Birmingham authorities have asked for more information on Uber's business model and operations before granting it a new licence.
The not-a-taxi firm had a one-year licence to operate in the UK's second city, but this expired last month.
According to Reuters, the city regulator has extended the licence on a temporary basis until it gets what it wants from Uber.
"Officers in our Licensing team have temporarily extended Uber's private hire operator licence in Birmingham, whilst they seek clarity from Uber around its operating model," Birmingham City Council's acting director of regulation and enforcement Chris Neville said.
The move comes after widespread complaints about Uber's working practices and safety record, which left the business battling to have its licence reinstated in a number of major UK cities – the London appeal is due to start in the next few months.
The spate of denials followed revelations about Uber's failure to report potentially criminal activities to police – including an alleged sexual assault – and general concerns about safety.
Under new CEO Dara Khosrowshahi, who came on board after last year's big scandal about the mass data breach and subsequent cover-up, has made efforts to spruce up its image.
Uber has pledged 24/7 telephone support for users and to set up a system to report incidents to police, as well as yesterday launching a data-sharing scheme in London that it said would extend to Birmingham and Manchester in the coming months.
The firm's PR push also seems to include convincing the UK public it has taxpayers' money in mind, with a decision earlier this week to drop an appeal against its lost licence in York. According to local site York Mix, Uber said that "rather than take up valuable court time and costs we intend to apply afresh for a new licence in the near future".
And the efforts appear to have had a better impact in other cities: as well as recently having licences approved in Cambridge, Nottingham and Leciester, Sheffield City Council this week signed off on a five-year renewal after a brief suspension last year. ®