The advert, aired in June, promoted a range of late deals on travel to Turkey during September and October.
“It’s not too late to discover Turkey with Tui from £279pp this summer... perfect summer holidays that put you in the middle,” said the voiceover.
Accompanying on-screen text added: “Departures between 01/09/2018 and 31/10/2018 flying from selected airports.”
The Advertising Standards Authority (ASA) received a complaint challenging whether the departure dates were during a recognised “summer holiday period” in the UK.
Tui said its summer holiday period ran from April 1 to October 31, stressing the ad also highlighted adult-only trips as well as family holidays.
Ad clearance agency Clearcast added the first two weeks of Tui’s departures (in September) fell within a recognised summer period.
The ASA though said consumers would interpret the term “summer holidays” to refer to travel during the calendar months of June, July and August, including the school holidays.
It ruled the ad was misleading and must not appear again in its current form.
“We acknowledged Tui’s comments regarding their own summer holiday period and the use of both adult and family oriented groups within the ad.
“We also acknowledged Clearcast’s comments the first two weeks of departure were still within the astronomical summer period, which ran into September.
“However, we did not consider a travel period of September and October only was likely to align with consumers’ understanding of the term in the context of the ad.
“Because the offer was not available for travel during the summer months of June, July and August, we concluded the ad was misleading.
“We told Tui to ensure their future advertising did not mislead by claiming to offer summer holidays if those holidays were outside of the period that consumers were likely to consider as summer.”