Your first sustainability report: the most common mistakes and how to avoid them
An unclear boundary, numbers without a source, estimated readings, generic claims: the mistakes that leave a first sustainability report open to challenge and how to avoid them with the VSME standard.
A first sustainability report is almost always challenged for the same reasons: an unclear boundary, numbers that cannot be traced back to a document, incompletely calculated emissions and claims stronger than the data. You avoid them by starting from the documents the company already has, following the VSME standard and keeping every number linked to its source.
Why the first report is the hardest
The first report has no previous year to copy the structure from, it involves functions that do not usually work together, such as accounts, production, HR and purchasing, and it is often prompted by a specific request: a bank questionnaire, a tender, a large client. That is why the mistakes tend to repeat, and why they can be prevented.
The eight most common mistakes
1. Starting from the template instead of the data
You open a table of contents, write the text and look for the numbers at the end. The result is an elegant document with weak data. It is better to do the opposite: first gather bills, invoices, waste forms and workforce data, then write.
2. An undefined boundary
Which companies, which sites, which year? If the boundary is not written down at the start, energy, waste and workforce data end up referring to different perimeters. State it in the report and keep it the same for all indicators.
3. Numbers without a source
Every value must be traceable to the document it comes from. A kWh total without the bills behind it, or a headcount that differs from the payroll, is the first point a careful reader will challenge.
4. Estimated readings and misaligned periods
Bills with estimated consumption and later adjustments, invoices spanning two years, missing months. Reconstruct the twelve actual months of the reporting year before calculating any indicator.
5. Incomplete emissions
The classic mistake is stopping at the gas bill and the fleet and forgetting refrigerant gases, or reporting Scope 2 with only one method. To get it right, you will find the method in the articles on how to calculate Scope 1 and on the two Scope 2 methods.
6. Emission factors without source and year
An emission factor without a source makes the calculation impossible to verify, and changing factors from one year to the next without saying so distorts the comparison. Note the source, version and year of every factor.
7. Claims stronger than the data
“Sustainable company”, “zero impact”, 2030 targets without a plan: these are the phrases that expose you most to greenwashing risk, especially under the rules in force since 27 September 2026. Write what the data proves, with boundary and method.
8. Doing everything in the last month
Gathering a year of documents in a few weeks leads to estimates, gaps and shortcuts. Give the first report at least a few months and set up data collection so that the second year only needs an update.
A checklist before you submit the report
- The boundary is written down and is the same for all indicators.
- Every number has a source document you could show.
- Consumption covers twelve actual months, with no unverified estimates.
- Scope 1 includes fuels, fleet and refrigerants.
- Scope 2 is calculated with both the location-based and market-based methods.
- Emission factors with source and year.
- No environmental claim you could not back up with data.
How the VSME standard helps
The voluntary VSME standard, designed for non-listed companies, gives the first report a structure recognised by banks and clients: a Basic module with the essential disclosures, from B1 to B11, and a Comprehensive module with additional disclosures, from C1 to C9. Following it saves you from inventing a table of contents and makes clear which data you really need. For an example structure, read the article on the sustainability report for SMEs.
A first report holds up if every number has its source. Define the boundary, start from the documents, reconstruct twelve actual months, calculate Scope 1 and Scope 2 in full with stated factors and write only what the data proves.
Download the free sustainability report guide
In the free PDF guide you will find the VSME standard explained in plain words, what the first report involves, the 20 disclosures one by one and the most common mistakes, with a test to see where you stand. Download the guide to the sustainability report.
