriptions: Add detail — “Return flight Brisbane–Auckland, economy” is much better than “Travel costs”. Where possible, include units from invoices in the description, e.g. “1,000 kWh electricity – quarterly bill” or “500 kg concrete – foundation pour”. This creates a clearer link between spend and activity, improving accuracy when allocating emissions.
2. Granularity of general ledger account names
Granularity means the level of detail in your accounts. More detail = more accuracy.
Example – Utilities:
Low granularity: “Utilities” → too broad.
High granularity: “Electricity”, “Gas heating”, “Water” → provides detail to make carbon reporting more precise.
So what’s next?
Take a look at your account names and input processes. Ask yourself:
Do my expense categories give enough detail?
Are vendor names clear?
Would an outsider know what the description means?
At Sumday, we back accountants and businesses to make carbon accounting part of everyday accounting. The more detail you put in now, the more useful your carbon data will be later.
Practical Checklist for Better Accounting Data
✅ Review your chart of accounts — avoid broad categories like “Miscellaneous” and consider breaking these down to more specific account names.
✅ Standardise supplier/vendor names — make sure suppliers are recorded consistently across transactions.
✅ Improve transaction descriptions — add details like travel routes, purpose, or type of service.
✅ Where possible, include units from invoices to help with Activity based calculations — e.g. “1,000 kWh electricity”, “500 kg concrete”.
✅ Separate combined categories — split “Utilities” into “Electricity”, “Gas heating”, and “Water”.
✅ Work with your accountant or bookkeeper — align on changes that make sense for both financial reporting and carbon accounting.