ISO 20022

MT messages are the old way banks tell each other to "move this money to this account." They were created in the 1980s, so the fields are limited. This format predates even SOAP-based web services.

Banks often can't include enough detail about the payment: Who it's for, why it's being sent, and the exact information the receiving bank needs to process it.

When that info is missing or formatted incorrectly, the receiving bank can't post the payment, leading to delays.

ISO 20022 is a data quality standard for traditional finance (tradfi), providing banks with a richer, structured format so the important details travel with the payment. The data is presented in a standardized format. Banks can verify and validate to avoid the back-and-forth.

This weekend, SWIFT disabled the old MT format. Any bank still using MT will have its messages rejected. This move forces everyone onto the modern standard, which prevents any further mishaps.