why do I suddenly have to complete a sustainability questionnaire for my customer

Your place in your customer's supply chain, not your own size

Your customer is usually not asking this because you yourself fall under the CSRD, but because they do — or will soon. Directive (EU) 2022/2464 requires large and listed undertakings to report on their supply chain, and "supply chain" also means: their suppliers. Your customer must therefore collect data about you to make their own reporting complete. That is the most common reason. A second, less discussed reason: some customers also use such a list to map supplier risks for their own procurement policy, independent of a legal obligation.

What exactly is being asked varies considerably by customer. Large buyers with their own CSRD obligation often ask broadly: energy consumption, emissions, working conditions in the supply chain, human rights policy. Smaller or medium-sized customers who do not themselves fall under the directive, but do feel pressure from their own customers, often keep it more limited and rely on the EFRAG VSME — the voluntary basic module for SMEs, with a more manageable question set than the full CSRD reporting. Evidence that frequently comes up includes energy bills, a CO2 calculation if you have one, and policy documents. If a piece is missing, "not yet available" is a more honest answer than an estimate you cannot substantiate. Questions about where your undertaking is active often link to this — see in which countries the enterprise has establishments for how that data is recorded — and the question how many employees the undertaking has also often comes up, because size determines how detailed the question list becomes.

Where that obligation comes from: the directive itself

The basis is set out in Directive (EU) 2022/2464, which imposes reporting obligations on the reporting undertaking over its entire value chain, including suppliers who are not themselves subject to reporting obligations. For the lighter alternative that many customers are now using, the EFRAG VSME is the designated source: that standard was specifically built to give SME suppliers a manageable, uniform format without the full CSRD burdens.