In this week's episode of Which? Shorts, we put 12 airlines and booking sites to the test, to get a snapshot of how well they performed when we posed as customers looking to carry out simple tasks.

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Opodo said in response: “Comparing the experience of a newly made booking at its first interaction with one involving multiple previous contacts naturally reflects different experiences. Our AI-driven system recognises the ongoing needs of our customers and prioritises accordingly the most effective assistance and escalation paths. This approach is not disingenuous and is designed to enhance the efficiency and effectiveness of our customer service."

Lastminute.com told us: "For security reasons, the system does not register the information if there are gaps or spaces when entering the booking reference and contact details. The chat gives information to customers and guides them. We take into consideration customer feedback and that is the reason why we gave autonomy to our customers through MyArea."

Wizz Air told us: "We do not accept these findings.’ It continued that the research was ‘misleading’, only asking ‘a handful of people to give their opinion and attempting to disguise it as representative. It is simply not accurate or fair."

Ryanair told us: "We don’t respond to Which? fake news stories or its equally fake and routinely inaccurate “surveys’’."

Vueling told us: "Occasional challenges are not indicative of our overall service quality. We continuously evaluate our procedures to guarantee the best customer service and take the areas of improvement pointed out by the survey very seriously."