nipundhiman
6 days ago4 min read
The ISO 20022 migration nobody has tested: what UK banks need to know before November
The SWIFT hybrid mandate lands in November 2026. Most UK payment teams know a migration is underway. Fewer know what a failed migration looks like from the inside — and almost none have tested against it. I have spent fifteen years working inside financial services technology teams, and in that time I have watched firms spend millions on technology migrations while investing almost nothing in testing what those migrations do to the systems on the other side. The ISO 20022 tra