You do not need everything here to start. A first pass built mostly on spend is a legitimate footprint, and it tells you where to aim next. The items you cover with real activity data are the ones your number will hold up on.
Each table below gives the item, who usually holds it, and what it looks like when it arrives. Work down each table in order: they are sorted by how much accuracy each item buys you.
Scope 1: what you burn and leak
Refrigerants are the item most often missed. HFC leakage is Scope 1 and is often material for retail, hospitality, and cold chain, but it never appears in your accounts because you are billed for a service call rather than for the gas. Ask your maintenance contractor for top-up quantities by gas type.
Scope 2: the energy you buy
Both electricity figures matter. Your consumption drives the location-based number, and your contracts drive the market-based one. Both are required for a compliant inventory, so collect the contract alongside the bill.
Scope 3: everything your activity causes
These are the categories worth collecting directly, because they are usually material.
Not all of these apply to you. Capital goods matter if you bought vehicles, plant, or fitted out a building. Leased assets matter if you occupy space where the landlord holds the meter. Home working matters if a meaningful share of your team is remote.
Filling the rest with spend
Nobody collects activity data for every supplier, and no standard expects it. For the long tail of professional services, software, marketing, and office supplies, your accounting ledger covers it.
Connecting your accounting platform reaches all of it at once, which is why it is worth doing early even though it is not your most accurate input. Finance can usually authorise it in minutes.
Screening the categories you decide to skip
The GHG Protocol splits Scope 3 into fifteen categories. Most organisations have material emissions in three or four, and skipping the rest is legitimate.
What is not legitimate is skipping one you never looked at. A category you assessed and found immaterial is a finding you can defend. A category you never considered is a gap. Run your eye down all fifteen once, note which do not apply and why, and keep that note.
Where to go next
