Representing CARN (Client Allocation Reference Number) in Allocation Report

1

Hi Team,

The Client Allocation Reference Number(CARN) is used within DTCC’s Central Trade Manager (CTM) to track and manage trade allocations. It helps ensure accurate settlement and reconciliation between counterparties.

The CARN is a 16 character field.

Is there any way by which this can be represented in the FIXML Allocation Report? Please let me know.

Regards,
Rahul

2

@rahulmohanraj does the CARN refer to the individual allocation or to the block level? FIX has two fields SecondaryAllocID (793) and SecondaryIndividualAllocID(989) that may be used as an additional allocation identifier. More information is needed, is there a public link to a DTCC document that describes the CARN?

Please elaborate on who issues the CARN (DTCC or client) and how the CARN is used within the allocation workflow (instruction → instructionack → report → reportack).

3

Thanks for the reply and apologies for the delay. I was trying to get the details you requested.

Please find the below

  • CARN is at the individual allocation level

  • For relevant documentation from DTCC, please use this link - M2i and look for the document CTM MATCH TO INSTRUCT (M2I) WORKFLOW: IMPLEMENTATION GUIDE FOR EXECUTING BROKERS Please read about CTM Client Allocation Reference in page 32. It says it is unique and has a maximum length of 16.

  • Client applications issues CARN and is required in the Allocation Report.

4

Alternatively option is tag 467, IndividualAllocID.

5

@rahulmohanraj thanks for the DTCC documentation reference. However, it requires a login and does not seem to be intended for the general public. But you clarified that it is about the individual allocation and not at the block level.

6

@rahulmohanraj If the CARN is an reference number assigned by the client/buy-side for a given instance (e.g. account level) of an allocation instruction, the value for this should be in the AllocationInstruction(35=J) should be within the IndividualAllocID(467). Note that in FIX there is no limitation on length for ID fields so it would be up to the client/buy-side to assign a value that is 16-char in order for the value to be usable in CTM.

You mentioned AllocationReport(35=AS) this is a message that is typically sent by the broker back to the buy-side, or from a system like CTM back to the client that submitted the AllocationInstruction into CTM. If the CARN is an ID assigned by CTM for each allocation instance that is conveyed back to the client, then I would sugges that CTM uses SecondaryIndividualAllocID(989) so that the IndividualAllocID(467) can echo back the client’s value.

In your second reply you quoted CTM text, which say “client applications issues CARN and is required in the AllocationReport” I find it puzzling that CTM is asking the executing broker to send AllocationReport(35=AS) to CTM.