CSSF Repeals Circular IML 91/75: Circular CSSF 26/912 Replaces Long-Standing Luxembourg UCI Rules

On 22 May 2026, the CSSF issued Circular CSSF 26/912, repealing Circular IML 91/75 with immediate effect. IML 91/75 had originally defined the rules applicable to Luxembourg undertakings for collective investment (UCIs) under the Law of 30 March 1988.

The repeal reflects the evolution of the UCI regulatory framework since IML 91/75 was first published. According to the CSSF, several chapters had already been repealed and replaced by other CSSF circulars, while others had become outdated due to national or EU legislation or had been absorbed into the CSSF’s administrative practice. The circular had also been amended multiple times, including by Circulars CSSF 05/177, 18/697, 21/790, 22/811 and 25/901, before being archived on 22 May 2026 with the entry into force of Circular CSSF 26/912.

The new circular applies to all Luxembourg UCIs and parties involved in their functioning and control, including credit institutions, SICARs, investment firms, investment fund managers, SIFs, specialised PFS, UCITS and Part II UCIs. It covers areas such as accounting, NAV calculation, outsourcing and UCI administration.

Practically, the repeal means that the rules previously contained in IML 91/75 no longer apply. The relevant matters are now governed by other CSSF circulars, national and EU legislation, or the CSSF’s administrative practice. Firms should therefore review internal policies and procedures that still reference IML 91/75 and align them with the current regulatory sources.

Market participants may particularly wish to:

• review policies, manuals and outsourcing arrangements for outdated references to IML 91/75;

• reassess documentation relating to accounting, NAV calculation, outsourcing and UCI administration to avoid regulatory gaps; and

• monitor whether the CSSF issues further guidance, for example through FAQs or additional circulars.

Although the repeal is unlikely to create substantive regulatory gaps, Circular CSSF 26/912 serves as a useful reminder to refresh regulatory mapping, especially given that IML 91/75 had been a key reference point in Luxembourg’s fund industry for more than 30 years.

Recommendation:

Affected firms should review internal policies, procedures and outsourcing arrangements following the immediate repeal of Circular IML 91/75 by Circular CSSF 26/912. Areas previously covered by IML 91/75, including UCI accounting, NAV calculation, outsourcing and UCI administration, are now governed by other CSSF circulars, national and EU rules, or the administrative practice of the CSSF.