What is the difference between MT544 and MT545?

The MT544 confirms a receipt free of payment (no cash moved); the MT545 confirms a receipt against payment and must carry the settled cash amount in 19A::ESTT.

The account servicer: the custodian, sub-custodian or CSD participant that holds the account. It goes to the account owner, or to a third party as a COPY.

Does an MT544 need a previous MT540?

Normally it answers an MT540 and quotes its SEME in 20C::RELA. When the receipt was not instructed by message, RELA carries NONREF.

Are corporate action receipts confirmed with MT544?

Usually not. Securities credited by a corporate action are reported in the MT566 corporate action confirmation.

What is the ISO 20022 equivalent of MT544?

sese.025 with movement type RECE and payment type FREE.

Category 5: Securities markets

MT544 Receive Free Confirmation

Written and maintained by ZagTrader. Last reviewed 21 October 2026. How this page is sourced and checked

The MT544 confirms that securities have been received into an account free of payment: no cash moved with them. The account servicer (custodian, sub-custodian or CSD participant) sends it to the account owner when the receipt has settled, normally in answer to the account owner’s MT540 Receive Free instruction.

Message type: MT544
Category: 5
Structure: 13 sequences, 64 fields listed
ISO 20022: sese.025, sese.024

When MT544 is used

Free of payment receipts are common outside plain trading: a portfolio moving in from another custodian (OWNE, PORT), a transfer between two accounts of the same owner (OWNI), securities borrowed (SECB) or collateral received (COLI), and trades whose cash settles separately. The account owner sends an MT540, the custodian instructs the market and reports progress in MT548, and the MT544 confirms the credit to the safekeeping account.

The link to the instruction is 20C::RELA, which carries the 20C::SEME of the MT540, often with :13A::LINK//540. If the receipt was not instructed by message, RELA is NONREF. Corporate action proceeds are normally reported in MT566, not in an MT544.

Partial settlement works as for the other confirmations: one MT544 per part, 22F::PARS//PAIN while part remains open and PARC on the last part, with 36B::ESTT giving the quantity of the current part.

If a confirmation was wrong (wrong account, wrong quantity, sent twice), the account servicer sends a new MT544 with 23G CANC and the old SEME in 20C::PREV, usually followed by a corrected NEWM. If the settlement itself is undone after it was confirmed, for example a contractual settlement that the market never completed or a booking the CSD unwound, it sends 23G RVSL with the same PREV link. After a reversal the instruction is open again and its status comes back in MT548. Reverse your own booking on RVSL; on CANC, wait for the replacement.

The four settlement confirmations share one layout and differ only in direction and payment: MT544 receive free, MT545 receive against payment, MT546 deliver free and MT547 deliver against payment. The against payment pair must carry the settled cash amount (19A::ESTT); for the free pair the amount sequence is optional. Receipts name the delivering agent (DEAG) as counterparty, deliveries the receiving agent (REAG).

MT544 format: sequences and fields

Sequence AGeneral InformationMandatory

Identifies the confirmation, says whether it is new, a cancellation or a reversal, and flags partial settlement or pre-confirmation.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	GENL	Opens the General Information block.
20C	SEME	Sender's Message Reference	M	:4!c//16x	The account servicer’s own reference for this confirmation. Each partial confirmation gets its own SEME. A later cancellation or reversal quotes it in 20C::PREV.
23G		Function of the Message	M	4!c[/4!c]	NEWM for a new confirmation, CANC to cancel a confirmation sent in error, RVSL to reverse a confirmation whose settlement has been undone. An optional subfunction marks a COPY for a third party, a DUPL (duplicate re-send) or CODU (copy of a duplicate).
98a	PREP	Preparation Date/Time	O	A: :4!c//8!n C: :4!c//8!n6!n E: :4!c//8!n6!n[,3n][/[N]2!n[2!n]]	When the account servicer produced the message. Useful to order messages that arrive close together.
22F	PARS	Partial Settlement Indicator	O	:4!c/[8c]/4!c	Present only when the confirmation covers part of the instruction. PAIN: part of the instruction is still open and more confirmations will follow. PARC: this is the last part and nothing more will settle.
22H	PREC	Pre-Confirmation Indicator	O	:4!c//4!c	Marks a pre-confirmation: PRCA when the cash movement is confirmed before the securities move, PRSE when the securities movement is confirmed before the cash. Mainly seen with against payment settlement.
16S		End of block	M	GENL	Closes the General Information block.

Sequence A1LinkagesMandatory, repeatable

At least one LINK block is required. Each block holds one 20C reference; the qualifier is a choice. RELA must appear in exactly one block. Only the commonly used qualifiers are listed.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	LINK	Opens the Linkages block.
13a	LINK	Linked Message	O	A: :4!c//3!c B: :4!c/[8c]/30x	The message type the reference belongs to, for example `:13A::LINK//540` next to the RELA of the MT540 instruction.
20C	RELA	Related Message Reference	M	:4!c//16x	The 20C::SEME of the account owner’s MT540 instruction. This is the key the receiver uses to close the open instruction. When there was no instruction message (for example an instruction received by fax or a movement generated by the account servicer), the value is NONREF.
20C	PREV	Previous Message Reference	C	:4!c//16x	The 20C::SEME of the earlier MT544 being cancelled or reversed. Required in exactly one LINK block when 23G is CANC or RVSL, not allowed otherwise.
20C	MITI	Market Infrastructure Transaction Identification	O	:4!c//16x	The reference given by the market infrastructure, for example the T2S actor reference or a CSD transaction number. Helps when you investigate with the CSD.
20C	PCTI	Processor Transaction Identification	O	:4!c//16x	Reference of a processor other than the account owner, the account servicer or the market infrastructure.
20C	COMM	Common Reference	O	:4!c//16x	The reference both trade counterparties agreed for the trade, when it was in the instruction.
20C	TRRF	Deal Reference	O	:4!c//16x	The deal reference assigned by the investment manager or broker, if the instruction carried one.
20C	POOL	Pool Reference	O	:4!c//16x	Groups several instructions that belong together, for example the pieces of a pooled or allocated trade.
16S		End of block	M	LINK	Closes the Linkages block.

Sequence BTrade DetailsMandatory

Dates, price and the security. 98a::ESET and 35B are the only mandatory items.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	TRADDET	Opens the Trade Details block.
94a	TRAD	Place of TradeRepeatable	O	B: :4!c/[8c]/4!c[/30x] L: :4!c//18!c2!n	Where the trade was executed: EXCH followed by the exchange’s MIC, or OTCO for over the counter.
98a	SETT	Settlement Date/Time	O	A: :4!c//8!n B: :4!c/[8c]/4!c C: :4!c//8!n6!n	The contractual (instructed) settlement date from the MT540. Compare it with ESET to see whether the trade settled late.
98a	TRAD	Trade Date/Time	O	A: :4!c//8!n B: :4!c/[8c]/4!c C: :4!c//8!n6!n E: :4!c//8!n6!n[,3n][/[N]2!n[2!n]]	The date the trade was executed.
98a	ESET	Effective Settlement Date/Time	M	A: :4!c//8!n B: :4!c/[8c]/4!c C: :4!c//8!n6!n	The date (and optionally the time) the movement actually settled. This is the booking date for the position. For a partial settlement it is the date of this part.
90a	DEAL	Deal Price	O	A: :4!c//4!c/[N]15d B: :4!c//4!c/3!a15d	The trade price: option A as a percentage or yield (PRCT, YIEL), option B as an amount per unit with a currency (ACTU).
99A	DAAC	Number of Days Accrued	O	:4!c//[N]3!n	Days of accrued interest, for interest-bearing securities.
35B		Identification of the Financial Instrument	M	[ISIN1!e12!c] [4*35x]	The security: `ISIN` followed by the 12-character ISIN, and optionally up to four lines of description.
70E	SPRO	Settlement Instruction Processing Narrative	O	:4!c//10*35x	Free text from the account servicer about how the instruction was processed.
16S		End of block	M	TRADDET	Closes the Trade Details block.

Sequence B1Financial Instrument AttributesOptional

Optional details of the security (type, currency of denomination, dates, rates). Rarely sent on confirmations; a few fields shown.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	FIA	Opens the Financial Instrument Attributes block.
11A	DENO	Currency of Denomination	O	:4!c//3!a	The currency in which the security is denominated.
98A	MATU	Maturity Date	O	:4!c//8!n	Maturity date of a debt instrument.
92A	INTR	Interest Rate	O	:4!c//[N]15d	Current interest rate of the security.
16S		End of block	M	FIA	Closes the Financial Instrument Attributes block.

Sequence CFinancial Instrument/AccountMandatory

What quantity settled, and on which safekeeping account.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	FIAC	Opens the Financial Instrument/Account block.
36B	ESTT	Quantity of Financial Instrument SettledRepeatable	M	:4!c//4!c/15d	The quantity that settled with this confirmation: UNIT for shares and units, FAMT for the face amount of debt. For a partial settlement it is the quantity of this part only. It may appear twice only to give FAMT together with AMOR (amortised value). Recent releases add option D (`:4!c//4!c/30d`) for digital token quantities.
36B	PSTT	Quantity Previously Settled	O	:4!c//4!c/15d	Partial settlement: quantity already confirmed by earlier confirmations for the same instruction.
36B	RSTT	Quantity Remaining to be Settled	O	:4!c//4!c/15d	Partial settlement: quantity still open after this part.
19A	PSTT	Previously Settled Amount	O	:4!c//[N]3!a15d	Partial settlement: cash amount already settled by earlier parts.
19A	RSTT	Remaining Settlement Amount	O	:4!c//[N]3!a15d	Partial settlement: cash amount still to settle.
95a	ACOW	Account Owner	O	P: :4!c//4!a2!a2!c[3!c] R: :4!c/8c/34x	The owner of the safekeeping account when it is not the receiver of the message, for example the fund behind a global custodian.
97a	SAFE	Safekeeping Account	M	A: :4!c//35x B: :4!c/[8c]/4!c/35x	The securities account credited. It should be the account given in the instruction. Recent releases allow a blockchain address or wallet (97D::BCAW) in its place.
97a	CASH	Cash Account	O	A: :4!c//35x E: :4!c//34x	A cash account linked to the movement, rarely used for free of payment settlement.
94a	SAFE	Place of SafekeepingRepeatable	O	B: :4!c/[8c]/4!c[/30x] C: :4!c//2!a F: :4!c//4!c/4!a2!a2!c[3!c] L: :4!c//18!c2!n	Where the securities are held, for example `:94F::SAFE//NCSD/CSDXAEADXXX` for a national CSD or ICSD for an international one.
16S		End of block	M	FIAC	Closes the Financial Instrument/Account block.

Sequence C1Quantity BreakdownOptional, repeatable

Lot or sub-balance details, used for tax lots in some markets.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	BREAK	Opens the Quantity Breakdown block.
13B	LOTS	Lot Number	O	:4!c/[8c]/30x	Identifier of the lot.
36B	LOTS	Quantity in the Lot	O	:4!c//4!c/15d	Quantity that belongs to the lot.
16S		End of block	M	BREAK	Closes the Quantity Breakdown block.

Sequence DTwo Leg Transaction DetailsOptional

Only for repos, sell/buy-backs and securities lending: details of the second leg. A few fields shown.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	REPO	Opens the Two Leg Transaction Details block.
98a	TERM	Closing Date/Time	O	A: :4!c//8!n B: :4!c/[8c]/4!c C: :4!c//8!n6!n	Date of the closing leg, or OPEN for an open-ended repo.
20C	SECO	Second Leg Reference	O	:4!c//16x	Reference of the closing-leg instruction.
92a	REPO	Repurchase Rate	O	A: :4!c//[N]15d	The repo rate agreed for the transaction.
19A	TRTE	Termination Transaction Amount	O	:4!c//[N]3!a15d	Amount to be paid on the closing leg.
16S		End of block	M	REPO	Closes the Two Leg Transaction Details block.

Sequence ESettlement DetailsMandatory

The transaction type, the settlement chain and the amounts. Only the commonly used 22F indicators are listed.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	SETDET	Opens the Settlement Details block.
22F	SETR	Type of Settlement Transaction Indicator	M	:4!c/[8c]/4!c	What kind of transaction settled, normally copied from the instruction: TRAD for a trade, OWNE or OWNI for account transfers, SECL or SECB for lending and borrowing, REPU for a repo, COLI or COLO for collateral.
22F	STCO	Settlement Transaction Condition IndicatorRepeatable	O	:4!c/[8c]/4!c	Conditions copied from the instruction, for example NPAR (no partial settlement allowed) or PART (partial settlement allowed).
22F	RTGS	Securities RTGS Indicator	O	:4!c/[8c]/4!c	YRTG or NRTG: whether the settlement went through the real-time gross settlement channel of the CSD.
22F	DBNM	Settlement Standing Instruction Database Indicator	O	:4!c/[8c]/4!c	Says the settlement chain comes from a standing settlement instruction database. When it is absent, the delivering agent and the place of settlement must be given in E1.
16S		End of block	M	SETDET	Closes the Settlement Details block.

Sequence E1Settlement PartiesMandatory, repeatable

One block per party in the chain. Each party qualifier may appear only once in the message. Only the commonly used qualifiers are listed.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	SETPRTY	Opens the Settlement Parties block.
95a	PSET	Place of Settlement	C	C: :4!c//2!a P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x	The CSD or ICSD where settlement took place, for example `:95P::PSET//CSDXAEADXXX`. Required unless 22F::DBNM is present. A block with PSET cannot also carry 97a::SAFE.
95a	DEAG	Delivering Agent	C	P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x R: :4!c/8c/34x	The CSD participant that delivered the securities: the party that delivered the securities to you, at the place of settlement. Required unless 22F::DBNM is present.
95a	SELL	Seller	O	P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x R: :4!c/8c/34x	The deliverer’s client, when it differs from the delivering agent.
95a	DECU	Deliverer's Custodian	O	P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x R: :4!c/8c/34x	Custodian of the seller, between the seller and the delivering agent. If present, SELL must be present too.
95a	REAG	Receiving Agent	O	P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x R: :4!c/8c/34x	Your own side: the participant that received the securities, usually the account servicer or its sub-custodian.
97a	SAFE	Safekeeping Account	C	A: :4!c//35x B: :4!c/[8c]/4!c/35x	The account of the party in this block at its own servicer. Not allowed in the PSET block.
20C	PROC	Processing Reference	O	:4!c//16x	A reference that this party gave the transaction, for example the CSD participant’s reference.
16S		End of block	M	SETPRTY	Closes the Settlement Parties block.

Sequence E2Cash PartiesOptional, repeatable

Rarely used on free of payment confirmations.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	CSHPRTY	Opens the Cash Parties block.
95a	PAYE	Paying Institution	O	P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x R: :4!c/8c/34x	The institution that paid the money for you.
97a	CASH	Cash Account	O	A: :4!c//35x E: :4!c//34x	Account of the cash party.
16S		End of block	M	CSHPRTY	Closes the Cash Parties block.

Sequence E3AmountOptional, repeatable

Optional for free of payment. One block per amount; no amount qualifier may appear in more than one block.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	AMT	Opens the Amount block.
17B	ACRU	Accrued Interest Flag	O	:4!c//1!a	Y or N: whether accrued interest is included in the settled amount.
19A	ESTT	Settled Amount	O	:4!c//[N]3!a15d	An amount that settled with the movement. Normally absent on a free of payment confirmation.
19A	DEAL	Trade Amount	O	:4!c//[N]3!a15d	Quantity times price, before charges and accrued interest.
19A	ACRU	Accrued Interest Amount	O	:4!c//[N]3!a15d	Accrued interest included in the settlement, for bonds.
19A	CHAR	Charges/Fees	O	:4!c//[N]3!a15d	Charges taken on the settlement.
98a	VALU	Value Date/Time	C	A: :4!c//8!n C: :4!c//8!n6!n	Value date of the cash. Allowed only in the block that carries 19A::ESTT.
92B	EXCH	Exchange Rate	O	:4!c//3!a/3!a/15d	Rate used when the amount was converted. If present, 19A::RESU (resulting amount) must be in the same block.
16S		End of block	M	AMT	Closes the Amount block.

Sequence E4Digital Network FeeOptional

Added in recent standards releases for securities that settle on a distributed ledger: the fee paid to the network, in digital tokens.

Tag	Name	Status	Format	Meaning
16R	Start of block	M	NTWKFEE	Opens the Digital Network Fee block.
35B	Identification of the Financial Instrument	M	[ISIN1!e12!c] [4*35x]	The digital token in which the network fee was paid.
36D	Quantity of Financial Instrument	M	:4!c//4!c/30d	The quantity of digital tokens paid as the network fee.
16S	End of block	M	NTWKFEE	Closes the Digital Network Fee block.

Sequence FOther PartiesOptional, repeatable

Parties outside the settlement chain. A few qualifiers shown.

Tag	Qualifier	Name	Status	Format	Meaning
16R		Start of block	M	OTHRPRTY	Opens the Other Parties block.
95a	INVE	Investor	O	C: :4!c//2!a P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x R: :4!c/8c/34x	The investor, when the market requires it to be identified.
95a	BRKR	Broker	O	P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x R: :4!c/8c/34x	The broker of the trade.
95a	MEOR	Originator of Message	O	P: :4!c//4!a2!a2!c[3!c] Q: :4!c//4*35x R: :4!c/8c/34x	The party that originated the message, when sent through a service bureau or a central platform.
16S		End of block	M	OTHRPRTY	Closes the Other Parties block.

Format notation: n digits, a upper-case letters, c upper-case letters and digits, x any character of the Swift character set, d a decimal number with a comma, ! fixed length, [ ] optional, 4*35x up to 4 lines of 35 characters. M mandatory, O optional, C conditional (a rule decides).

Rules worth knowing

Sequence A1 is mandatory, and 20C::RELA must be present in exactly one LINK block (error code C73). Use NONREF when the movement was not instructed by message.
If 23G is CANC or RVSL, 20C::PREV must be present in exactly one LINK block, carrying the SEME of the confirmation being cancelled or reversed; with NEWM it is not used (error code E08).
36B::ESTT may appear at most twice in sequence C, and then one occurrence must use FAMT and the other AMOR (error code C71).
Unless 22F::DBNM is present in sequence E, one E1 block must carry 95a::DEAG and another 95a::PSET (error code E91). A block with 95a::PSET must not carry 97a::SAFE (error code E52).
A party qualifier may appear only once in the message (error code E84), and each side of the chain must be complete: DEI2 needs DEI1, DEI1 needs DECU, DECU needs SELL; REI2 needs REI1, REI1 needs RECU, RECU needs BUYR (error code E86).
Sequence E3 is optional. When amounts are given, each amount qualifier may appear in only one E3 block, and 92B::EXCH needs 19A::RESU in the same block.
Market practice for partial settlement (SMPG): 22F::PARS//PAIN on every partial confirmation except the last, PARC on the last one. 36B::ESTT always gives the quantity of the current part; PSTT and RSTT are optional.
A cancellation (CANC) repeats at least the mandatory fields of the confirmation it cancels.

MT544 example

ZAGTAEADXXX moved a holding of 25,000 units from another custodian (BANKAEADXXX) to CUSTAEADXXX and instructed the receipt with an MT540 referenced ZT2610190042. The custodian confirms the free receipt at the local CSD on 22 October 2026.

{1:F01CUSTAEADAXXX0000000000}{2:I544ZAGTAEADXXXXN}{4:
:16R:GENL
:20C::SEME//CA544-0000977
:23G:NEWM
:98C::PREP//20261022101500
:16R:LINK
:13A::LINK//540
:20C::RELA//ZT2610190042
:16S:LINK
:16S:GENL
:16R:TRADDET
:98A::SETT//20261022
:98A::ESET//20261022
:35B:ISIN AEZAGT000024
ZAGTRADER TEST REIT
:16S:TRADDET
:16R:FIAC
:36B::ESTT//UNIT/25000,
:97A::SAFE//ZAG-SAFE-0002
:16S:FIAC
:16R:SETDET
:22F::SETR//OWNE
:16R:SETPRTY
:95P::DEAG//BANKAEADXXX
:16S:SETPRTY
:16R:SETPRTY
:95P::PSET//CSDXAEADXXX
:16S:SETPRTY
:16S:SETDET
-}

Decode this example in the parser

Line by line

Line	What it says
{1:F01CUSTAEADAXXX0000000000}{2:I544ZAGTAEADXXXXN}{4:	Basic header: sender CUSTAEADXXX (the account servicer). Application header: input MT544 to ZAGTAEADXXX (the account owner), normal priority.
:16R:GENL
:20C::SEME//CA544-0000977	The custodian’s reference for this confirmation.
:23G:NEWM	A new confirmation.
:98C::PREP//20261022101500
:16R:LINK
:13A::LINK//540	The linked message is an MT540.
:20C::RELA//ZT2610190042	The account owner’s reference from the MT540.
:16S:LINK
:16S:GENL
:16R:TRADDET
:98A::SETT//20261022	Instructed settlement date.
:98A::ESET//20261022	Effective settlement date.
:35B:ISIN AEZAGT000024	The security (test ISIN).
ZAGTRADER TEST REIT
:16S:TRADDET
:16R:FIAC
:36B::ESTT//UNIT/25000,	Quantity received.
:97A::SAFE//ZAG-SAFE-0002	Safekeeping account credited.
:16S:FIAC
:16R:SETDET
:22F::SETR//OWNE	External account transfer: the holding moved between account servicers.
:16R:SETPRTY
:95P::DEAG//BANKAEADXXX	Delivering agent: the previous custodian.
:16S:SETPRTY
:16R:SETPRTY
:95P::PSET//CSDXAEADXXX	Place of settlement.
:16S:SETPRTY
:16S:SETDET	No amount sequence: nothing was paid.
-}	End of block 4.

All BICs, references, accounts and the ISIN are made up; the ISIN has a valid check digit.

Common errors and rejects

Receipt confirmed on a different account than instructed
Compare 97a::SAFE with the account in your MT540. A difference usually means the custodian booked to a default account; ask for a CANC and a corrected NEWM rather than moving the position yourself.
Confirmation does not match an open instruction
RELA is NONREF or an unknown reference, typical for transfers the custodian received without your instruction. Match on ISIN, quantity and delivering agent, then ask the custodian whether a MT540 was expected.
Transfer in only partly received
Look for 22F::PARS//PAIN and 36B::RSTT. Portfolio moves often settle line by line and in parts; keep the remainder open until PARC arrives.
Expected receipt never confirmed
Check the MT548 for the instruction. An unmatched status (NMAT, often CMIS) means the delivering custodian has not instructed yet or used different details.
How to fix it
Confirmation reversed after booking (23G RVSL)
The receipt was taken back. Reverse your booking and follow the new MT548 statuses until a fresh MT544 arrives.

MT544 in ISO 20022

The ISO 20022 equivalent is sese.025 Securities Settlement Transaction Confirmation with TxIdDtls/SctiesMvmntTp = RECE and TxIdDtls/Pmt = FREE. The RELA reference becomes TxIdDtls/AcctOwnrTxId and 98A::ESET becomes TradDtls/FctvSttlmDt. Reversals use the separate sese.026 message; statuses before settlement use sese.024.

Securities messages were not part of the November 2025 payments deadline: the MT544 stays in use on FIN, while T2S and its directly connected participants use sese.025.

MT544 questions

What is the difference between MT544 and MT545?: The MT544 confirms a receipt free of payment (no cash moved); the MT545 confirms a receipt against payment and must carry the settled cash amount in 19A::ESTT.
Who sends the MT544?: The account servicer: the custodian, sub-custodian or CSD participant that holds the account. It goes to the account owner, or to a third party as a COPY.
Does an MT544 need a previous MT540?: Normally it answers an MT540 and quotes its SEME in 20C::RELA. When the receipt was not instructed by message, RELA carries NONREF.
Are corporate action receipts confirmed with MT544?: Usually not. Securities credited by a corporate action are reported in the MT566 corporate action confirmation.
What is the ISO 20022 equivalent of MT544?: sese.025 with movement type RECE and payment type FREE.

The trading side of the trade: FIX

Before a settlement instruction is sent, the trade is usually executed, allocated and confirmed over FIX, and the instruction must copy what was agreed there. Read those messages on the free ZagTrader FIX Parser:

From FIX execution to settlement: which FIX field becomes which settlement field, and where breaks start
Allocation Instruction (35=J): how a block trade is split across accounts
Confirmation (35=AK): the confirmed economics per allocation
Settlement Instructions (35=T): standing settlement instructions over FIX

All MT messages · Category 5 messages · ISO 20022 messages · Codes · Troubleshooting