The European Securities and Markets Authority (ESMA) published the results of its survey on legal entity identifiers, assessing the impact of allowing alternatives in reporting, disclosure or record-keeping requirements. Responses indicate a clear industry preference for continuing to use the Legal Entity Identifier (LEI) and highlight material costs for firms if additional identifiers were introduced. The survey drew 136 responses and found that adapting firms’ reporting systems to accommodate additional identifiers would be costly, averaging EUR 360,000 per firm with a median of EUR 40,000. A large majority of respondents (86%) preferred the LEI as the identifier for reporting, while pan-EU associations proposed improving EUID automation and interoperability with the LEI to reduce burden and avoid duplication. ESMA positioned the publication within its Data Strategy 2023–2028, focusing on consistent data standards and more cost-efficient reporting. ESMA will convene a follow-up workshop with survey respondents and other invited stakeholders to discuss the findings and possible future actions.