CarbonTrail automatically assigns a carbon category to your expenses by analysing the types of businesses you work with. For example, it recognises that Z Energy or BP are fuel suppliers, or that Spark is a telecommunications provider. However, because every business and accounting system is unique, some supplier categorisations may need a second look.
Reviewing your suppliers ensures your carbon footprint is as accurate as possible.
Getting Started
From the Measurement Roadmap, click Review Suppliers. This displays the full list of suppliers imported into CarbonTrail, including:
Supplier name
Category / emission factor assigned
Spend from your accounting tool
Emissions estimate (spend × emission factor)
Understanding Category Badges
Purple badge – The category was assigned by AI based on industry averages.
Blue badge – A custom emission factor has been created for this specific supplier, sourced from their own sustainability and financial reporting. This is more accurate than the industry average.
Changing a Supplier's Category
If a category doesn't look right, click the pencil icon next to the supplier to update it.
Tip: When choosing the right category, think about the goods or services you predominantly purchase from that supplier. For example, The Warehouse could be categorised as Stationery.
Once you save the change, the supplier's emission factor will update and it will be repositioned in the list.
Ignoring Suppliers That Don't Affect Your Footprint
Some transactions in your accounting tool may have no bearing on your carbon footprint. Common examples include:
Internal stock movements
Dividends
Internal fund transfers
For these, click Ignore from Inventory — they will be excluded from your carbon calculations.
Paying individuals?
If paying someone as a salary, you can ignore them.
If paying someone as a contractor who works across multiple businesses, they should remain on the list.
Completing the Review
Once you've checked all suppliers and resolved any errors, click Complete Supplier Review.