What to Do When You Don’t Have 12 Months of Data

Introduction

Many first-time reporters discover that they don’t have a full year of sustainability data — and wonder whether they can still produce a CSRD-compliant report. The short answer: yes, you can.

Whether your business launched mid-year, changed systems, or only recently began tracking ESG information, the CSRD and VSME frameworks allow you to report using partial-year data, provided you are transparent about how it’s handled.

This article explains how to deal with incomplete data, estimate what’s missing, and stay aligned with EU reporting standards from the start.

If you haven’t yet built your data collection process, read our guide on how to integrate CSRD data collection into existing workflows first.

1. Why 12-Month Data Isn’t Always Available

It’s common for new reporters to have only part of a year’s data. Typical scenarios include:

• You started operations mid-year.
• You switched accounting or HR systems, losing older data.
• Utility bills or supplier records are missing for several months.
• You’re reporting voluntarily for the first time under VSME, using existing data sources.

The CSRD acknowledges that first-time reports may contain estimated or partial information, especially for SMEs and newly reporting entities. Transparency is what matters most — not perfection.

2. Report What You Have — and Explain What’s Missing

If you have only 6–9 months of reliable data, report that period clearly in your methodology section. For example:

“Data for energy and waste covers the period April–December 2025, as the company began recording sustainability metrics from Q2 onwards.”

You don’t need to “fill in” earlier months with guesswork unless the missing period significantly affects your totals. If you do estimate, explain how you did so (see below).

Always disclose:

• The exact period covered.
• Which data points are missing or estimated.
• The reason for partial coverage.

This is fully compliant with both ESRS 1 (general requirements) and VSME disclosure principles, which emphasise clarity and proportionality.

3. Estimating the Missing Periods (Optional)

If you want to show a 12-month equivalent for year-on-year comparability, you may estimate the missing months based on available data. Common methods include:

Always use conservative assumptions — it’s better to slightly under- than overestimate.

For more examples, see our guide on how to estimate missing data for CSRD reporting.

4. Label Partial-Year Data Correctly

When presenting results, clearly mark partial-year figures:

• Add a note in tables: “Data covers April–December 2025 only.”
• In charts, include footnotes indicating partial coverage.
• Avoid annualising figures unless clearly justified (e.g. seasonal businesses).

This clarity helps readers, clients, and auditors understand what the numbers represent and prevents misinterpretation.

5. Maintain Consistency for Future Reports

Once you’ve set a starting point, stick with it for future reporting. Next year’s report can include a full 12-month cycle and note that prior-year data covered only part of the year.

Example disclosure:

“Comparative data from 2025 covers only nine months due to the introduction of CSRD reporting processes mid-year.”

Consistency and transparency will make your future reports more robust and auditable.

Frequently Asked Questions

Can I submit a CSRD or VSME report with less than a year of data?

Yes. You just need to explain the reporting period and any estimation methods used. Partial-year data is acceptable for first-time reporters and SMEs.

Should I estimate the missing months?

Only if it helps give a fair picture of your operations. If your missing data represents less than 25% of the year, it’s fine to estimate using averages or trends — just document your approach.

How will auditors treat partial data?

Auditors or reviewers check for reasonableness and disclosure, not perfection. As long as your approach is clear and consistent, partial-year data will not be penalised.

What if I start collecting data mid-year?

Start now. Document your process and assumptions, and treat this as your “baseline year.” Future reports will show improvement and full-year comparability.

Key Terms

• CSRD – Corporate Sustainability Reporting Directive (EU 2022/2464) requiring companies to report on ESG topics.
• VSME – Voluntary Sustainability Reporting Standard for SMEs, offering simplified disclosures.
• Partial-year data – Sustainability information covering less than 12 months.
• Estimation – Using reasonable calculations or averages to fill missing months or gaps.
• Disclosure – Explaining how, when, and why data is reported.

Conclusion

Not having 12 months of data doesn’t disqualify you from reporting — it’s simply your starting point. Be transparent, use logical estimation if needed, and build your dataset over time. Every reporting journey begins with imperfect data; what matters most is consistency and continuous improvement.

When you’re ready to expand your data collection, check out our annual CSRD reporting calendar to plan your next full-year cycle.

To help you identify what data you have and what’s missing, use our checklist generator:

This tool will help you organise which data points you need and track what’s available for your reporting period.