Xact via SWIFT: New settlement validation rule - Unique sender’s message reference - Update


Note: This announcement originally published on 22 May 2021, has been updated to provide customers with further information on the validation process. Changes have been highlighted. 

Clearstream Banking1 informs customers that effective

22 November 2021

in order to limit the risk of instruction’s rejection for customers, it has been decided to add the common code parameter to the validation process. However, if possible, customers are still encouraged to have a unique reference independent of the common code.

A new settlement validation will be put in place to ensure that the sender’s message reference mentioned in the settlement instruction is unique. Clearstream Banking will no longer accept two settlement instructions pending/failing with the same sender's message reference for a given common code. This will remain valid as long as the instruction is “alive”. Customers will be able to reuse this sender’s message reference only once the instruction is cancelled or settled (except if the same reference is used for different common code).

As per SWIFT ISO 15022, the sender’s message reference of a settlement instruction (MT540-543) is mentioned in field :20C::SEME of mandatory sequence A. As per industry guidelines, any sender’s message reference that is mentioned in the sender’s reference field (:20C::SEME) should be unique and cannot be used for multiple existing instructions.

From the effective date, any instruction that is sent by a customer to Clearstream Banking with a sender’s message reference that is not unique for a given common code will be rejected and the customer will be informed via SWIFT MT548 of the rejection.

At the cutover, if there are still some customers that have pending instructions with duplicate references for a given common code, they will automatically be switched to a special set-up for a transition period that should not last more than three months.

These customers will have the below restrictions:

  • No access to the new partial release functionality;
  • No access to the new cancellation/update method for partially settled instructions (it will be mandatory to mention the original quantity/amount in the cancellation/update).

Any customers that cannot foresee being ready by 22 November 2021, are encouraged to immediately contact their Client Service representative or Relationship Officer.

Further information

For further information, please contact Clearstream Banking Client Services or your Relationship Officer.


1. Clearstream Banking refers collectively to Clearstream Banking S.A., registered office at 42, avenue John F. Kennedy, L-1855 Luxembourg, and registered with the Luxembourg Trade and Companies Register under number B-9248, and Clearstream Banking AG, registered office at 61, Mergenthalerallee, 65760 Eschborn, Germany and registered in Register B of the Amtsgericht Frankfurt am Main, Germany under number HRB 7500.