The Role of External Assurance in Enhancing the Credibility of Sustainability Reports
DOI:
https://doi.org/10.61722/jaem.v3i1.9189Keywords:
External Assurance, Credibility, Sustainability ReportsAbstract
This study examines the role of external assurance in strengthening the credibility of sustainability reports using a qualitative systematic literature review (SLR) approach. A total of 30 peer-reviewed journal articles published between 2020 and 2026 and indexed in Scopus were analyzed based on predefined criteria, including relevance to external assurance in sustainability or ESG disclosure, English language, and full-text availability. The findings indicate that external assurance predominantly exerts a positive and substantive impact on reporting credibility. Specifically, 22 out of 30 studies report that assurance enhances disclosure quality, strengthens governance mechanisms, reduces information asymmetry, improves firm value, and increases stakeholder trust. These results are consistent with Stakeholder Theory, Agency Theory, and Legitimacy Theory, which position assurance as a mechanism of accountability, monitoring, and legitimacy building. However, 8 studies highlight symbolic or limited effects, particularly when assurance scope is constrained or regulatory frameworks are weak. Overall, external assurance demonstrates strong potential to enhance sustainability reporting credibility, although its effectiveness depends on regulatory quality, assurance standards, and corporate governance strength.
References
Bakry, A. E. A., Azhar, Z., & Kishan, K. (2025). The effects of amended sustainability reporting requirements on corporate social responsibility reporting and firm value: the moderating role of assurance. Journal of Financial Reporting and Accounting, 23(5), 1892–1924. https://doi.org/10.1108/JFRA-11-2022-0414
Boiral, O., Heras-Saizarbitoria, I., & Brotherton, M. C. (2019). Assessing and Improving the Quality of Sustainability Reports: The Auditors’ Perspective. Journal of Business Ethics, 155(3), 703–721. https://doi.org/10.1007/s10551-017-3516-4
Conradie, P., & Barac, K. (2025). Rational purpose requirement and sustainability reporting assurance. Sustainability Accounting, Management and Policy Journal, 16(7), 156–185. https://doi.org/10.1108/SAMPJ-04-2024-0399
Delgado Sánchez, V. P., Zorio-Grima, A., & Merello, P. (2026). Sustainability reporting assurance: Knowledge, lags, levels, and providers in leading global companies. Journal of Innovation and Knowledge, 12(November 2025). https://doi.org/10.1016/j.jik.2025.100899
Erin, O. A. (2025). Corporate governance, external assurance and integrated reporting practices: empirical evidence from South Africa. Meditari Accountancy Research, 33(7), 280–312. https://doi.org/10.1108/MEDAR-02-2024-2341
Farooq, M. B., & de Villiers, C. (2020). How sustainability assurance engagement scopes are determined, and its impact on capture and credibility enhancement. Accounting, Auditing and Accountability Journal, 33(2), 417–445. https://doi.org/10.1108/AAAJ-11-2018-3727
Freeman, R. E. (1984). Strategic Management: A Stakeholder Approach. Pitman.
García-Sánchez, I. M., Hussain, N., Aibar-Guzmán, C., & Aibar-Guzmán, B. (2025). ESG controversies and external assurance: Examining their impact on firm value and image. British Accounting Review. Advance online publication. https://doi.org/10.1016/j.bar.2025.101704
Jensen, M. C., & Meckling, W. H. (1976). Theory of the firm: Managerial behavior, agency costs and ownership structure. Journal of Financial Economics, 3(4), 305–360. https://doi.org/10.1016/0304-405X(76)90026-X
Khatri, I., & Kjærland, F. (2023). Sustainability reporting practices and environmental performance amongst nordic listed firms. Journal of Cleaner Production, 418 (January), 138-172.. https://doi.org/10.1016/j.jclepro.2023.138172
Krasodomska, J., Zarzycka, E., Street, D. L., & Grabowski, W. (2025). The impact of companies’ trust-building efforts on sustainability reporting assurance quality: insights from Europe. Meditari Accountancy Research, 33(7), 246–279. https://doi.org/10.1108/MEDAR-05-2024-2496
Kuo, L., Kuo, P. W., & Chen, C. C. (2021). Mandatory CSR disclosure, CSR assurance, and the cost of debt capital: Evidence from Taiwan. Sustainability (Switzerland), 13(4), 1–19. https://doi.org/10.3390/su13041768
Moreno, G. C. d. L., de Souza, M. P. M., Hein, N., & Giannetti, B. F. (2025). Sustainability report credibility and market performance of Brazilian companies. Social Sciences and Humanities Open, 11(December 2023), 101471. https://doi.org/10.1016/j.ssaho.2025.101471
MSuchman, M. C. (1995). Managing legitimacy: Strategic and institutional approaches. Academy of Management Review, 20(3), 571–610. https://doi.org/10.5465/amr.1995.9508080331
Obeng, V. A., Farooq, M. B., Miglani, S., & Jalali, F. (2025). Sustainability assurance quality and board gender diversity: moderating role of assurance level and provider type on the extent of assurance procedures. Journal of Accounting and Organizational Change, 21(7), 90–117. https://doi.org/10.1108/JAOC-07-2024-0214
Papadopoulos, G. (2026). The effect of external assurance on corporate carbon disclosures: Empirical evidence from Europe. Energy Economics, 153(October 2025), 109084. https://doi.org/10.1016/j.eneco.2025.109084
Pizzi, S., Venturelli, A., & Caputo, F. (2024). Restoring trust in sustainability reporting: the enabling role of the external assurance. Current Opinion in Environmental Sustainability, 68, 101437.
https://doi.org/10.1016/j.cosust.2024.101437
Prasetyawati, Tyas, Ferina, I. S., & Yusnaini Y. (2025). An Exploration of Sustainability Reports via Systematic Literature Review: An Analysis of Progress in Promoting Sustainability. DIJEFA: Dinasti International Journal of Economics, Finance & Accounting, 6(4), 2900–2908.
Roszkowska-Menkes, M., Aluchna, M., & Kamiński, B. (2024). True transparency or mere decoupling? The study of selective disclosure in sustainability reporting. Critical Perspectives on Accounting, 98, 102700. (December 2023). https://doi.org/10.1016/j.cpa.2023.102700
Sugiyono. (2021). Metode penelitian kualitatif, kuantitatif, dan R&D. Alfabeta.
Yan, M., Jia, F., Chen, L., & Yan, F. (2022). Assurance process for sustainability reporting: Towards a conceptual framework. Journal of Cleaner Production, 377(September), 134-156. https://doi.org/10.1016/j.jclepro.2022.134156










