do I have to answer the same sustainability questions again for each customer

The same fields come back, regardless of the sender

No, in most cases not in the sense that each answer must be built from scratch every time. The sustainability questionnaires from customer A and customer B differ in form — one portal calls it an "ESG questionnaire", the other calls it "supplier sustainability assessment" — but the underlying fields overlap strongly. Employment, emissions, energy consumption, water consumption and policy on working conditions come back in almost every list, simply because most customers base themselves on the same source modules. Once you have completed the basic module of the EFRAG VSME, you already have most of what comes in after that.

What does differ per customer is the granularity and the evidence that goes with it. One customer asks only for a percentage, another wants the underlying calculation or a third-party statement. And some customers ask further about scope 3 — the emissions from suppliers and in the use of the product — while others are satisfied with scope 1 and 2. That difference is not in the question itself, but in the level of detail the customer needs. A chain file with the source data in it — the company's annual turnover and the number of employees are often the basis for the rest of the calculation — prevents those figures from having to be looked up again for each list.

Why the overlap is structural: the CSRD chain

This overlap is no coincidence. Directive (EU) 2022/2464 (CSRD) requires large, listed companies to report on their entire value chain, including suppliers. Those large customers translate their reporting obligation into questionnaires for their suppliers, and often use the EFRAG VSME as a common basis — precisely because that standard was designed not to burden SMEs with dozens of incompatible formats. That is why the questions are similar, even if the sender changes.