MT Message

An MT message is a financial message in the Message Type format created by SWIFT, the cooperative that runs the main network for messages between banks. Each MT message has a three-digit number that identifies its purpose, such as MT103 for a customer credit transfer or MT940 for an account statement, and a fixed structure of tagged fields. For decades, MT messages carried most of the world's cross-border payment instructions, foreign exchange confirmations, trade finance documents and securities messages.

MT messages are sent over SWIFT's store-and-forward messaging service, SWIFT FIN. They are being replaced by messages based on the ISO 20022 standard, known in the SWIFT community as MX messages, which carry richer and more structured data. The move from MT to MX is one of the largest changes in banking infrastructure in recent decades.

The first digit of an MT number shows its category:

• Category 1. Customer payments and cheques, including the MT103 single customer credit transfer and the MT102 multiple customer credit transfer.
• Category 2. Financial institution transfers, such as the MT202 for bank-to-bank transfers and the MT202 COV used for cover payments.
• Category 3. Treasury markets, including foreign exchange and money market confirmations.
• Category 4. Collections and cash letters.
• Category 5. Securities markets.
• Category 6. Precious metals and syndications.
• Category 7. Documentary credits and guarantees, such as the MT700 for issuing a letter of credit.
• Category 8. Travellers cheques.
• Category 9. Cash management and customer status, including the MT940 customer statement and the MT950 statement used between banks.

Messages ending in 99, such as MT199 or MT299, are free-format messages used for enquiries and other communication that does not fit a structured type.

An MT message is made up of blocks. A basic header identifies the sending institution by its Bank Identifier Code, and an application header shows the message type and receiver. An optional user header can carry service information, including the unique end-to-end transaction reference used by SWIFT gpi. The text block contains the business content, and a trailer holds checks added by the network.

Within the text block, each field starts with a tag between colons. In an MT103, for example, field 20 holds the sender's reference, field 32A the value date, currency and amount, field 50 the ordering customer, field 59 the beneficiary customer, and field 71A the charges code, showing whether fees are paid by the sender, shared or paid by the beneficiary. Field formats are strictly defined, including character limits and the permitted character set.

A typical cross-border payment through correspondent banking involves several MT messages. The sending bank sends an MT103 to the beneficiary's bank with full customer details. If the two banks do not hold accounts with each other, the funds move separately between their correspondents using an MT202 COV, a method known as a cover payment. Each bank then reports the movement to its account holders through statements such as the MT940 or MT950, and banks use MT199 or similar messages to investigate problems.

The SWIFT gpi service, introduced in 2017, added tracking and service-level rules on top of MT payments, using a unique end-to-end transaction reference carried in the header.

The MT format was designed when bandwidth and storage were expensive, and it shows its age. Fields are short, so names and addresses are often truncated. Much information sits in unstructured free text, which makes automatic sanctions screening and reconciliation harder. There is limited room for remittance information such as invoice numbers, and different banks may fill the same field in different ways. Mapping between MT and newer formats can lose data, which is a recurring concern during migration.

SWIFT and the banking industry agreed to move cross-border payments and cash reporting from MT to ISO 20022. A coexistence period, during which both formats were allowed for cross-border payment instructions, began in March 2023 and was scheduled to end in November 2025. Over the same period many high-value domestic systems, including the euro area's T2, the UK's CHAPS and the US Fedwire Funds Service, moved to ISO 20022. MT messages remain in use for other categories, such as securities and trade, and many banks still operate internal systems built around MT formats, converting messages at the edge of their networks.