why do I suddenly have to provide sustainability data to my customer

Your customer is part of the CSRD reporting chain

Your customer is usually asking this because they themselves are subject to Directive (EU) 2022/2464, the CSRD, and have a reporting obligation for which they need data from their entire supply chain — including suppliers who are not directly subject to that directive. This is called supply chain information: your customer must say something in their own sustainability report about the emissions, working conditions or risks associated with what they purchase from you. They cannot make this up, so they pass the question on to you.

For most SME suppliers there is no direct reporting obligation, but there is this indirect request from the customer. For this purpose, EFRAG VSME was developed: a voluntary, simplified standard specifically for unlisted SME enterprises, with a basic module that covers the most frequently asked points — energy consumption, employees, locations. If you recognize the question as something from that basic module, that is often the easiest starting point: many customer portals are based on it in substance, even if they do not themselves refer to the VSME name. Underlying business data — how many employees the undertaking has and in which countries the enterprise has establishments — appear in almost every ESG list, so you only need to have them clearly defined once.

Where this is stated in the directive

Your customer's obligation follows from Directive (EU) 2022/2464, which extends the scope of sustainability reporting to the value chain — this is the formal reason why the question reaches you, even without you yourself being subject to reporting obligations. The VSME basic module from EFRAG is not a legal obligation but a voluntary format; customer portals often choose it because it standardizes the questions that each portal would otherwise invent for itself.