ESG audit readiness: how should companies prepare in 2026?

Updated March 2026 - The expression "ESG audit" covers several different realities. For some companies, it means an internal review of ESG data and reporting processes. For others, it means preparing for the assurance of sustainability information. In both cases, the core issue is the same: the company must be able to explain where its data comes from, how it is calculated and who is accountable for it.

See also ESG indicators, Digitalisation of companies and The role of an accountant.

Internal ESG review

An internal ESG review is meant to test:

• ▸the consistency of the indicators;
• ▸the existence of supporting evidence;
• ▸the perimeter of the data;
• ▸the responsibilities for production and validation.

Statutory assurance mission

The H2A guidance reminds companies that the assurance mission on sustainability information covers, among other things, the double materiality process, compliance of the published information with the applicable framework and taxonomy-related information where relevant.

1. Governance of the reporting framework

Who decides, who collects and who validates? Without a clear governance map, ESG data becomes fragile very quickly.

2. Calculation methods

Each important indicator should point to a documented method: formula, unit, source, perimeter and consistency checks. A figure that cannot be traced back to a stable method is difficult to defend.

3. The audit trail

An ESG number should be traceable to evidence such as:

• ▸energy invoices;
• ▸HR registers;
• ▸HSE reports;
• ▸information-system extracts;
• ▸internal procedures;
• ▸supplier attestations.

Hayot Expertise insight: the best preparation for an ESG audit is not a polished report. It is simple, stable documentation shared between finance, HR, operations and management.

The recurring mistakes are easy to recognise:

• ▸publishing indicators without a written methodology;
• ▸changing the perimeter from one year to the next without explanation;
• ▸confusing marketing objectives with auditable data;
• ▸failing to archive supporting evidence;
• ▸producing the reporting too late in the closing calendar.

The H2A published an update to its guidance on January 20, 2026, applicable to the 2026 assurance work covering 2025 data. In parallel, the French Ministry of the Economy noted on February 4, 2026 that the Omnibus package was changing the CSRD landscape. That means companies need to stay both methodical and alert to regulatory developments.

A useful preparatory review is not about producing a glossy extra report. It is about identifying weak points in governance, definitions, evidence and timetable before publication or external review begins.

Prepare an audit or review of your ESG reporting

Successful ESG audit readiness rarely comes from a last-minute effort. It comes from clear governance, stable definitions, accessible supporting evidence and a controlled reporting calendar.

Do you want to identify the weak points in your ESG framework before publication or assurance? Our firm can carry out a pragmatic preparatory review focused on evidence and operational readiness. Book an appointment with an expert