A Tui TV ad offering a "perfect summer holiday" which could only be taken in September or October has been banned.
A travel period between September 1 and October 31 was "unlikely to align" with consumers' understanding of the term summer holiday, the Advertising Standards Authority (ASA) concluded.
Following a complaint to the ASA, Tui argued its summer holiday season ran from April to October.
In response to the ruling, the company said the ad had been altered.
The television ad for Tui holidays in June featured a voiceover stating: "It's not too late to discover Turkey with Tui from £279 per person this summer...perfect summer holidays that put you in the middle", while on-screen text specified that the price applied to departures between 1 September and 31 October.
A viewer claimed the departure dates were not during the summer holiday period and complained the ad was misleading.
Tui said its summer holiday period ran from 1 April to 31 October, pointing out that the ad showed both adult-only groups as well as families.
Ad clearance agency Clearcast said the first two weeks of departures were still within summer months and suggested it would have been confusing to spell out that the offer covered summer and autumn.
The ASA said consumers would interpret the term "summer holidays" to mean holidays available for travel during June, July and August.
It ruled that the ad must not appear again in its current form, adding: "We told Tui UK to ensure that 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."
A Tui spokesman said: "We note the ASA's ruling and can confirm that we've already taken action to amend this advert for future use."