Paying extra for a specific plane seat might be the last thing you want to do when planning an already costly trip abroad.

Thankfully experts at Martin Lewis' MoneySavingExpert (MSE) highlight a lesser-known method of securing a better spot with easyJet for free.

What sets easyJet apart from many other airlines is its policy of allowing passengers to check in 30 days before a flight. When you do this, you and your travel companions will be assigned a specific seat on the plane, with its location determined by what's been allocated to other passengers.

Although this may seem simple, MSE experts emphasise that the earlier you check in, the more likely you are to be assigned a 'better seat', potentially next to your family and friends. Delay this, and you will perhaps receive the less desirable spots instead. 

"Unlike other airlines, easyJet lets you check in and allocates you a seat 30 days before you fly, free," the MSE specialists explain online. "You'll have to pay if you want a specific seat, but the earlier you check in, the more likely it is that you get allocated a better seat."

Adding to this, easyJet's website states: "If you don't select a seat we'll assign seats randomly for free when you check in and will do all we can to ensure everyone on the booking sits together. However, this is not guaranteed, especially when checking in closer to departure. Fees vary depending on the route selected, flight and time of booking."

If you'd rather avoid the risk, easyJet offers various seating options on its website, starting from just 99p for shorter flights. You can also book extra legroom seats from £12.99, while other seats located at the front or over the wing are priced from £7.99 and above.

As part of its policy, easyJet aims to seat children under 12 near an adult as well, and infants can sit on an adult's lap for a fee of £25. It's essential to inform easyJet if you're travelling with children by adding their details during the booking process.

Advice from easyJet reads: "If you're travelling with children it's important that you tell us when making a booking. Simply add the number of children and infants and their ages during the booking process.

"If you haven't yet bought seats for your family the best way to ensure everyone is seated together is to check in as early as possible. Check in opens 30 days before departure and we recommend you check in as early and possible and no later than seven days before your flight.

"Whilst our seating system will always try to seat families together, seats are allocated on a first come first served basis so the earlier you check in the more likely you are to be seated together.

"If you leave it to the last minute it's possible that there may not be enough seats left for us to seat your family next to each other. We'll still make sure each child under 12 is seated close to an adult on your booking.

"However we may only be able to arrange this at the airport or on board, which can cause delays for you and other passengers, and not everyone may be seated together."

For additional information, head to easyJet's website.