The travel group was one of 100 companies sent an open letter by the Competition and Markets Authority (CMA) telling them to make refund policies clear and warning them of their legal obligations ahead of holiday travel resuming later this year.
Since March 2020, the regulator said it had received 23,000 complaints related to refunds and people not being able to travel due to COVID-19 restrictions.
TUI was the subject of action by the CMA last September and was highlighted again today with the group said to have agreed to provide clearer information on refunds ‘upfront to customers’.
The FTSE 250 group is one of five travel companies where enforcement action over refunds has been taken by the CMA, which the regulator said had seen £200mln returned to customers.
The other four are Teletext, LoveHolidays, Lastminute.com and Virgin Holidays.
Andrea Coscelli, the CMA’s chief executive, added: "International travel is set to resume soon and lots of people will be considering a long-awaited trip abroad. With that in mind, we want to make sure people are fully aware of their refund rights, so they can make informed choices about booking a holiday.
“We expect all firms to give clear cancellation options and will consider appropriate steps if we see companies breaking the law by refusing or delaying refunds this summer.”