Drop-off fees have increased at two-thirds of the UK's major airports since 2019, according to research.
An RAC investigation found 16 of the 22 airports analysed have introduced or raised charges for dropping off passengers in the past three years.
The motoring services company claimed drivers will be "stunned" by some of the "sky-high" fees.
Stansted Airport is the most expensive for so-called kiss-and-fly charges, which are typically levied for dropping off someone as close to the terminal as possible.
Its initial fee is £7 for up to 15 minutes - an increase from £4 for 10 minutes in 2019, before the pandemic.
Stansted said the charge "makes an important contribution to encouraging alternative, more sustainable transport options" and reduces congestion.
It is one of many airports that offer free options for dropping passengers off in mid or long-stay car parks connected to terminals by buses.
Eight airports charge £5 for dropping off passengers. They include the UK's two busiest airports, Heathrow and Gatwick, which introduced the charge last year.
Nicholas Lyes, RAC head of roads policy, said limited public transport options for some airports and concerns about train strikes mean many passengers are asking a friend or relative to give them a lift.
"Anyone dropping a loved one off at the terminal this summer will be stunned by some of these sky-high, kiss-and-drop charges," he said.
"Minute for minute and pound for pound, some of these charges could almost be as high as the airfare itself."
He said it appears many airports have increased fees to "partially make up" for lost revenue during the pandemic.
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Manchester Airport gives drivers five minutes to drop off travellers for £5 (up from £3 in 2019), while Liverpool John Lennon Airport has raised its fees from £3 for 20 minutes to £4 for 10 minutes. Bristol Airport has hiked its initial fee for 10 minutes from £1 to £5.
In Scotland, dropping off passengers at the three biggest airports is not much cheaper.
Edinburgh, Aberdeen and Glasgow airports have all doubled their fees in the past three years to £4 for 10 minutes.
Birmingham and Belfast International have kept their fees the same since 2019 (£3 for 15 minutes and £1 for 10 minutes, respectively), while drivers can still take advantage of free drop-off areas near terminal entrances at Cardiff, London City and Belfast City.
Mr Lyes has advised drivers to research charges before heading to airports, and warned them to be aware that many sites use cameras to enforce bans on stopping in certain areas.
The Airport Operators Association, an industry body, said airports provide clear information about parking and drop-off charges to ensure travellers are "well-informed on the range of options to suit their needs".
The spokesman added: "Airports that operate drop-off charges directly outside the terminal do so for a number of different reasons, including to manage congestion in capacity-restricted areas and to limit the environmental and air quality impacts of 'kiss and fly' journeys."