Sharia-compliant bank Al Rayan is shutting down its online banking service on 26 February, forcing its customers to switch to app-only banking with just six days notice.
The UK bank issued an e-mail to its customers, announcing this change and advising them they have six days to download Al Rayan's app if they want to continue to bank digitally.
Al Rayan has told consumer reviews site Which? it is making this move in response to growing customer demand for mobile-centric banking services and the greater security offered by two-factor authentication.
The announcement came as an unwelcome surprise to many customers who do not have the means to do their banking via a mobile app and those who do not wish to.
A number of customers made their frustrations known on social media, while Al Rayan has referred them to its telephone line for support though acknowledged this was experiencing higher call volumes than normal.
Devices must run iOS version 12 or Android version 8 or higher to use Al Rayan's app, which one customer described as a "disaster" for those that do not.
The bank has claimed that thousands of its customers are already using the app, and that those without a compatible smartphone will be provided "a hard-token" device, enabling them to continue accessing their accounts on a desktop.
Al Rayan's app is new and so is likely to be experiencing some teething problems, meaning customer frustrations may become more intense and more vocal after online banking is switched off.
The app currently has a three-star rating on the Apple app store on the basis of 74 reviews.