Santander bikes and e-bikes across London have been left unusable after a tech issue.
Customers have been left struggling to access the bikes after a planned software update ran over schedule.
More than 12,000 bikes in London are thought to have been affected by the issue on both the Santander Cycles app and docking stations.
Commuters reported their frustration on Tuesday, saying that they were unable to get access to a Santander bike despite several attempts.
One said: “I walked a mile past four nearly full bike stations that wouldn't let me take a bike before having to get the tube into work.
“Not really what I pay my subscription for.”
Another added: “What is going on with the Santander bikes today!! The app, which hasn't worked for ages, still isn't working.
“Now my key has stopped working too. This is terrible service. This needs sorting ASAP.”
Apologising for the issue, Transport for London said it was working to “restore services as soon as possible”.