T2S Release 4.3 – Introduction on 22 February 2021 – Update of scope


Note: This announcement, originally published on 20 November 2020, was updated to reflect the changed scope of the T2S Release. Changes have been highlighted.

Clearstream Banking AG, Frankfurt1 informs customers about the upcoming TARGET2-Securities (T2S) Release 4.3. According to the T2S Release Concept, the resolution for various T2S Problem Tickets (PBIs) will be deployed on

Saturday, 20 February 2021
for the business day Monday, 22 February 2021

T2S Release 4.3 - Scope

Based on the T2S status reporting end of December 2020, with the T2S Release 4.3, the resolution of 15 Problem Tickets is envisaged for a delivery in production. Four tickets have been prioritised by the T2S Operational Managers Group (OMG) and show the status “Candidate for T2S Release 4.3”. These tickets are currently being checked and can be authorised for the deployment.

CBF’s assessment related to these Problem Tickets shows that the fixes will not require software changes in CBF. More details are available in the attached file that provides the latest information about the related PBIs that might have impact on CBF’s customers acting in ICP and / or DCP mode. Customers are recommended to validate these scope elements and check whether operational and / or functional modifications in their procedures are required. Therefore, the latest file shows from the entire scope elements six PBIs that are already scheduled and will be deployed according to the T2S Service Transition Plan. The change to the last published list is highlighted in colour. The comparison shows that, “PBI 212104 – Partial Release instructions presented twice”, which was prioritised for a potential implementation in February 2021, is now scheduled to go live in June 2021 with T2S Release 5.0.

In urgent cases and if priority is given, further functional updates might be authorised for this deployment date. If changes in the scope of Release 4.3 are announced by T2S, CBF will publish an updated list of Problem Tickets closely before the implementation date. 

T2S Release 4.3 – Transition plan

The Market Infrastructure Board (MIB) will decide on the deployment of T2S Release 4.3 in production once the expected results have been shown during testing. On Tuesday, 9 February 2021, the final decision is to be made.

The deployment of T2S Release 4.3 into production is foreseen for the business day Monday, 22 February 2021. The implementation of the software will take place during the weekend within the T2S maintenance window. Meaning that currently no changes in the T2S Operational Day are expected; neither for the end of day (“EoD”) procedure on Friday, 19 February 2021, nor for the start of the business day, Monday, 22 February 2021.

The below table provides an overview of the important T2S milestones:

T2S Service Transition Plan – Activity for T2S Release 4.3


Deployment to UTEST

Friday, 15 January 2021

End of testing of scope elements in UTEST

Wednesday, 3 February 2021

Final approval of deployment to Production by MIB

Tuesday, 9 February 2021

Deployment to Production environment

Saturday, 20 February 2021

Customer 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 customer simulation environment (IMS23) remain unchanged.

Irrespective of whether CBF has to modify its software, CBF will maintain its link to the T2S Pre-Production environment (UTEST) so that customers can test on their demand. According to the ECB planning, the updated software will be installed on Friday, 15 January 2021 in UTEST. On this day UTEST and the connected test environments will be closed for the installation activities.


Please contact our Client Services teams for questions regarding the functionality. Questions related to the technical connection can be addressed to our Connectivity Support teams. Particular questions related to the T2S Release 4.3 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.