how do I politely write that I will not answer a question

Referring to the VSME standard works best

You politely decline a question by noting that the question goes beyond what the VSME standard requires, and by asking whether the purchaser can work with what is included in it. This is not seeking conflict, but a factual observation: since the amendment of March 2026 in the corporate sustainability reporting directive (CSRD), a company subject to reporting obligations may not demand more from a supplier with one thousand employees or fewer than what the voluntary EU standard for non-listed SMEs requires. A formulation that works identifies three things: which question is concerned, that this question falls outside the VSME core module, and the offer to answer the questions that do fall within it.

An example sentence: "This question on [subject] goes beyond what the VSME core module requires of a company of our size; can we drop this question, or can you explain on what basis you still need it?" That last part is important — it does not close the door entirely, and gives the purchaser the opportunity to explain why a question still belongs (for example, because the purchaser themselves is subject to a stricter reporting obligation). How such a conversation proceeds if the purchaser does not let it rest is described at my client does not accept that I refuse to answer a question. Which questions exactly fall within and outside the standard can vary from one questionnaire to another; that is what the cap check is for, described at what exactly is esgia's capcheck.

Where this boundary comes from

The boundary maintained here follows from the corporate sustainability reporting directive (Directive (EU) 2022/2464), which, with the amendment of March 2026, determines that companies subject to reporting obligations may not ask smaller suppliers for more than what the VSME standard from EFRAG contains; what a question precisely entails — and whether it concerns scope 1, 2 or 3 according to the GHG Protocol classification — helps determine whether it falls within the standard. More on what is in that standard and who it applies to is set out at what is VSME and what does it have to do with me.