may I provide an estimate if I don't have the exact figures

An estimate is permitted, provided you make that visible

Yes, an estimate is permitted in most cases — but not silently. In the VSME basic module of EFRAG, the voluntary standard that many clients use as a format for their sustainability questionnaire, a calculated or estimated value is often the only feasible answer, particularly for scope 3-like items where you depend on data from others. The point is not whether you estimate, but whether you show that you have estimated and on what basis.

Where this often goes wrong: someone enters an estimate as if it were a measured figure, without explanation. That is not necessarily untrue, but it is incomplete — and in a sample check or audit by your client, that difference will be noticed. For quantitative fields such as number of employees or turnover, where the client often expects a hard source document, the situation is different from an indicator that by nature allows for an estimate. Therefore, first check whether the field you are filling in asks for a measured value, such as the number of employees of the undertaking, or for an indicator that allows room for a calculation.

This is not established in a single article, but follows from the nature of the standard

There is no separate article that says "estimates are permitted" in so many words. The VSME basic module of EFRAG is designed as a simplified, proportionate standard for SMEs that do not fall under the full reporting obligation of Directive (EU) 2022/2464 (CSRD) — proportionality is the starting point there, not precision to the decimal place. That is a different kind of field from a registered fact such as the registration number under which the enterprise is registered, which comes directly from the Trade Register and leaves no room for interpretation. The distinction between "this is an established fact" and "this is a calculated indicator" thus determines whether estimating is appropriate — not a general rule about estimates themselves.