The Competition and Market Authority said following an investigation into the secondary ticketing sector, the firm had failed to overhaul the way it does business.
Legal proceedings have therefore been brought in the High Court.
The CMA started enforcement action against four secondary ticketing websites in November last year. Three of them – StubHub, GETMEIN! and Seatwave – committing to change their business practices.
However, the CMA said: “Despite being warned a failure to do likewise would result in court action, Viagogo has not offered to make the changes the CMA considers necessary to bring it in line with the law.”
The watchdog is concerned Viagogo is breaking several aspects of consumer law.
Specifically, Viagogo customers are not being told if there is a risk they will be turned away at the door, not being informed which seat in the venue they will get and not being told who is selling the ticket.
In addition, they are being given misleading information about the availability and popularity of tickets, experiencing difficulties in getting their money back when things go wrong and being offered tickets that a seller does not own and may not be able to supply.
CMA boss Andrea Coscelli said: “People who buy tickets on websites like Viagogo must be given all the information they are entitled to.
“It’s imperative they know key facts, including what seat they will get and whether there is a risk they might not actually get into the event, before parting with their hard-earned money.
“This applies to Viagogo as much as it does to any other secondary ticketing website.
“Unfortunately, while other businesses have agreed to overhaul their sites to ensure they respect the law, Viagogo has not. We will now be pursuing action through the courts to ensure that they comply with the law.”
The CMA is now seeking a court order to bring these practices to an end and make sure Viagogo does not repeat historic failures.
It is also seeking an interim enforcement order from the court that, if successful, will put a stop to some practices in the period up until the full trial.