Should you buy your baby a seat on a plane?

So, babies don't fly for free?

No, not really. You are not required to buy a separate seat for an infant (commonly defined as a child over the age of 8 days and under the age of 2) but airlines can lawfully charge you for having an infant on your lap in your seat.

The charge for having an infant on your lap varies considerably between the different airlines. As a rule of thumb:

• For international long-haul flights, carriers like Virgin Atlantic, British Airways and Emirates charge 10% of the adult seat fare. Many of these larger airlines (such as American Airlines, Air New Zealand, United Airlines, Air France, Lufthansa and Qantas) do not charge for infants on their domestic flights, though, so, if your international flight includes a layover, you won't pay an infant fare on the domestic leg.
• On low-cost short-haul airlines, such as Ryanair, EasyJet, WizzAir and Jet2, there's a flat fare for lap-sitting infants (typically £25 to £35 one-way) or a charge based on a percentage of the adult fare (typically 10% to 12%, according to Skyscanner). Holiday company TUI are more secretive about their prices, stating that the infant flying fee varies depends on the flight, which really isn’t helpful.

And remember: all this is before you've consider any extra charges for baggage.

On budget-airline flights, babies on laps mostly don't get any hold luggage allowance, though you probably will be allowed to bring on an under-seat-sized baby bag for essentials (see Does a baby on a lap get a baggage allowance? below).

Larger airlines, such as British Airways and Virgin Atlantic, allow a lap-sitting infant to check 1 bag in the hold and carry on a small nappy bag.

Is it cheaper to buy my baby a seat?

It might be, especially if you are booking ahead for a low-season flight and travelling short-haul on a budget airline where tickets for an adult (there won't be a ticket option for a baby) can sometimes be less than the £25 to £35 infant-on-lap charge.

But non-budget airlines generally charge a percentage (often about 75%) of the adult fare to buy a seat for an infant. So, depending on your destination and the deal you've found for your tickets, it usually works out more expensive to buy the seat than pay the charge to have your child on your lap.

However, if it's a long flight, you might think this extra cost is worth it for the extra comfort of not having to have your child on your lap the entire time. (Some airlines allow you to bring a car seat into the cabin to help keep your baby sitting safely in their separate seat – see Can I take my baby's car seat on the plane? below.)

So, it really depends on how much you are paying for your fare, how long the flight is and how much luggage you need to travel with.

Do bear in mind that. on most airlines, even if pay for your infant to have their own seat, you will have to hold them on your lap for take-off and landing and during turbulence when the seatbelt sign is on (unless they are buckled in to a specialist seat, such as those supplied for free – if you book them – by airlines such as British Airways on long-haul flights).

Can I take my baby's car seat on the plane?

Yes, on many airlines, you can use a car seat to seat a child in the cabin, providing you have purchased a separate seat for your child and your child is under the age of 3.

To use a child car seat on an airplane it has to be CAA (UK Civil Aviation Authority), FAA (Federal Aviation Administration) or TÜV approved. You should be able to see if your child's car sear is approved in this way: if it is, it should have a 'certified for use in aircraft' sticker.

Almost all airlines allow front-facing child car seats for use in the cabin. Much fewer will allow rearward-facing and those that do will have extra requirements about the car seat's width and design: do make sure you check with the airline first.

Each airline tends to have its own 'small print' rules about car seats, so do check carefully before you book. The key thing to check is the width of your car seat – because different airlines will have different maximum permitted widths, depending on the width of their cabin seats. As a rule of thumb. any approved car seat with maximum width of 42cm should fit on a standard economy seat (including budget airlines).

The car seat needs to be buckled in, using the airline seat belt, and airline crew have to be satisfied that it safely fixed before they let you use it. Bear in mind, too, that some airlines require that child seats are only used in a window seat, so they will not block escape paths in an emergency.

• Which are the best car seats to take on a plane? We've found 10 great buys

Does a baby on a lap get a baggage allowance?

Almost universally not on a budget airline (small baby changing bags excepted) – and this might be something that, for you, swings the decision about buying your baby a seat instead.

Let’s take an easyJet, for example. In April 2023, the charge for an infant sitting on your lap is £25 each way and, for no extra charge, you can bring a 45cm x 36cm x 20cm baby changing bag into the cabin and put 2 baby-equipment items (such as a pram or a car seat) in the hold.

But that's it. All your baby's clothes and other items will need to go in your own bags or you'll need to purchase additional baggage allowance for yourself – that must go in the hold, not the cabin – to put your baby stuff in.

So, if you have a lot of stuff (not unusual when travelling with babies!), it could work out cheaper to book your baby a seat that comes with its own free cabin bag allowance, than to fork out for extra luggage allowance on your ticket.

On larger airlines, if you have purchased your infant a separate seat and that seat was not purchased on a hand-luggage only fare (such as Virgin Atlantic's Economy Light), your baby will usually get to check his or her own suitcase. Obviously on airlines where baggage is priced separately anyway, like on Ryanair, the same fees apply.

What about twins or a baby and a toddler? Can they both sit on my lap?

No, no airline will allow you to carry 2 babies on your lap. If you are flying with two or more children under 2, and they don't have their own seat, you cannot travel alone. You will need to fly with another paying adult or to pay the airline to provide an escort.

You can, of course, buy one seat for an infant, instead – and pay the charge to sit your other child on your lap.

What about bassinets? Do you pay extra for those?

A bassinet or sky cot is a detachable carrycot, set up on a bulkhead seat, that is sometimes available for those flying long-haul with a lap infant who cannot yet sit up on his or her own. Different airlines have different policies (and weight limits) on bassinets and some do charge for securing the bulkhead seat where the sky cots are located.

Whether there's a charge or not, all bassinets must be reserved or requested in advance. This is because there is a limited number on board. Even if you do manage to reserve a sky cot (either by paying for the seat or reserving one with the airline over the phone) there is no guarantee the bassinet will be available.

Bassinets have their pros and cons. On older airlines, babies have to be removed from the bassinet during turbulence, which can mean waking up an otherwise sleeping baby. Newer aircrafts with sky cot seats (which look like a baby bouncer, but are fixed), can be used during turbulence as they come with a secure harness. Airlines with this style include British Airways, Virgin Atlantic and Emirates on selected aircraft.

As you can see, there's quite a lot to consider!

However – and wherever – you're travelling, the key is to make sure you do your research on what your airline's infant charges and allowances are, and factor in all the costs – including whether it's worth paying a little more anyway for an additional seat to make the journey less stressful/more comfortable for you.

Read more:

• Best child car seats to use on a plane
• Can I take my buggy on a plane?
• How to sit families together on a flight