What this assumes about you
You work in finance, operations, or you are the person who ended up owning sustainability. You can get hold of company records and you can ask colleagues for things. You do not know what Scope 3 means and you should not have to before you start.What you will have at the end
A complete organisation footprint with a stated boundary, real data in the categories that matter, documented estimates everywhere else, and a sentence you can say out loud to a client or a board without hedging.The six lessons
1. What you are being asked for
Client request, tender question, or reporting obligation. They need different answers.
2. Draw the line
Decide what counts as your business. This decision drives everything after it.
3. Get a rough number fast
A complete but approximate footprint in an afternoon, so you know where to aim.
4. Upgrade what matters
Find your top three categories and get real data for those, and only those.
5. Check it before you trust it
Five checks that catch the errors which survive a casual read.
6. Share a number that holds up
State it with its boundary and method, so the first hard question does not undo it.
How long it takes
Reading the six lessons takes under an hour. Doing the work takes a few weeks, most of which is waiting for other people to send you things. Lesson 1 tells you which requests to send on day one so the waiting happens in parallel with everything else.Each lesson ends with a completion check. If you cannot tick it, do not move on. The lessons build, and a boundary you never wrote down will cause problems in lesson 5 that look like data problems.