On the 30th of May, the company we use to connect to Faster Payments had a technical issue, which meant a quarter of bank transfers into Monzo accounts were failing or delayed by several hours, and bank transfers from Monzo accounts were delayed by a few minutes.
There was an issue with a system that this company uses to translate payment messages from one internal format to another (they call this a “transformer”). This issue corrupted payment messages, which meant we couldn’t process bank transfers properly.
One of our payments engineers @nickrw has given a high level overview and broken down in technical detail what went wrong. As well as sharing our plans to make sure it doesn’t happen again in the future.
Again, we’re really sorry about what went wrong here. And rest assured we’re committed to fixing it.