Other systemically important institutions (O-SII) buffer rates for ring-fenced banks and large building societies

O-SII buffer rates for ring-fenced banks and large building societies

The Prudential Regulation Authority (PRA) is requiredfootnote [1] to set Other Systemically Important Institutions (O-SII) buffer rates for ring-fenced banks (RFBs) and large building societies by applying the Financial Policy Committee (FPC)’s framework for the O-SII buffer.

On 29 July 2025, the FPC finalised the review of the O-SII buffer framework, confirming its decision to index O-SII buffer rate thresholds. The PRA has therefore reissued the O-SII buffer rates for 2024 to reflect this updated framework, as previously communicated.footnote [2] The revised 2024 O-SII buffer rates set out in this publication are based on the average of quarter-end UK leverage exposure measure (LEM) data over 2023 – assessed on a sub-consolidated basis for RFBs, and on a consolidated basis for building societies – and will apply from 1 January 2026.

The PRA has reissued O-SII buffer rates for the following RFB sub-groups, which apply to all exposures,footnote [3] on a sub-consolidated basis.

For RFBs, if the group is not subject to a global systemically important bank (G-SIB) buffer, or if the group has a G-SIB buffer rate that is lower than the O-SII buffer rate, there will be an increase in both the group PRA bufferfootnote [4] and the Leverage Ratio Group Add-on.footnote [5] This is to ensure that, where systemic buffers apply at different levels of consolidation, there is sufficient capital within the consolidated group, and distributed appropriately across it, to address both global systemic risks and domestic systemic risks.

Building societies

The PRA has reissued an O-SII buffer rate for the following building society, which applies to all exposures, on a consolidated basis.

Annex – RFBs in RFB sub-groups