sese.031 — Securities Settlement Conditions Modification Request

The request to modify the conditions of a non-settled securities settlement instruction: matching priority, partial settlement allowed, hold/release. The operational lever to intervene mid-cycle on T2S and Euroclear.

Purpose and place in the flow

sese.031 lets the participant modify the operational conditions of a settlement instruction already submitted but not yet settled: allow or disallow a partial settlement, place in hold (temporarily suspend), release (after hold), change matching priority, adjust the settlement date (intra-cycle).

Typical use: a trader sees that the counterparty does not have enough securities to settle the 10,000 shares at the next window; to avoid failing the full settlement, it sends sese.031 with PrtlSttlmInd=PART to allow a partial settlement (for example 5,000 available shares are settled immediately, the remaining 5,000 wait for the next cycle).

XML structure

sese.031 is wrapped in <Document> then the root <SctiesSttlmCondsModReq>. Structure:

• ModReqRef — Unique modification request identifier.
• AcctOwnr (Account Owner) — Participant identification (BIC).
• SfkpgAcct (Safekeeping Account) — Affected securities account.
• ReqDtls — Main block: transaction reference + requested modifications.
• TxId — Reference of the instruction to modify.
• ReqdMod (Requested Modification) — Which condition to change.

Key fields

• ModReqRef/Id — Unique request identifier (max 35 chars).
• AcctOwnr/Id/AnyBIC/AnyBIC — Participant BIC.
• SfkpgAcct/Id — CSD securities account identifier (max 35 chars).
• ReqDtls/TxId/AcctOwnrTxId — Original instruction reference (= :20: of the sese.023).
• ReqdMod/PrtlSttlmInd — Partial settlement indicator: PART (allow), NPAR (disallow), PARC (allow with minimum quantity).
• ReqdMod/HldInd — Hold/Release: HOLD (suspend), RELS (release).
• ReqdMod/Prty/Nmrc/Prty — Numeric priority 0-9 (0 = highest).
• ReqdMod/SttlmDt — New settlement date.

XML example

Request sent by BNP Paribas (custodian) to T2S on 16 May 2026 to disallow partial settlement (NPAR) on transaction ACME-DVP-2026-187, securities account 5101000ACME:

<?xml version="1.0" encoding="UTF-8"?>
<Document xmlns="urn:iso:std:iso:20022:tech:xsd:sese.031.001.10">
  <SctiesSttlmCondsModReq>
    <ModReqRef>
      <Id>ACME-MOD-20260516-001</Id>
    </ModReqRef>
    <AcctOwnr>
      <Id>
        <AnyBIC>
          <AnyBIC>BNPAFRPP</AnyBIC>
        </AnyBIC>
      </Id>
    </AcctOwnr>
    <SfkpgAcct>
      <Id>5101000ACME</Id>
    </SfkpgAcct>
    <ReqDtls>
      <TxId>
        <AcctOwnrTxId>ACME-DVP-2026-187</AcctOwnrTxId>
      </TxId>
      <ReqdMod>
        <PrtlSttlmInd>NPAR</PrtlSttlmInd>
      </ReqdMod>
    </ReqDtls>
  </SctiesSttlmCondsModReq>
</Document>

Versions

Common pitfalls

• Modification after settlement — a sese.031 sent after the instruction is settled is rejected (sese.032 «TOO LATE»). Send as soon as you spot the need.
• HOLD vs CANCEL confusion — HOLD pauses temporarily (can be released later). CANCEL cancels definitively (use sese.020). Confusing the two can lose the instruction.
• Missing or wrong SfkpgAcct — for T2S, the securities account is a strict identifier (CSD proprietary format). Check the T2S membership contract.
• Ignored priority — the numeric priority 0-9 tells the CSD the processing order among competing instructions. Setting every instruction to priority 0 cancels the effect.
• PrtlSttlmInd change without counterparty agreement — for a bilateral DvP (Delivery vs Payment), both counterparties must match on PrtlSttlmInd. Changing unilaterally can break the match.
• Invalid new SttlmDt — the new date cannot be before today nor beyond the CSDR limit (15 business days). Otherwise rejection.

Related messages

• sese.023 — Securities Settlement Transaction Instruction (original instruction).
• sese.024 — Status Advice.
• sese.025 — Settlement Confirmation.
• sese.032 — Modification Status Advice (reply to sese.031).
• sese.020 — Settlement Transaction Cancellation Request (full cancellation).