What is TSRS and Sustainability Assurance?
Sustainability reports show how a business balances its economic returns with its social and environmental impact, giving stakeholders information that financial statements cannot. With the Turkish Sustainability Reporting Standards (TSRS), this reporting has moved from voluntary to mandatory for companies within scope, and independent assurance of the reports has come onto the agenda.
ARSEN covers the process end to end, from reporting readiness to the assurance engagement. By reviewing your data collection infrastructure, internal controls and calculation methods through an auditor's eyes, we help you get through your first assurance year without surprises.
What does our TSRS and Sustainability Assurance work include?
Scoping
- Determining whether the company falls within the TSRS scope under the lists and thresholds in the POA decision
- Two-consecutive-period threshold test and group-level assessment
- Mapping out the first reporting period, transition reliefs and the assurance timetable
Readiness
- Gap analysis against TSRS 1 (general requirements) and TSRS 2 (climate-related disclosures)
- Materiality assessment and setting reporting boundaries
- Data collection processes and internal control design
- Dry-run assurance
Assurance
- Limited and reasonable assurance of sustainability reports
- Verification of the greenhouse gas inventory (Scopes 1, 2 and 3)
- Assurance of sustainability indicators in integrated and annual reports
- Briefings for the board of directors and the audit committee
ESG and voluntary reports
- Independent assurance of ESG reports prepared under GRI or other frameworks
- Data verification for ESG ratings and investor questionnaires
- Verification of sustainability-linked loan and green bond indicators
- Preparing embedded emissions data for CBAM
Get a tailored proposal for TSRS and Sustainability Assurance
Share the scope in a few lines and we will send you our team, timeline and fee proposal in writing. Free of charge and non-binding.
- Under founding-partner supervision
- Member of the SFAI international network
- Written, transparent proposal
or call: +90 212 951 02 47
Who must prepare a TSRS report?
The application thresholds were raised by the POA's decision of 13 January 2026 (Official Gazette, 16 January 2026, No. 33139). For financial years beginning on or after 1 January 2025, entities included in the lists annexed to the decision that exceed at least two of the three criteria below in two consecutive reporting periods prepare a sustainability report under the TSRS.
| Criterion | Previous threshold | Current threshold |
|---|---|---|
| Total assets | TRY 500 million | TRY 1 billion |
| Annual net sales | TRY 1 billion | TRY 2 billion |
| Number of employees | 250 | 500 |
Some entities, such as banks, are in scope regardless of size. The current text of the Board decision should be relied on for the lists and exceptions. Let us assess together, using two periods' figures, whether you are in scope.
TSRS readiness timetable
| When? | What needs to be done? |
|---|---|
| Start of the reporting period | Scoping, TSRS 1 and TSRS 2 gap analysis, identifying data owners |
| During the period | Running data collection and control processes, emission calculations, dry-run assurance |
| Period end | Draft report, consistency check with the financial statements, board approval |
| After the report | Independent assurance engagement, assurance report and publication |
The most common mistake is trying to collect data after the period has ended. An assurance engagement needs to show that data was collected in a controlled way throughout the period.
The difference between an ESG report and a TSRS report
ESG is a broad framework covering environmental, social and governance matters; ESG reports prepared under standards such as GRI are mostly voluntary and address a wide range of stakeholders. TSRS, by contrast, is investor-focused reporting based on the ISSB standards and mandatory for companies within scope; it focuses on the financial effects of sustainability risks and opportunities and must be connected to the financial statements.
Companies outside the scope may still need to produce ESG data because of lenders, investors and export customers. ARSEN provides independent assurance on both TSRS reports and voluntary ESG reports under ISAE 3000 and ISAE 3410.
How do we work?
- Clarifying scopeWe determine your reporting obligation, the level of assurance and the timetable.
- Gathering evidenceWe obtain sufficient appropriate evidence against the criteria at process, control and data level.
- Assurance reportWe provide an evidence-based assurance report and recommendations for improvement.
Who needs TSRS and Sustainability Assurance?
- Companies and banks within the scope of the TSRS
- Organisations publishing a sustainability or ESG report voluntarily
- Companies using green finance and sustainability-linked loans
- Manufacturers whose export customers require carbon reporting
Which standards is TSRS and Sustainability Assurance based on?
Frequently asked questions about TSRS and Sustainability Assurance
Is my company within the TSRS scope?
We prepare an ESG report; do we also need to comply with the TSRS?
What is the difference between limited and reasonable assurance?
When should we start preparing?
How can I get a proposal for TSRS and Sustainability Assurance?
Last updated: October 22, 2026