On application, the supervisory authority may approve, for the ultimate participating insurance undertaking, the use of an internal group model applicable only to part of the group. This requires that both the ultimate participating insurance undertaking and the ultimate participating insurance undertaking of the sub-group are established domestically, and that the sub-group forms a definable part whose risk profile differs materially from that of the rest of the group. An application under the first sentence must be filed with the supervisory authority by 31 March 2022 at the latest.