Taxify, the Uber rival that operates in 26 European, Middle Eastern, and South African cities, has temporarily stopped its London services just three days after launch. The decision follows an investigation by Transport for London (TfL) over concerns that Taxify doesn’t have a license to operate in the city.

Much like Uber, Taxify describes itself as technology company rather than a taxi firm. To allow it to operate in London, it purchased a private hire company called City Drive Services that is licenced until 2019. But it seems the TfL wasn’t happy with the arrangement.

“Taxify is not a London licensed private hire operator," a TfL spokesperson said. "We are urgently investigating the nature and extent of its activities and will take action where appropriate.”

The transport authority later added: “The law requires private-hire bookings to be taken by licensed private-hire operators at a licensed premises, with appropriate record keeping. Taxify is not a licensed private hire operator and is not licensed to accept private-hire bookings in London.”

Taxify explained in a statement that it had “temporarily stopped operations to clarify its legal position with the regulator.”

Having first launched in Estonia in 2013, Taxify offers a 15 percent commission rate to its drivers and claims to use the same pricing system as its competitors. It arrived in London on Tuesday with over 3,000 registered drivers and over 30,000 customers downloading the app in the first three days.

As the company charges up to 10 percent less for fares compared to Uber, and is offering 50 percent off during its first month in London, residents will likely hope that Taxify’s operations return to the streets soon.