Swift
Swift
Swift
by virtue of involvement in
the design and implementation of S.W.I.F.T. integration solutions for major banking, broking
and fund management firms. We have worked on over 100 S.W.I.F.T. related projects in 22
countries and had experience of integrating with most of the common interfaces. Having
worked closely with both end-users and IT strategists to define the most effective way of
linking disparate back-office environments into the S.W.I.F.T. network, we are well qualified
to assist and advise not just on S.W.I.F.T., but on any similar requirement involving
integration with external networks. The rest of this page gives a short description of the
network itself, describes the message structures, some history and acronym context, and
If you're reading this to understand the background to S.W.I.F.T FIN message formats to
write your own message parsers, then we invite you to read our White Paper on "Just how
hard can it be to write your own SWIFT parser?" You should be able to knock one up in a
What is S.W.I.F.T.?
The acronym stands for Society for Worldwide Interbank Financial Telecommunications.
"The object of the Company is for the collective benefit of the Members of the Company, the
study, creation, utilisation and operation of the means necessary for the telecommunication,
The Society's headquarters are situated in La Hulpe, on the outskirts of Brussels. S.W.I.F.T.
also acts as a United Nations sanctioned International Standards Body (ISO) for the creation
S.W.I.F.T. was formed when seven Major International Banks met in 1974 to discuss the
primarily in the Treasury and Correspondent banking areas. Telex suffered from a number of
limitations due to its speed (50 Baud or approximately 8 bytes per second), its free format
(that made automation at the receiving end almost impossible), and the lack of security,
banks in 5 countries went live. New countries and users were and indeed still are, added 4
times a year with recent figures showing over 184 countries and 6700 institutions
connected.
Over the years message type coverage has been greatly expanded to cover a much greater
range of financial transactions, and new message types are added to the system once a
year between September and November. The original network was superseded by an X.25
based network in 1990 to cope with the increasing message volumes which now stand at
around 3,000,000 per day. Uniquely, S.W.I.F.T. take full liability for each message once they
have accepted it, and it is probably this linked to the inbuilt security and robustness of the
network (consistently better than 99.99% up time every year) that has led to S.W.I.F.T.'s
Although originally the network was designed to support the requirements of Treasury and
Correspondent banking operations, it has over the years allowed other institutions access to
the services, albeit in some cases only to a limited degree. Currently the following
• Banks
• Trading Institutions
• Money Brokers
• Securities Broker Dealers
• Investment Management Institutions
• Clearing Systems and Central Depositories
• Recognised Exchanges
• Trust and Fiduciary Service Companies
• Subsidiary Providers of Custody and Nominees
• Treasury Counterparties
• Treasury ETC Service Providers
The Society is owned by its Members, and in order to become one the organisation must
hold a Banking Licence. In return Members own shares in the society and have voting rights.
There are a further two classes of user. Sub - members must be >90% owned by member
and are typically branches. Whilst they have full access to the system they do not have
voting rights or shares. Participants are usually other types of financial institution, and they
All classes of member pay an initial joining fee and an annual support charge, although the
In addition users are charged on a per message basis by Unit lengths of 325 or 1950
characters dependant on message type. The charges also vary depending on Volume tier
and Route with the amounts reducing for high volume users and those messages passing
The pricing is calculated to cover all of S.W.I.F.T.'s costs and investments with users then
S.W.I.F.T. services
GPA General Purpose Application, which only allows system messages, i.e.. messages from a
user to S.W.I.F.T. and vice versa, not from one user to another
FIN Financial Application, which is the user to user service comprising, System Messages
MT0nn, User to User Messages MT1nn through 9nn and Service Messages such as
Acknowledgements
Additionally, S.W.I.F.T. provide a number of services that are charged for over and above the
IFT (Interbank File For bulk file transfer of messages, for example low net value, high volume
Transfer) Retail payments
ACCORD A centralised confirmation matching bureau service
Directory Services An automated and centralised Standard Settlement Instruction service for
message enrichment that at present is limited to Treasury and Payment
information
RTGS (Y-copy) Mostly used for sending a copy of a message or parts thereof to a third party,
for example a Central Bank
Country Specific (e.g. Where S.W.I.F.T.are either the carrier of the messages or the supplier of
CREST, CHAPSEuro) additional network services
There are a number of components to this X.25 protocol based packet switched network.
The System Control Processors are responsible for the operation of the entire system. This
includes:
• Session Management
• Software and database distribution
• Monitoring all S.W.I.F.T. hardware and software
• Failure diagnostics and recovery
• Dynamic allocation of system resources.
These are located at Operating Centres, 2 in the US centre and 2 at the centre in the
Netherlands.
All messages are safestored on two media. The SP's are located in the operating centres.
The Regional Processors are the entry and exit point to S.W.I.F.T. and they support Leased
line, Dial up or Public Data Network connection. The most common method is primary
leased line with dial-up backup. They are usually in same country as the user and provide
located at each user site. These terminals support the connectivity to the local regional
processor and facilitate both manual entry of messages and the bridge to originating
applications. Some more detail on the latter facility will be covered later. There are many
vendors of these interface devices although S.W.I.F.T. themselves have by far the largest
market share. The following is a list of some of the more common ones. A full list can be
provided by S.W.I.F.T.:
Vendors CBT
S.W.I.F.T. Alliance Access (NT and Unix)
S.W.I.F.T. Alliance Entry (NT)
S.W.I.F.T. ST400 (VMS)
IBM Merva/ESA (Mainframe)
IBM(S.W.I.F.T.) Merva/2 (OS/2)
IBM(S.W.I.F.T.) Merva/AIX (AIX)
Logica Fastwire (Unix)
Logica Bess (Tandem)
Mint Mint
Netik TurboSWIFT (NT and Unix)
access secure functions. Many functions require dual user and password input.
Initially a User will LOGIN to the GPA service and receive a GPA Acknowledgement. The User
then SELECTS the application or service that they wish to use, for example FIN. The user can
then send FIN messages to other users and the Regional Processor will either send back a
Positive (ACK) or Negative (NAK) acknowlegement for each message after having safestored
it.
The session then remains open for sending and receiving messages until the User QUITS.
The Fin service will acknowledge this before the User LOGOUT is selected. It is a
requirement of S.W.I.F.T. that the CBT is logged in to at least receive messages for at least 7
hours per business day. All of the terms in upper case represent messages.
S.W.I.F.T. addresses
S.W.I.F.T. addresses are used to not only indicate the final destination of the message but to
also indicate parties within the individual message. It is the use of strictly codified addresses
that enables the automation of Straight Through Processing in conjunction with the fixed tag
format of the messages themselves. The term "S.W.I.F.T. address" actually only relates to a
subset of Bank Identifier Codes (BICs), in other words you do not have to be a user of the
S.W.I.F.T. network to have a BIC and these can therefore be used over other networks such
as Telex. S.W.I.F.T. are, however, the recognised ISO (International Standards Organisation)
The first four characters represent the Bank code, for example NWBK (NatWest), DEUT
(Deutsche Bank).
The next two characters represent the ISO Country code, for example GB (United Kingdom),
DE (Germany).
The next two characters are the location code with some larger financial centres such as
London and New York having two, 2L and 22, 33 and 3N respectively.
These characters, the first 8, represent the mandatory portions and commonly within the
body of a message this will be the normal format, for example NWBKGB2L (NatWest
The presence of 0 (zero) in position 8 indicates that this is a test & training address. Test &
Training is a facility which S.W.I.F.T. gives its users to test new releases without interfering
with live operations. When an organisation first joins S.W.I.F.T. they must spend two months
sending messages in test & training before they are allowed to go live. S.W.I.F.T. monitor
this!
Optionally a three character branch code can be added at the end of the address. For
example NWBKGB2LBIR might be the Birmingham branch. These codes are primarily used
for internal routing purposes within the bank, as the branches themselves do not have direct
connection. Usage is often more common in some countries than others such as the heavy
The Logical Terminal ID in position 9 will be present in the header of the message and
identifies a logical channel connection to S.W.I.F.T.. Some organisations may run more than
1 LT on the same CBT and these will be referred to as A, B, C, etc. For example
NWBKGB2LA. These are not published in the BIC directory and so all addresses within a
message identifying the sender or other parties will not contain this character.
LTs will therefore always be padded out to 12 Characters by X's and S.W.I.F.T. addresses are
The presence of a 1 in position 8 denotes that this is not a S.W.I.F.T. address but the
organisation has requested that an ISO identifier be allocated to them. For example
NWBKGB21. Therefore, this address can be included in the body of a message but you
The presence of an X in position 8 denotes that the CBT which is processing traffic for this
address is not physically in the same country as the Country Code states.
S.W.I.F.T. messages are identified in a consistent manner. They all start with the literal "MT"
which denotes Message Type. This is then followed by a 3 digit number. The first digit
represents the Category. A category denotes messages grouped together because they all
The second digit represents the Group denoting that the messages are related to similar
The last digit is the Type and denotes the individual message. There are several hundred
Each message is assigned unique identifiers. A 4 digit session number is assigned each time
the CBT logs in. Each message is then assigned a 6 digit sequence number. These are then
combined to form an ISN (Input Sequence Number) from the CBT to S.W.I.F.T. or an OSN
(Output Sequence Number) from S.W.I.F.T. to the CBT. It is important to remember that
terminology is always from the perspective of S.W.I.F.T. and not the user.
The Logical Terminal Address (12 character BIC), Day, Session and Sequence numbers
combine to form the MIR Message Input Reference and MOR Message Output Reference
respectively.
We will concentrate on the structure of FIN messages as they are by far the most important
for the end user. They have the following general structure:
Block 3 is optional. Many applications, however, populate this with a reference number so
that when the Acknowledgement is returned by S.W.I.F.T. it can be used for reconciliation
purposes.
The application header has a different format depending on whether it is being sent to or
from S.W.I.F.T..>/p>
c) Message Type
b) O = Output
c) Message Type
g) Message priority
(a) (b) ( c)
This is an optional block and is similar in structure to system messages.
c) Message User Reference MUR used by applications for reconciliation with ACK
Other tags exist such as 119 which can contain the code ISITC on an MT521 or 523 providing
the sender and receiver are registered to do so with S.W.I.F.T.. This forces additional code
word and formatting rules validation of the body of the message as laid down by ISITC
This block is where the actual MTnnn message is specified and is what most users will see.
Generally the other blocks are stripped off before presentation. The format is as follows:
{4:<CrLf>
:20:PAYREFTB54302<CrLf>
:32A:970103BEF1000000,<CrLf>
:50:CUSTOMER NAME<CrLf>
AND ADDRESS<CrLf>
:59:/123-456-789<CrLf>
BENEFICIARY NAME<CrLf>
AND ADDRESS<CrLf>
-}
The symbol <CrLf> is a control character and represents Carriage Return/Line Feed (0D0A
The example above is an MT100, Customer Transfer with only the mandatory fields
completed. Fields must be in the order as specified in the appropriate volume of the user
handbook, there is one or more for each message category. It is an example of the format of
an ISO7775 message structure. These are gradually being replaced by the newer data
:nna:
nn - numbers
nn - maximum length
line length
n - Digits
h - Uppercase hexadecimal
a - Uppercase letters
c - Uppercase alphanumeric
e - Space
Some fields are defined as optional and if not required they must not be present as no blank
In some message types certain fields will be defined as conditional, i.e. if a certain field is
present then another field may change from optional to mandatory or forbidden. Certain
fields may contain sub fields in which case there is no CrLf between them.
Certain fields have different formats dependant on the option which is chosen, which is
Head Office
London
{5: {MAC:12345678}{CHK:123456789ABC}
using a key that has been exchanged with the destination and a secret algorithm. Found on
PDE: Possible Duplicate Emission added if user thinks that they may have sent the message
previously
PDM: Possible Duplicate Message added by S.W.I.F.T. if they think that a message may have
DLM: Added by S.W.I.F.T. if an Urgent message has not been delivered within 15 minutes or
ISO 7775, 15022, 20022/UNIFI history and current SWIFT MT and MX standards
In the late 1990's S.W.I.F.T. realised that the original ISO7775 messages were too restrictive,
did not reflect the full complexity of modern trading instruments and were still too
Thus was born the ISO15022 standard based on a data dictionary approach. Initially (in
1997) these were applied to the Securities message category as this represented the fastest
growing usage of the network. Old message types were replaced and many new ones
introduced. Trade Initiation and Confirmation messages were introduced in 1997 and
Settlement and Reconciliation in 1998. There was no standards release in 1999 due to Y2K
distractions, and the old message types were removed from the network in 2002.
It is still common for the original ISO7775 message types to be used for "off net" messaging
outside of the S.W.I.F.T. network. Typically older legacy applications may generate or
consume these message stuctures, and some firms private networks utilise specialised
in block 4 (note that all other blocks are unaffected). ISO15022 introduced the concept of
Generic Fields. This is aimed at uniquely identifying information. In the previous ISO7775
messages the same tag could appear in a number of message types but with a different
:2n1a: :4a/8a/data
Where:
For example:
The ISO15022 messages also introduced much more complexity with the concept of many
iterating repeating groups. These groups in turn can be nested and designated as
mandatory, optional or conditional. For example, :16R: Denotes start of a block or sequence,
:16S: Denotes end of a block or sequence, therefore 16R with contents SETPRTY denotes the
start of the Settlement Parties Sequence. 16S with SETPRTY denotes the end.
With the evolution of XML technology in the late 1990's work began on what was called
ISO15022 2nd Edition (also known as SWIFTML or SWIFT XML). This evolved into ISO20022
models and XML Schema based message data models for the transactional messages
supporting these models. The ISO20022 standard has further evolved to incorporate lessons
from the first implementations of ISO20022 Funds messages, FpML, FIX, ACCORD, MDDL and
others providing examples of successful best practice for ISO20022 to converge with. ISO
has published a series of standards such as ISO 15000 ebXML that overall ISO standards
In 2004 a significant increase in scope was agreed for ISO20022, it was rebranded the
"ISO20022 - UNIversal Financial Industry (UNIFI) message scheme", and expanded from
Securities and related financial instruments to the broader scope of all Financial Services.
Ownership of the standard itself moved to ISO/TC68 (the Financial Service technical
committee) from its SC4 (Securities and Related Financial Instruments sub-committee).
SWIFT then assumed the role of the Registration Authority (RA) for the ISO20022/UNIFI
standards with responsibility to ensure compliance of developed Repository items with the
SWIFT also introduced, or in the case of SWIFTNet Funds reintroduced, the "SWIFTNet
Solutions" products and standards covering specific business domains. The SWIFT
compared to the older SWIFT FIN standards being the MT standards. The SWIFT MX
Standards are conceptually the same as the ISO15022 standards, in that the respective ISO
standard specifies the message payload and then wraps this inside SWIFT specific
header/footer envelope. For example the SWIFT FIN MT541 block 4 body part is the
ISO15022 standard, while the complete MT541 with blocks 1,2,3 and 5 is...well...the MT541.
Similarly the SWIFT MX messages wrap the ISO20022/UNIFI payload or body inside the
with other standards, and the implementations in which they are used such as SWIFT MX,
TWIST, the Single European Payments Area (SEPA) are active areas of ongoing IONA
development and participation with the standardisers themselves. We remain very much
standards, to the current, and the next, all based on the same open model driven
integration approach.
Most users of S.W.I.F.T. have operations large enough in terms of transactional volumes that
the manual keying of data is not viable, even if the potential for human error is ignored. The
main challenge for organisations is therefore how best to automate the process. This
broadly speaking involves two main areas. Firstly how do you physically gain access to the
transactional data that underlies the message, in other words what is the transport going to
The approach to the automation of the process will also be driven by many variables: