A minister has told consumers not to use Viagogo, one of the big four secondary ticket resellers.
Digital Minister Margot James said if fans had to use a secondary site to buy tickets, “don’t choose Viagogo – they are the worst”.
Her warning comes after the Advertising Standards Authority said Viagogo was breaking UK advertising rules by failing to make additional fees clear.
The Geneva-based firm was one of four subject to ASA action in March.
The advertising watchdog said Viagogo had agreed to make compulsory fees “sufficiently clear” by 26 May, but had failed to do so.
The other three big resellers – StubHub, Seatwave and GetMeIn – were also subject to the action against “drip pricing”, where VAT, booking and delivery fees were added at the end of the booking process.
The ASA has received 23 complaints about Viagogo from groups including campaigners Fanfair Alliance, and music promoters Festival Republic and Kilimanjaro Live.
Last month the Competition and Markets Authority said Viagogo would face legal action after failing to make changes it had demanded.
Its rivals StubHub, GetMeIn and Seatwave had agreed to provide better information about the tickets sold on their sites.
They must warn if buyers risk being denied entry, the exact seats they will get and who was selling the tickets.
However, the consumer watchdog said Viagogo had failed to give the same undertakings.
Reg Walker of the consultancy Iridium said Viagogo was no longer based in Britain and “seems to regard UK consumer protection legislation as a minor inconvenience”.
“It was also claiming to be an official site on Google paid advertisements and that again by the Advertising Standard Authority was deemed to be a breach of the code, so there is a long history here of Viagogo being non-compliant,” he told 5 live.