Scope 3 is the part of a sustainability questionnaire that concerns CO2 emissions that arise outside your own company, but are related to what you purchase, produce or supply. Think of emissions from your own suppliers, the transport of raw materials, or the use of a product after you have delivered it. Your customer asks about this because for most companies scope 3 accounts for the largest part of their total carbon footprint, often larger than their own scope 1 and 2 combined.
The division into scope 1, 2 and 3 comes from an international accounting framework for greenhouse gas emissions, the Greenhouse Gas Protocol. Scope 1 is direct emissions, for example from your own vehicles or heating. Scope 2 is emissions from purchased energy, such as electricity. Scope 3 is everything around that: the supply chain before and after your own activities. For a supplier, this often means that your own emissions count as scope 3 at your customer, which explains why that customer asks for your figures in such detail.
Why scope 3 is the most difficult part
Scope 1 and 2 are relatively easy for a company to measure: you know how much fuel or electricity you consume. Scope 3 requires data from others, such as your own suppliers, transporters or customers for your product. Not every SME keeps this data in detail, and not every link in the chain provides the same kind of figures. As a result, many companies work by necessity with estimates, for example based on turnover or weight of purchased materials, instead of exact measurements.
This distinction between measured and estimated data is precisely what customers often ask about: not just a figure, but also how that figure was arrived at. A questionnaire might for example ask whether you have already partially mapped scope 3, which categories you include, and whether this is based on estimates or actual data. For smaller suppliers, a first, rough estimate is often a useful starting point, without immediately expecting a fully measured scope 3 figure.
How scope 3 relates to VSME
Companies that fall under the voluntary reporting standard for small enterprises, VSME, often encounter the same scope division again in their own reporting. A customer who must report themselves asks their suppliers for the data to complete their own scope 3. This creates a chain of questionnaires that are each structured slightly differently, but essentially ask for comparable information. Anyone who once has a basic file with their own scope 1, 2 and a first estimate of scope 3, can reuse that file instead of answering each list from scratch again.
Whether a specific question in a questionnaire concerns scope 3 or another part of the reporting is not always immediately clear from the customer's wording. In the knowledge bank with explanations by topic common terms from these questionnaires are listed, so you can recognise a question more easily before you start filling it in.
What this means in practice for a supplier
For an installation company, a wholesaler or a service provider, a question about scope 3 usually does not mean that a full climate accounting is expected. It is often about whether you know which categories are relevant for your company, and whether you have started recording the main items, such as fuel consumption of subcontractors or the origin of purchased materials. Supervisors and customers do not apply a fixed standard that is the same for every company; what is asked depends on the sector and the size of the customer themselves.
Because scope 3 involves data from multiple parties in the chain, it is also a subject where evidence becomes outdated faster than with one-off declarations: an assessment from last year can already be superseded by a new supplier or a different transport contract. With the recognition check of a few questions you get a first indication of which topics are relevant for your business, including scope 3, without this constituting an assessment of your situation.
For the precise obligations that apply to your own business, it is advisable to consult the official text of the Greenhouse Gas Protocol or the VSME Directive, or to involve a lawyer or advisor who knows your specific situation. Supplia.eu does not declare, certify or assess anything; the platform helps with recognizing questions and reusing answers from one chain file.
If you want to know how data from your file is traced to a specific question in a questionnaire, you can read that on the page how the information is created. If you are still unsure whether scope 3 is relevant for your business, check the frequently asked questions about sustainability reporting or take the free quick-scan to see in a few minutes which topics apply to you.