The European Securities and Markets Authority (ESMA) has published guidelines on performance fees in UCITS and certain types of AIFs which aim to harmonise EU supervisory practices. While generally aligned with current Central Bank of Ireland (CBI) requirements for UCITS, the guidelines are more detailed. Existing UCITS with performance fees will need to analyse whether adjustments will be necessary to comply with the guidelines. In-scope AIFs with performance fees will also need to look at the requirements. Our Asset Management & Investment Fund teams look at the guidelines in detail including who they apply to, when they are effective from, the key considerations for Irish managers, and the CBI's current position on UCITS' and AIF performance fees.