How can your company join the BIST Sustainability Index?

The BIST Sustainability Index brings together companies with strong environmental, social and governance (ESG) performance. Participation is voluntary, Borsa İstanbul covers the assessment costs, and only publicly available data is used. Companies pay no assessment fee, but the quality of their public disclosures is decisive. For companies seeking inclusion, the process can be summarised in six steps.

Check your eligibility.

The index is open to companies listed on the BIST Stars, BIST Main and BIST SubMarket. First, confirm that your company is listed on one of these markets. To participate in the assessment, submit a written request to Borsa İstanbul's Index Directorate. There is no cost to the company for this step.

Strengthen your public disclosures.

LSEG, formerly Refinitiv, conducts the assessment using publicly available information only. Your sustainability report, annual report, corporate governance compliance report and relevant website content therefore play a decisive role. Publishing a TSRS-compliant sustainability report and transparently disclosing policies and performance data directly affect your score. A practice that has not been publicly disclosed will not be recognised in the assessment.

Make effective use of the LSEG ESG Contributor Tool.

Companies enter their public sustainability data and links to the underlying sources into the web-based LSEG ESG Contributor Tool. A user profile must first be created, and multiple users can be registered for a company. Keeping submitted information accurate and up to date is essential.

Meet the scoring criteria.

To qualify for the BIST Sustainability Index, all three conditions below must be met under the legacy methodology, which is being applied in parallel during the transition to the new methodology:

• An overall sustainability score of 50 or above.
• A score of 40 or above in each of the environmental, social and governance pillars.
• Scores of 26 or above in at least eight categories.

The BIST Sustainability 25 Index has higher thresholds: an overall score of at least 70, at least 60 in each pillar and at least 50 in eight or more categories.

Data and scores from the previous two calendar years are considered. Meeting the criteria in at least one of those years is sufficient.

Follow the index calendar.

There are four index periods each year: January–March, April–June, July–September and October–December. Constituents are determined using the current ESG scores available on the LSEG terminal on the first Monday of December, March, June and September.

Maintain continuity

A company that fails to meet the criteria in one period is given one index period to recover. Failure to meet the criteria for two consecutive periods leads to removal from the index. Regular data updates and consistent sustainability performance are therefore essential.

Practical ways to improve your score

• Publish a comprehensive sustainability report on time.
• Formalise policies on climate, human rights, diversity and ethics, and demonstrate how they are implemented.
• Obtain independent assurance, which can have a positive effect on your score.
• Strengthen board composition, the proportion of independent directors and transparency practices.
• Prevent incidents such as environmental fines and ethical breaches, which can lower your score.

A final thought

Companies that follow these steps systematically can significantly improve their prospects of joining the BIST Sustainability Index. Inclusion strengthens investor perceptions and provides tangible evidence of a company's sustainability maturity.

At Finar, we would be pleased to support you throughout the process, from assessing eligibility to preparing your reports.