Scope 1, 2 and 3 explained simply, and how SMEs get to Scope 3 data

Scope 1 represents direct emissions from owned or controlled sources, Scope 2 comes from purchased energy, and Scope 3 includes all other indirect emissions along the value chain. "Scope 1, 2, 3" sounds like a standard that only affects large corporations. In fact, this classification now appears in almost every supplier questionnaire, every EcoVadis assessment, and every voluntary sustainability report – even if there is no legal obligation forcing you to do so as a medium-sized business. Anyone who understands the three scopes clearly can answer any future inquiry in minutes instead of days.

This article explains the three scopes without regulatory jargon, shows you where most SMEs actually get stuck (Scope 3), and how to get reliable figures without launching an expensive consulting project.

Scope 1, 2 & 3 at a Glance

The classification originally originates from the international Greenhouse Gas Protocol and has established itself as the de facto standard – which is why it appears in practically every reporting format, whether VS (formerly VSME), EcoVadis, or an internal customer questionnaire.

The decisive difference for you as a business: you can determine Scope 1 and 2 relatively directly using your own meter and consumption data. Scope 3, on the other hand, occurs elsewhere – at your suppliers, your logistics, your customers – and that is exactly what makes it the biggest data challenge for SMEs.

Scope 1 – what is generated directly by you

Scope 1 includes everything you burn or emit yourself: the diesel in the vehicle fleet, the gas in the heating or production system, refrigerant leakages in cooling systems. The data source is usually simple – fuel receipts, gas bills, vehicle registration documents. Those who do not yet systematically record these values will usually find them within a day in the accounting department.

Scope 2 – purchased energy

Scope 2 maps the electricity and heat consumption that you buy but do not generate yourself. The calculation requires two things: your consumption (from the electricity bill or, better, from continuous measurement) and an emission factor for your energy mix. Those who have their own photovoltaics or green electricity contracts can noticeably reduce Scope 2 – a value that can be actively and quickly influenced, unlike Scope 3.

Scope 3 – the actual SME problem

Scope 3 is by far the largest and most complex category – for many businesses, it accounts for 70–90% of the total carbon footprint. It is divided into 15 subcategories, from purchased goods to transport to the use of sold products. For you as an SME, Scope 3 is relevant from two directions:

1. As a supplier: Your emissions are your customer's Scope 3 value. This is exactly why large buyers ask you for Scope 1 and Scope 2 data – they need it for their own reporting.

2. As a buyer: Your own suppliers, your logistics, and your pre-products are your Scope 3. If you want to create a complete carbon footprint yourself, you in turn need data from your suppliers.

This chain reaction is the reason why sustainability data in the supply chain is currently causing so much movement – it is also the core of what lies behind the request when your customer suddenly wants data from you. (For details, see: Your customer suddenly demands sustainability data?.)

Calculating Scope 3: the pragmatic path for SMEs

A complete Scope 3 carbon footprint across all 15 categories is complex, even for large companies. For medium-sized companies getting started, a more pragmatic approach is sufficient:

1. Prioritize instead of complete recording. First, identify the two to three categories with the greatest leverage – for manufacturing businesses, this is usually purchased goods and transport, in gastronomy often purchasing of goods and delivery logistics.

2. Start with spend-based data. Without primary data, Scope 3 can be roughly estimated using purchasing volume × industry emission factor. This is imprecise but a solid starting value – and can be transparently declared as an estimate.

3. Gradually switch to activity-based data. As soon as you know real quantities (kilometers, kilowatt-hours, metric tons), the footprint becomes more accurate. This is where continuous measurement pays off, instead of selective estimation.

4. Actively involve suppliers. The most accurate value comes from your own suppliers. Anyone who can already provide a clean Scope 1/2 answer themselves (see above) is also doing their own customers the same favor further up the chain.

Important for classification: A "wrong" Scope 3 value is rarely the problem – an unjustified or non-traceable value is. Auditors, buyers, and EcoVadis auditors are more likely to accept estimated figures that are clearly marked as estimates than completeness that cannot be proven upon request.

Why most SME carbon footprints fail at Scope 1 & 2 – before Scope 3 even begins

In practice, it often turns out that Scope 3 is not the first hurdle, but Scope 1 and 2 already are. The reason is simple – the data is scattered across invoices, meter readings, and Excel spreadsheets of individual locations and is painstakingly compiled once a year. With multiple locations, the effort multiplies, and the values are often already months old at the time of reporting.

This is exactly where strait comes in: Instead of reconstructing consumption data retrospectively from invoices, strait records electricity, gas, and heat consumption continuously via IoT sensors directly in the business – across locations and comparable in real-time. The first effect is immediate, visible cost savings because waste that gets lost in annual bills stands out. The second effect: A reliable, always up-to-date Scope 1 and Scope 2 basis is automatically generated from the same data – without manual post-recording at the end of the year.

This basis is also the foundation for Scope 3: Those who deliver clean Scope 1/2 figures as a supplier shorten the response time to customer inquiries from weeks to hours – and at the same time get ready for the next inquiry, regardless of the format in which it comes.

Do you want to know where you stand? With the CO₂ Footprint Quick Calculator you get a rough Scope 1+2 assessment including industry comparison in just a few minutes – as a starting point for the next customer inquiry or your first own report.

Scope 1/2/3 and the Value Chain Cap – a quick classification

A misunderstanding that frequently arises: The new Value Chain Cap limits how much data a large customer can demand from a supplier with up to 1,000 employees for its own statutory reporting – but it does not limit whether Scope 3 data is requested at all. EcoVadis assessments, voluntary questionnaires, and bank inquiries remain unaffected by this. Anyone who believes the cap makes the topic of Scope 3 irrelevant for SMEs is mistaken – it merely shifts one of several channels. (Full classification: Value Chain Cap – what it protects and what it doesn't.)

Ready for your first reliable Scope 1+2 value?

Try the free CO₂ Footprint Quick Calculator – or book a short demo where we show how strait automatically turns ongoing operating data into an auditable basis for Scope 1, 2, and the most important Scope 3 categories.

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