Scope 3: the hardest 90% of your carbon footprint
For most organisations, the majority of emissions sit outside their own walls - in the supply chain, in the products they buy, in the goods they sell. Scope 3 is where the real footprint lives, and where measurement gets genuinely difficult. That is exactly where we come in.
Your emissions do not stop at your own front door
Scope 1 and Scope 2 cover the emissions you control directly - the fuel you burn and the electricity you buy. They are relatively straightforward to measure, and we handle them as part of your SECR reporting.
Scope 3 is different. It covers the emissions created across your entire value chain - the goods and services you purchase, the transport and distribution you rely on, the waste you produce, business travel, and the use of the products you sell. For most organisations, Scope 3 is by far the largest part of the footprint, often the overwhelming majority.
It is also the hardest to measure, because the data sits outside your business - with suppliers, hauliers and customers. That is why it deserves its own dedicated approach, rather than being treated as an afterthought to Scope 1 and 2.
Getting it right matters. Scope 3 is increasingly what customers, investors and procurement teams ask about - and it is where the biggest reduction opportunities are found.
Where Scope 3 emissions come from
- → Purchased goods and services
- → Transport and distribution, upstream and downstream
- → Business travel and employee commuting
- → Waste generated in operations
- → Use and end-of-life of products sold
- → Capital goods and fuel-related activities
Three methods, matched to the data you actually have
There is no single way to calculate Scope 3 - it depends on the quality of data available for each category. We use three established methods, choosing the most accurate one your data will support, and improving it over time.
Proxy
Where little direct data exists, we estimate emissions using a representative proxy - a comparable activity, average, or industry figure that stands in for the real number.
You are starting out, or a category has no usable primary data yet. It gets you a defensible baseline fast.
Spend-based
We apply emissions factors to the amount you spend in each category - turning financial data you already hold into an emissions estimate. Every business has spend data, so this method is always available.
You have clear financial records but not physical quantities. A strong, practical starting point for most categories.
Quantity × emissions factor
The most accurate method: we take the actual quantity of a material or activity - tonnes, litres, kilometres, units - and multiply it by a specific emissions factor for that item.
You have real physical data. This is where we aim to get to, category by category, as data improves.
The same ingredient, measured three ways
Take a bakery working out the emissions from the flour it buys. The method it can use depends entirely on the data it holds - and each step up improves accuracy.
An industry average
With no supplier data, the bakery starts with a representative average for flour of its type. Rough, but a defensible first baseline it can improve on.
What it spends on flour
Using the £ spent on flour in its accounts and an emissions factor per pound spent, the bakery gets a better estimate from data it already has to hand.
The tonnes it actually buys
Best of all, the bakery takes the actual tonnes of flour purchased and multiplies by a specific emissions factor for flour - the most accurate figure of the three.
The goal is not perfection on day one. It is a credible baseline now, then a clear path to move each category toward the most accurate method as better data becomes available.
A number means more when you can compare it
A Scope 3 figure on its own is hard to interpret. Is it high? Low? Typical for your sector? Our platform elexi answers that by benchmarking your emissions against your industry.
Drawing on published carbon data across UK businesses, elexi lets you compare your footprint against your peers - and cut it by the measures that matter to your operation, so you are comparing like with like.
That turns an abstract tonnage into something you can act on: where you stand, where the gap is, and where the biggest reductions are likely to come from.
Measurement is step one of the journey
Understanding your Scope 3 footprint is the foundation. From there, we help you set credible targets and build a plan to actually bring those emissions down.
Get a Scope 3 figure you can stand behind
Tell us a little about your business and our carbon team will show you how we would approach your Scope 3 footprint - the methods, the data we would need, and how it benchmarks against your industry.
Scope 3 emissions are reported in line with the GHG Protocol. Calculation methods and emissions factors are selected according to the data available for each category, and refined over time as data quality improves. Benchmarking is indicative and based on published industry data.