Passengers could unnecessarily be forking out big sums of money to sit next to their loved ones on flights.
The majority of airlines operating in the UK now charge customers extra if they want to chose what seat they sit in, as a way to make extra money and subtly bump up the price of an average seat.
How much the right to select your seat costs varies from company to company, as does the chance you'd be sat next to your flying companion anyway.
Most major airlines will automatically seat you with the people you booked with, even if you don’t pay up, according to a study by the Which? travel team.
If you are willing to play the odds and be sat apart if the gamble doesn't pay off, you could save a significant sum of money when heading on holiday.
A family of four on a specific British Airways flight from London to Tenerife would have paid £112 to pre-select standard seats, and £192 for selected seats with extra legroom.
However, 94% of BA customers who decided not to fork out extra were sat next to their travel buddy anyway.
EasyJet, which charges between £6.99 and £8.99 to select a seat, sits 93% of customers who don't pay next to their loved one anyway, according to Which?
Jet2 sat 90% of their passengers next to one another if they didn't buy a seat, which costs between £10 and £13.
Ryanair and Wizz Air are much more likely to separate passengers who don't fork out.
Just 66% of passengers who don't pay on the budget Irish airline are sat together, making the £10 to £19 required to chose a spot a little more tempting. That figure fell to 61% for Wizz Air, where seat selection costs between £14 and £21.
Jo Rhodes, deputy editor of Which? Travel, told Mail Online: "Our research suggests that, in most cases, passengers are wasting their money by paying for seat selection on the plane – which can be upwards of £100 extra for a family of four.
"Most airlines will almost always seat you with your travel companions even if you don't pay – the only real exceptions to this rule are Ryanair or Wizz Air.
"For those trying to make their holiday budgets go further this summer, this is an easy way to make some substantial savings."
While most groups of adults will probably begrudgingly accept the chance that they'll be sat away from their companions to avoid the charge, the story is a different one when it comes to adults and kids.
According to the Civil Aviation Authority, young children and infants accompanied by adults should be seated in the same seat row as the adult. When this isn't possible, children should be separated by no more than one seat row from accompanying adults.
Most airlines automatically keep adults and children together. Ryanair does, but by insisting that the adult pays for seat selection.