ESG Reporting at Mid-Sized Companies: From Excel to Software

How it works today at many mid-sized companies

Sustainability reporting rarely starts with software. It starts with a request: a bank wants figures on emissions, a major customer sends a supplier questionnaire, management wants to know what the CSRD means for the company. The task lands with one person who takes on the topic alongside their actual role – often in quality management, in controlling or in the management office.

That person builds their own tool. For the double materiality assessment, "Materiality_2025.xlsx" appears, with one sheet per topic, one column for the impact assessment and one for the financial assessment. For the carbon footprint, "GHG_Inventory_Draft.xlsx" follows, filled with electricity and gas bills, fuel card reports and emission factors that someone copied from a publication. Data from the departments arrives by email, as a photo of a meter reading or as a sentence such as "I'll send the fleet numbers next week".

In parallel a third file grows: "ESG_KPIs.xlsx" with headcounts, waste volumes and training hours, each column with a different source and a different reporting date. Which of these figures actually have to be reported depends on the materiality assessment – but that sits in another file, and the link between the two exists only in the head of the person in charge.

For a first overview that is sufficient. A spreadsheet is available immediately, and the first topics can be assessed quickly. It gets difficult in operation: the ESRS comprise ten topical standards from climate change to business conduct, each with its own sub-topics and disclosure requirements. For a company without a dedicated sustainability department, that range of topics is barely manageable alongside day-to-day business when every assessment, every figure and every justification sits in a different file.

The moment it becomes apparent

By the second reporting year at the latest, the weakness shows. Not all of the workshop participants are still with the company, the emission factor for natural gas has been updated in the meantime, and the inventory shows a total that nobody can trace back to the invoice anymore. Then the auditor asks why water was assessed as not material and who decided that – or the major customer wants to know on what basis the Scope 2 figure was calculated.

The spreadsheet holds a number, not a derivation. Not because anyone worked carelessly, but because structurally a spreadsheet knows nothing about the assessment scale, responsibility, factor version and approval. And a justification that exists only in one person's memory cannot be presented to any audit.

The target process in six steps

Sustainability reporting that holds up differs from a collection of spreadsheets not by more data, but by a fixed sequence in which materiality, data collection and report build on one another.

1. Define the reporting frame. It starts with organizations, sites and the reporting period. From these follow which entities fall within the reporting boundary and which transitional provisions apply. In preeco | sustainability the company category is derived from headcount, net revenue and the first CSRD reporting year; only the reliefs it permits are offered.

2. Set the scale in advance. Before anything is assessed, the materiality threshold is fixed – separately for impacts and for financial effects, with a written justification. That way every workshop assesses with the same scale.

3. Assess matters in a structured way. Every impact, risk and opportunity is recorded as its own record and assessed on both sides of double materiality, using scores or a written justification. The software calculates the result against the threshold; severe negative impacts become material even if the average lies below it.

4. Collect data where it originates. Once the materiality assessment is activated, the disclosure requirements that actually need to be filled are fixed. Figures are recorded with data quality and supporting documents; suppliers submit their emission data through a portal that requires no user account.

5. Calculate the carbon footprint instead of typing it. The greenhouse gas inventory follows the GHG Protocol: Scope 1, Scope 2 location- and market-based, and all 15 Scope 3 categories. Emission factors are suggested from stored databases, and every record keeps the factor edition it was calculated with. When energy data changes, the system recalculates the affected emissions.

6. Generate the report and freeze it. The disclosure report takes its figures directly from the data collection modules. Non-material sub-topics receive an omission note stating the reason. On finalization a snapshot with a cryptographic checksum is stored, so that later changes are detected.

What the audit actually wants to see

An auditor rarely asks about the report alone. The question is about a specific disclosure – the Scope 2 emissions, say, or a topic assessed as not material – and about the path that led to it: assessment, threshold, data basis, factor, responsible person, time of the change. In a collection of spreadsheets this information sits in several files and mailboxes. In preeco | sustainability the activity history records who changed which value and when, with before and after values.

Before and after compared directly

What the switch means in practice

The most common objection is that the work done so far would be lost. That is not the case. The workshop assessments, the consumption data collected and the justifications remain the substantive basis; they are transferred into a structure that records scale, origin and responsibility. Organizations and facilities can be taken over by Excel import with column mapping. What stands out in the process are the gaps – and it is better to see them now than in the audit.

The larger effort lies not in the technology but in clarifying the substance: which entities belong in the reporting boundary, who supplies which data, and who decides on materiality. Plan time for this before the first values are recorded.

Three mistakes that make the switch unnecessarily hard

Starting with the figures. Anyone who collects data on every topic first gathers a lot that does not have to be reported after the materiality assessment. The assessment comes first because it determines the scope.

Planning to add the justification later. Assessing a topic as not material is a decision that gets audited. Record the justification when the decision is made – not when someone asks for it.

Leaving everything with one person. If a single person keeps collecting and transferring all the figures, the problem merely moves to a different interface. The data belongs where it originates: fleet, facility management, HR, purchasing.

How to tell that it is time

Excel templates are not a mistake for a first overview. They turn into a risk once at least one of these points applies:

• Customers, banks or your own reporting obligation regularly require ESG data.
• More than two departments contribute data.
• You cannot show why a topic is considered not material.
• The carbon footprint cannot be traced back to the factor and the invoice.
• Several entities or sites belong in the reporting boundary.

If none of these apply, the templates will do for now. If two or more apply, they are already working against you.