It was at the end of April 2022 that Swedbank was hit by an IT incident that resulted in nearly one million customers receiving incorrect balances on their accounts.
It looked like there was a lack of funds due to a large number of transactions being stopped in the systems.
The Financial Supervisory Authority's review shows that Swedbank made a change in the IT system without following its procedures.
The bank also lacked the right control mechanisms in this context.
Swedbank has therefore violated central rules on internal control, the authority states.
"The bank deviated from its own procedures.
This contributed to a very large number of people having extensive problems managing their basic banking services.
Close to a million customers received incorrect balances on their accounts and many were also unable to make payments," says Acting Director General Susanna Grufman in a press release.