Ride-sharing app Uber filed an appeal at the Westminster Magistrates' Court against the ban imposed by the Transport for London's (TfL) on September 22.
TfL said it took the decision on the grounds of "public safety and security implications".
Uber's licence officially expired on September 30 but the service can remain up and running until the legal process is exhausted, which could mean potentially a year or more.
Around 3.5 million passengers and 40,000 drivers use the Uber app in London.
The company said it will continue its discussions with TfL, which had ruled that the company was not "fit and proper" to operate in London on grounds of safety and security.
"While we have today filed our appeal so that Londoners can continue using our app, we hope to continue having constructive discussions with Transport for London. As our new CEO has said, we are determined to make things right," an Uber spokesperson said.
TfL "noted" the appeal but said it would not be commenting before the hearings, which are expected to start in December.
A TfL spokesperson said: "We note that Uber has submitted an appeal. No further comment will be made pending the appeal hearing."
Earlier this month, Uber's new chief executive, Dara Khosrowshahi, met Mike Brown, who runs Transport for London.
Uber described those talks as "constructive", while TfL said the talks "centred on what needs to happen to ensure a thriving taxi and private hire market in London".
He also apologised for the company’s past actions and promised to change.
London mayor Sadiq Khan has since indicated that the transport authority is willing to re-consider if safety concerns are addressed.
An online petition calling for the ban to be reversed has been signed by more than 850,000 people.
In making its decision not to renew Uber's licence, TfL had cited concerns including Uber's approach to reporting criminal offences, how it conducted medical and criminal checks on drivers, and whether software employed to evade regulation was being used in London.
Uber disputed the complaints, saying it had a special procedure for dealing with allegations of criminal offences.
Uber has also been criticised over its treatment of drivers who are employed by it, and is awaiting a separate tribunal ruling over the employment status of what it terms "partners".
It has been attempting to overturn a judgment that drivers – about 40,000 of whom work for Uber in London – have rights to paid holiday and the minimum wage.