T2S Problem Release: Introduction on 19 September 2023 – Final update


Note: This Announcement, originally published on 24 May 2023 and amended on 7 July 2023, has been further updated to reflect the final scope of the T2S Release. Changes have been highlighted.

Clearstream Banking AG, Frankfurt,1 informs on the upcoming TARGET2-Securities (T2S) Problem Release in September 2023 (R2023.SEP). According to the T2S Release Concept, the release will be deployed on 

Saturday, 16 September 2023
for business day Monday, 18 September 2023

T2S Release R2023.SEP – Scope

Based on the T2S status reporting of mid-September 2023, the T2S Problem Release R2023.SEP is planned to solve 23 Problem Tickets in production, eight of which are relevant for CBF clients acting in DCP mode. Three of the said fixes affect adaptations to the graphical user interface (GUI). One further PBI possibly affecting CBF clients operating in ICP or DCP mode has been added to the scope. CBF’s assessment related to these Problem Tickets shows that the fixes will not require any changes in CBF’s software. The list attached shows an overview of the PBIs.  

T2S Release R2023.SEP – Transition plan

On 6 September 2023, the Market Infrastructure Board (MIB) decided that the T2S Release R2023.SEP will be deployed to production.

The implementation of the software will take place during the weekend’s T2S maintenance window – meaning that currently no changes to the T2S Operational Day are expected for the End of Day (EOD) procedure on Friday, 15 September 2023, or for the start of business day Monday, 18 September 2023.

Client simulation

The simulation activities will be conducted in a “free simulation mode”. The already established static data for CBF accounts and the related connectivity settings in the CBF client simulation environment (IMS23) remain unchanged. Details about the availability of the client simulation environments IMS23 and UTEST can be found here


For further information, clients may contact Clearstream Banking Client Services or their Relationship Officer. Questions related to the technical connection can be addressed to Connectivity Support. Particular questions related to the production launch in September 2023 will be routed to the experts of the T2S Settlement Functionality team.


1. This Announcement is published by Clearstream Banking AG (CBF), registered office at Mergenthalerallee 61, 65760 Eschborn, Germany, registered with the Commercial Register of the District Court in Frankfurt am Main, Germany, under number HRB 7500.