OneClearstream rollout documentation


The OneClearstream service rollout related client documentation can be found consolidated on this page by topic and market.

Further documentation will be added as more market links are activated.

Clients can obtain details on specific T2S In-CSD securities accepted in OneClearstream by means of a simple query via the Clearstream Codelist - Securities Database.

For Local Market Partner (LMP)-specific search criteria please refer to Announcement C20056.

OneClearstream service description

Clients with CBF CASCADE accounts should refer to:

  • The OneClearstream Client Handbook that describes the OneClearstream asset servicing processes for clients of Clearstream Banking Frankfurt using the OneClearstream service.
  • The  OneClearstream Asset servicing - CBF issued securities  document that describes the OneClearstream asset servicing processes for CBF as the Issuer-CSD. 
    Note: As part of the Corporate Action Harmonisation (CAH) Project as of 3 July 2023, asset servicing for CBF-issued securities has been upgraded to OneClearstream Asset Servicing level (CAH – KADI DE migration to OneCAS) and is mandatory for all clients with CBF, CBF-i and CBL accounts. This applies only to migrated CBF-issued securities and respective events. For details, clients should refer to the respective announcements and Detailed Functional Specifications which are provided below in the market-specific migration information for the German market.

Clients with CBL or CBF-i accounts are informed about the changes to the existing services via Release information and dedicated announcements. 

Subscription forms

Xact Web Portal documentation

Documentation and video tutorials can be found on the Xact Web Portal documentation page.

Market-specific migration information

Finland – OneClearstream service activation for Euroclear Finland

Activation date: 27 November 2023

The OneClearstream service will be activated for securities issued by Euroclear Finland (EFi). Hence, all Finnish securities will be eligible in Clearstream Banking AG (CBF) and LuxCSD S.A. All Finnish ISINs will receive collective safe custody (CSC) status.

Clearstream Banking will continue to access the Finnish market via Clearstream Banking S.A.'s (CBL's) direct link to Euroclear Finland.

CBF accounts

CBL or
CBF-i accounts


D23027: Finland: OneClearstream service activation for Euroclear Finland – Update

C23018: Finland: OneClearstream service activation for Euroclear Finland – Update

Impacted ISINs

List of migrated ISINs

Germany – Mandatory asset servicing upgrade to OneClearstream asset servicing level (CAH – KADI DE migration to OneCAS)

Activation completed (3 July 2023)

CBF accounts

CBL or
CBF-i accounts

Cut-over announcements

D22016: "Corporate Actions Harmonisation - KADI DE migration to OneClearstream Asset Servicing (OneCAS)" - Update

C22009: "Harmonisation of Clearstream Banking’s asset services" - Update

C22039: Harmonisation of Clearstream Banking’s asset services – German choice dividend event – New process - Update

Detailed Functional Specifications

CAH KADI DE Migration to OneCAS - Detailed Functional Specifications

Eurobonds – activation completed

Activation date Step 1: 22 March 2021

Activation date Step 2: 19 April 2021

CBF accounts

CBL or CBF-i accounts

Cut-over announcement

C20043: "Eurobonds eligibility in T2S  - Phase 2 - update"

Impacted ISINs

List of eligible Eurobonds ISINs - Step 1

List of eligible Eurobonds ISINs - Step 2