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Spotlight PEPPOL BIS Billing 3.0 The EU e-invoicing mandate is here — France Sept 2026, Belgium Jan 2026, Germany 2025.

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Tools

MT500 — Instruction to Register

The instruction to record a registered security on the transfer agent's register. On markets where dematerialisation relies on a central register (US, UK, Canada, Hong Kong…), this is the pivot message of the transition from street name to registered owner.

Purpose

MT500 asks the transfer agent (TA) — DTCC for US equities, Computershare, Equiniti, EQ Holdings, Link Group… — to inscribe a new owner on the security's register. The target can be:

  • The move from a street-name holding (held through a custodian under the nominee name) to a direct registration under the ultimate holder's name (registered holder).
  • The inscription of a new security acquired by a retail investor that requires the registered form (US Direct Registration System — DRS, or Direct Holding in the UK).
  • The conversion between bearer and registered form for securities that allow both (rare in 2026 outside the bond market).

MT500 is the notice of intent: the effective registration is confirmed by MT501. On regulated markets, the delay between the two is typically 2 to 5 business days (KYC due diligence on the registered holder).

Sequence structure

MT500 uses the :16R: / :16S: sequences typical of Cat 5:

  • GENL — General Information: reference (SEME), function (NEWM, CANC, AMEN), preparation date.
  • REGDET — Registration Details: security, quantity to register, designated transfer agent, registered holder identity (sub-sequence REGDTL).
  • SETDET — Settlement Details: settlement type (typically REGT — Registration Only — with no cash leg).

Block 4 tags

TagNameFormatUsage
:16R: / :16S:Start of Block / End of Block4!cDelimits GENL, REGDET, REGDTL, SETDET.
:20C:Reference:4!c//16xSEME (sender's message reference), PREV.
:23G:Function of the Message4!c[/4!c]NEWM (new instruction), CANC (cancel), AMEN (amend).
:98A:Date:4!c//8!nPREP, REGI (target registration date).
:35B:Identification of the Instrument4*35xISIN + trade name.
:36B:Quantity:4!c//4!c/15dREGI (quantity to register), UNIT for equities, FAMT for bonds.
:97A:Account Identification:4!c//35xSAFE (safekeeping account), source securities account.
:95P:Party Identification:4!c//4!a2!a2!c[3!c]REGI (registrar), BIC of the transfer agent.
:95Q:Party Identification (Name & Address):4!c//4*35xBENM (beneficiary), full identity of the registered holder.
:22F:Indicator:4!c[/8c]/4!cSETR (settlement transaction type), value REGT for Registration Only.

Real-world example

Instruction to register 5,000 IBM shares (ISIN US4592001014) under the name of the John Smith Family Trust, sent by BNP Paribas (custodian) to Citi (DTC-eligible registrar) on 16 May 2026:

text mt500-register.txt 
{1:F01BNPAFRPPAXXX0000000000}{2:I500CITIUS33XXXXN}{3:{108:REG20260516001}}{4:
:16R:GENL
:20C::SEME//REG20260516001
:23G:NEWM
:98A::PREP//20260516
:16S:GENL
:16R:REGDET
:98A::REGI//20260516
:35B:ISIN US4592001014
IBM CORP
:36B::REGI//UNIT/5000,
:97A::SAFE//IBMHOLDREG-001
:95P::REGI//CITIUS33XXX
:16R:REGDTL
:95Q::BENM
JOHN SMITH FAMILY TRUST
123 MAIN ST
NEW YORK NY 10001
:16S:REGDTL
:16S:REGDET
:16R:SETDET
:22F::SETR//REGT
:16S:SETDET}
  • :23G:NEWM — new registration instruction.
  • :35B:ISIN US4592001014 — IBM Corp shares.
  • :36B::REGI//UNIT/5000, — 5,000 units to register.
  • :97A::SAFE//IBMHOLDREG-001 — source safekeeping account at the custodian.
  • :95P::REGI//CITIUS33XXX — BIC of the destination transfer agent (Citi).
  • :95Q::BENM — ultimate beneficiary (John Smith Family Trust).
  • :22F::SETR//REGT — Registration Only settlement type (no cash leg).

Common pitfalls

  • Incomplete beneficiary — :95Q::BENM must carry at least the full legal name and a verifiable address. The transfer agent rejects truncated BENM for KYC reasons.
  • Non DRS-eligible ISIN — in the US, not every security is eligible for the Direct Registration System. An MT500 for a non-DRS-eligible security is rejected by the registrar.
  • Fractional quantity — registered nominee inscription on listed shares requires integer units. Fractions generated by corporate actions (stock dividend, split) must be cash-settled, not registered.
  • Confusion REGI / SAFE — :97A::SAFE// is the SOURCE account at the custodian; the DESTINATION account (registered owner account) is implicit on the registrar side, created from :95Q::BENM.
  • Wrong SETR — for an ownership transfer with no cash, use SETR=REGT rather than TRAD. Otherwise the registrar waits for a cash leg that will never arrive.

ISO 20022 equivalent

There is no strictly isomorphic ISO 20022 equivalent of MT500. The registration function is carried by:

  • reda.001 — Reference Data Reporting: for register updates on the issuer/registrar side.
  • sese.023 / sese.024 — Securities Settlement Instruction/Status: for the securities movement with SttlmParams/SctiesTxTp=REGT.
  • Most transfer agents still process MT500/MT501 natively, without a mandatory ISO 20022 equivalent.
  • MT501 — Confirmation of Registration or Modification, the transfer agent's reply.
  • MT535 — Statement of Holdings, statement that will reflect the security as registered after confirmation.
  • MT564 — Corporate Action Notification, triggered if the registration occurs during a corporate action.
  • ISO 20022: reda.008, sese.023.