sese.026 — Securities Settlement Transaction Reversal Advice

The reversal advice for a settled transaction. When a closed settlement must be undone — counterparty default, calculation error, post-trade arbitration ruling — the CSD issues this message to restore positions to their pre-settlement state.

Purpose and place in the flow

sese.026 is the reversal advice for a previously settled securities-settlement transaction. Three scenario families trigger a reversal:

• Post-trade counterparty default — the counterparty defaults between settlement and end of the guarantee window: the CSD or CCP (if interposed) backs out the transaction and restores positions.
• Operational error discovered late — wrong entry, wrong quantity, wrong counterparty: if discovered within the reversibility window (typically T+1 to T+3), the CSD can rewind.
• Arbitration or regulator decision — a court, regulator or dispute resolution panel mandates the rollback of a transaction (rare but notable — see GameStop short squeeze 2021).

sese.026 is the exact inverse of sese.025 (settlement confirmation): it restores cash and securities positions, and triggers mirror accounting entries (cancellation of commissions, taxes, accrued interest in between).

XML structure

• TxId — identifier of the original transaction (from sese.023 then sese.025).
• SttlmTpAndAddtlParams — movement and payment type (carried over).
• RvslRsn — Reversal Reason: reason code (SETR settlement reversal, CPTY counterparty default, REGL regulator decision…).
• TradDt / SttlmDt / RvslDt — trade date, original settlement date, reversal date.
• FinInstrmId — ISIN.
• QtyAndAcctDtls — reversed quantity + concerned account.
• SttlmAmt — reversed cash amount with reverse direction (DBIT if original sese.025 was CRDT, and vice-versa).

Key fields

• TxId — identifier of the reversed transaction, identical to original sese.025.
• RvslRsn/Cd — reason code (SETR, CPTY, REGL, CORR = correction).
• RvslDt/Dt/Dt — effective date of the reversal.
• SttlmAmt/CdtDbtInd — inverted vs the original sese.025.
• AddtlInf/Inf — in practice mandatory narrative explaining the context (for audit purposes).

XML example

DTCC reverses a sese.025 transaction settled on 15 May (1,000 Apple shares delivered by BNP, against 175,250 USD received). On 16 May, the counterparty Goldman Sachs Custody defaults on its ancillary obligations; DTCC rolls back the transaction:

<?xml version="1.0" encoding="UTF-8"?>
<Document xmlns="urn:iso:std:iso:20022:tech:xsd:sese.026.001.10">
  <SctiesSttlmTxRvslAdvc>
    <TxId>BNPP-SETT-20260514-001</TxId>
    <SttlmTpAndAddtlParams>
      <SctiesMvmntTp>DELI</SctiesMvmntTp>
      <Pmt>APMT</Pmt>
    </SttlmTpAndAddtlParams>
    <RvslRsn>
      <Cd>SETR</Cd>
    </RvslRsn>
    <TradDt>
      <Dt>
        <Dt>2026-05-14</Dt>
      </Dt>
    </TradDt>
    <SttlmDt>
      <Dt>
        <Dt>2026-05-15</Dt>
      </Dt>
    </SttlmDt>
    <RvslDt>
      <Dt>
        <Dt>2026-05-16</Dt>
      </Dt>
    </RvslDt>
    <FinInstrmId>
      <ISIN>US0378331005</ISIN>
    </FinInstrmId>
    <QtyAndAcctDtls>
      <SttlmQty>
        <Qty>
          <Unit>1000</Unit>
        </Qty>
      </SttlmQty>
      <SfkpgAcct>
        <Id>BNPPSAFEKEEP-NYSE-001</Id>
      </SfkpgAcct>
    </QtyAndAcctDtls>
    <SttlmAmt>
      <Amt Ccy="USD">175250.00</Amt>
      <CdtDbtInd>DBIT</CdtDbtInd>
    </SttlmAmt>
    <AddtlInf>
      <Inf>REVERSAL DUE TO COUNTERPARTY DEFAULT — TRADE BACKED OUT BY DTCC POST-SETTLEMENT</Inf>
    </AddtlInf>
  </SctiesSttlmTxRvslAdvc>
</Document>

Consequences: BNP recovers its 1,000 Apple shares in account, and returns the 175,250 USD (DBIT direction). All commissions, US taxes (SEC fee, section 31), CSD fees must be readjusted via separate accounting entries.

Common pitfalls

• Modified TxId — the TxId must be strictly identical to the original sese.025. A discrepancy prevents custodian matching and breaks the audit trail.
• Non-inverted CdtDbtInd — if the sese.025 carried CRDT, the sese.026 must carry DBIT (and vice-versa). Keeping the original direction causes a double credit / debit on the ledger.
• Forgotten commissions — sese.026 reverses the main transaction, not commissions or taxes paid separately. Plan downstream adjustments via camt.054 or internal entries.
• Window exceeded — beyond the CSD SLA (typically T+3 in the US, T+2 in Europe), the CSD refuses the reversal. Always check current date < SttlmDt + window.
• No narrative — AddtlInf is technically optional but in practice required by compliance for audit trail. Always document the detailed reason.

Related messages

• sese.023 — Securities Settlement Transaction Instruction, the original instruction.
• sese.024 — Securities Settlement Status Advice.
• sese.025 — Securities Settlement Transaction Confirmation (the message to be reversed).
• sese.028 — Settlement Conditions Modification Status Advice.
• SWIFT MT: no direct equivalent; an MT548 (statement of pending transactions) can flag the reversal.