Flying with an infant can add a layer of complexity to any journey, but when you’re traveling on a low-cost carrier, the stakes become even higher. These airlines have built their business models around unbundled fares and ancillary fees, which means every service—including carrying a tiny passenger on your lap—may come with a price tag and a set of strict conditions. Understanding the fine print before you book is not just smart; it’s essential to avoiding budget-busting surprises at the airport.

This guide unpacks the infant policies of popular low-cost airlines around the world, explains the reasoning behind their rules, and provides actionable strategies to help you navigate the system. Whether you’re a first-time parent or a seasoned traveler, thorough preparation can transform a potentially stressful experience into a manageable, even pleasant, flight.

Why Low-Cost Carriers Have Stricter Infant Policies

At first glance, charging a fee for an infant who will spend the entire flight on a parent’s lap seems harsh. However, low-cost carriers operate on razor-thin margins and rely heavily on operational efficiency and ancillary revenue. An infant, even one not occupying a designated seat, still represents a passenger who must be accounted for in weight and balance calculations, safety briefings, and manifest documentation. Airlines also incur indirect costs such as administrative processing and liability insurance.

Moreover, the traditional full-service model often bakes infant accommodations into higher ticket prices. Low-cost carriers strip out these services to offer lower base fares, then add fees for anything beyond the bare-minimum transportation. This à la carte approach means the family market is not their primary demographic, and the policies reflect a focus on maximizing revenue per passenger and per flight segment. Recognizing this business logic doesn’t make the fees more pleasant, but it helps you anticipate them and budget accordingly.

Defining an "Infant" – Age Cutoffs and Requirements

Across nearly all airlines, an infant is classified as a child under 2 years of age (24 months) on the date of travel. The cutoff is consistent: once a child reaches their second birthday, they must have their own purchased seat and are subject to the standard fare rules, even if the trip was booked before the birthday. This rule is strictly enforced because it aligns with safety regulations regarding lap-held children and the use of child restraint systems.

For international flights on budget carriers, the age definition remains the same, but you must confirm that your infant will be under 2 for the entirety of the itinerary. If you are booking a round trip that spans the child’s second birthday, the return flight will require a separate seat reservation at the child’s current age. In other words, the infant rate only applies to segments where the child is younger than 2. Many parents have been caught off guard by this detail, so double-check your dates carefully.

Proof of age is mandatory. Most low-cost airlines require you to present a birth certificate or a passport at check-in for domestic flights, and a passport for international travel. Some may accept a certified copy of a birth certificate, but a hospital-issued souvenir document is rarely sufficient. The name on the infant ticket must exactly match the documentation, so triple-check spelling before finalizing the booking.

Infant Ticketing and Fees: The Devil in the Details

The most common scenario is the lap infant, where the child sits on an adult’s lap for the duration of the flight, secured by a supplementary loop belt provided by the cabin crew during takeoff, landing, and turbulence. Despite occupying zero physical seats, a lap infant almost always incurs a fee on low-cost carriers. This fee is often a fixed amount per one-way segment, though it can be calculated as a percentage of the adult fare plus taxes and surcharges. It is not unusual to see infant charges ranging from $25 to $50 on short-haul routes within Europe and North America, and $75 to $150 or more on long-haul budget flights.

Here’s where it gets complicated: some airlines charge the infant fee at the time of booking, while others add it at the airport check-in counter. The latter practice can lead to shock if you assumed the infant was flying free. Always research the specific carrier’s policy by visiting their official website. For instance, Ryanair requires that all infants be added to the booking and pay a flat fee, while Southwest Airlines allows a child under 14 days old to travel free on a domestic flight as a lap child without a fee on their parent’s ticket, but charges taxes on international itineraries. Check Ryanair’s infant policy or Southwest’s family boarding details for current specifics.

Separate seat purchases for infants are handled differently. If you want your baby to have their own seat—often recommended for safety and comfort on longer flights—you must buy a child-priced or adult fare ticket. Some low-cost carriers offer a discounted child fare, but many do not; you may end up paying the full adult base rate. Additionally, you will need to bring an FAA-approved (or equivalent regulatory body) child restraint system, as the airline seatbelt alone is not designed for a small child under 2. The airline’s website will specify approved harnesses and car seats. Airlines like AirAsia and easyJet give parents the option to purchase a seat for an infant and bring a certified car seat on board, but this must be arranged in advance.

Seat Policies, Bassinets, and Onboard Comfort

Lap seating is permissible only for one infant per adult. Two infants cannot share one adult’s lap, so parents traveling alone with twins or multiple children under 2 will need to purchase an extra seat for the second child and bring an approved car seat, or have another adult traveling with them. Some carriers, like Spirit Airlines, explicitly limit one lap infant per adult over the age of 15, so confirm the adult’s age requirement as well.

Bassinets or skycots can be a game-changer on long-haul low-cost flights, but availability is extremely limited and not all low-cost long-haul carriers offer them. Airlines such as Scoot and AirAsia X provide bassinets on certain aircraft, but these are usually reservable for infants weighing under a specific limit (commonly 10-11 kg or 22-24 lbs) and who meet a length restriction. The bassinet is typically attached to the bulkhead wall, which means you must book the bulkhead seats—often subject to an additional seat selection fee. Because bassinet positions are scarce, you should reserve one as early as possible, ideally at the time of booking. Check with the airline directly; many do not guarantee a bassinet even after a request, and they operate on a first-come, first-served basis at the airport.

If you are purchasing a separate seat and using a car seat, remember that the device must be certified for aircraft use and fit within the seat dimensions. Rear-facing car seats are permitted, but they can encroach on the space of the passenger in front. Therefore, the airline may require the car seat to be installed in a window seat, not in an aisle or middle seat, to avoid blocking egress. This is not an arbitrary rule; it aligns with safety regulations enforced by aviation authorities such as the FAA in the United States and EASA in Europe. Consult the FAA’s guidance on flying with children for detailed safety recommendations.

Baggage Allowances for Infants: Strollers, Diaper Bags, and More

Baggage policies for infants on low-cost carriers are another area where fine print matters enormously. While some full-service airlines provide a generous checked baggage allowance for infants, budget airlines often include only the bare minimum. Typically, a lap infant does not get a carry-on bag allowance, though the adult traveling with the infant may be permitted to bring an additional small bag free of charge, often described as a changing bag or diaper bag. This is not universal; some airlines count that extra bag as part of the adult’s carry-on limit.

Collapsible strollers and car seats are almost always allowed as checked items without a fee, as long as they are checked at the gate or ticket counter. However, double-check the fine print: some airlines will only accept one collapsible pushchair and one car seat per child, and they must be tagged appropriately. Gate-checking a stroller can be a lifesaver as it allows you to wheel your baby to the aircraft door, but board early because space in the gate-check hold is limited. Car seats that are not used on board usually must be checked; some airlines allow them to be checked free, while others may count them as part of your existing checked baggage allowance. For example, easyJet permits two items—a pushchair and a car seat—to be taken in addition to your own cabin bag allowance, all free of charge. More about easyJet’s infant luggage rules can be found on their site.

Food and milk for the infant are exempt from liquid restrictions, but you must present these items separately at security screening. Breast milk, formula, and baby food in reasonable quantities for the flight are permitted. Pack these in accessible containers, and be prepared to open them if requested by security personnel. Frozen gel packs to keep milk cool are also allowed. Bottle warmers, however, may be subject to additional scrutiny or prohibited, depending on the airport’s rules.

Check-In and Boarding Strategies

Most low-cost carriers require online check-in, and often the infant’s presence triggers unique requirements. If you have a lap infant, you may not be able to check in entirely online because the airline needs to verify the age documentation in person. This means you must arrive at the airport early and head to the full-service counter, not just the bag drop. Budget extra time—45 to 60 minutes beyond what you would normally allow—to avoid missing the flight due to long queues.

When checking in, you’ll present the infant’s proof of age, any necessary visas or passports, and sometimes a completed medical clearance form if the infant is very young (typically under 7 days old). Airlines set a minimum age for newborn travel, often ranging from 2 days to 14 days, and a medical certificate may be required for infants under a certain threshold. If your baby was born prematurely, the airline may require a fitness-to-fly letter from a pediatrician regardless of chronological age. Never assume the carrier will allow a newborn on board without documentation; call ahead to verify the policy.

Boarding priority for families is not guaranteed on low-cost carriers. Some airlines, such as Southwest with its family boarding between groups A and B, offer a designated boarding time for those traveling with young children. Others, like Ryanair, have no priority for families unless you purchase priority access. Without it, you will board in the general queue, which can be chaotic and stressful with an infant. Purchasing priority boarding or seat selection may be a worthwhile investment to secure overhead bin space and settle into your seat calmly.

International Travel with Infants on Budget Airlines

When crossing borders, the infant’s documentation requirements match those of any passenger. A valid passport is mandatory for international flights, even for a newborn. Some countries also require a visa for the infant, which must be obtained in advance. The infant ticket for an international low-cost flight will typically include the base fee plus applicable government taxes and airport charges, which can sometimes be surprisingly high. While the infant might not pay a fuel surcharge, they are not exempt from all taxes, so the total infant fee can be substantial.

At the destination, local regulations may require additional paperwork, such as a notarized letter of consent if the child is traveling with only one parent. This is not airline policy but immigration policy, and the airline may deny boarding if you cannot produce the required documentation. Research the entry requirements for your destination country well ahead of time, and carry multiple copies of all essential documents.

Furthermore, time zones and long-haul flight fatigue can disrupt an infant’s routine. Plan ahead by booking flights that align with your baby’s sleep schedule whenever possible. While a low-cost carrier’s sparse schedule may limit your choices, even a small shift can make a difference. Bring more supplies than you think you will need—diapers, formula, and changes of clothes—because finding them in an unfamiliar airport at 2 a.m. is a challenge you do not want to face.

How to Minimize Costs and Avoid Hidden Charges

Despite the nickel-and-diming reputation of budget airlines, you can keep infant travel costs in check with a proactive approach:

  • Book early and research thoroughly. Infant seats, bassinets, and even the ability to book a lap infant online can be limited. The earlier you book, the more options you have to choose your preferred flight and the less you risk missing out on essential accommodations.
  • Compare all-in infant fees. Do not just look at the base adult fare. Visit the airline’s infant policy page and calculate the total infant fee, including taxes and any seat assignment charges. Factor this into your comparison when choosing between carriers.
  • Consider buying a seat. On short hops, a lap infant is manageable, but on flights exceeding two or three hours, the safety and comfort of a dedicated seat with a car seat can be worth the extra cost. Sometimes child fares are discounted enough that the difference is negligible, especially if you avoid the lap infant fee.
  • Maximize free allowances. Take advantage of the free stroller and car seat check-in. Pack the diaper bag strategically so it qualifies as the permitted extra bag without triggering a fee. If the airline doesn’t allow a free diaper bag, use packing cubes within your own carry-on to keep infant supplies organized without exceeding your baggage allowance.
  • Join loyalty programs. Even low-cost carriers have frequent flyer programs or co-branded credit cards that can provide benefits like free checked bags, which indirectly help with all the extra gear an infant requires. While the infant themselves won’t earn miles, the adult’s status can smooth the journey.
  • Be flexible with airports. Some regional low-cost carriers serve secondary airports that may have less congestion and shorter security lines, reducing stress. Just ensure that ground transportation with an infant is still practical.

Real-World Policy Roundup: Key Differences Across Carriers

To give you a head start, here is a snapshot of how some major low-cost carriers handle infants. Note that policies are updated frequently, so always verify on the airline’s official website.

  • Ryanair (Europe): Infants under 2 may travel on an adult’s lap for a flat fee per one-way flight. A separate seat cannot be booked for an infant; they must be on a lap. A collapsible pushchair is carried free of charge, and one small baby bag (up to 5kg) is allowed on board. Check their children’s travel FAQ.
  • easyJet (Europe): Infants under 2 pay a fixed fee per flight if sitting on an adult’s lap. Alternatively, you can book a seat for an infant and use an approved car seat. Free of charge, you can bring two items: a pushchair or travel cot and a car seat. The adult accompanying the infant can bring a changing bag in addition to their own cabin bag.
  • Southwest (USA): One lap child per ticketed adult can travel free of charge on domestic flights; for international travel, taxes and fees apply. A birth certificate is required for age verification. Southwest allows early boarding between groups A and B for families with young children, and offers a car seat for purchase on board if using a separate seat.
  • AirAsia (Asia): Infants must pay a fee that varies by route, and they can only sit on an adult’s lap. Bassinets are available on certain aircraft for long-haul AirAsia X flights, subject to weight/size limits. A stroller or car seat can be checked free, but other infant items count toward your baggage allowance. Details are on AirAsia’s infant travel page.
  • Scoot (Singapore): As a medium-to-long-haul low-cost carrier, Scoot charges an infant fee based on the adult fare plus taxes. Bassinets are available on Boeing 787 Dreamliner flights for infants under 10kg, bookable for an extra fee. A stroller and a car seat each count as one piece of checked baggage, but you get additional free 10kg of check-in baggage on certain fare types.

Final Preparation Checklist

Before you head to the airport, run through these steps to ensure you have not overlooked any critical detail:

  1. Read the airline’s infant policy page from their official website—do not rely on third-party summaries.
  2. Confirm that your infant’s ticket has been added correctly to your booking and that the name matches the birth certificate or passport.
  3. Print or download digital copies of all necessary documentation: proof of age, passport, visas, medical clearance if needed.
  4. Pack a well-stocked diaper bag: diapers, wipes, change of clothes, formula, and comfort items. Keep liquids accessible for security screening.
  5. Charge all electronic devices and download entertainment that can distract an older infant or toddler—even if they have a seat, boredom can strike quickly.
  6. Arrive at the airport with ample time; consider airport lounges if they provide a quiet space for feeding and changing.
  7. Gate-check your stroller if possible, and attach a clear luggage tag with your contact information.
  8. Board the aircraft slowly and don’t be afraid to ask flight attendants for assistance or clarification—they are trained to help, even on budget airlines.

Traveling with an infant on a low-cost carrier does not have to be an ordeal. The fine print, once dissected, reveals a predictable set of requirements that you can plan around. By anticipating fees, understanding baggage rules, and securing any necessary seat add-ons early, you can keep your trip affordable and your family’s journey as smooth as possible. Budget airlines may not offer the frills, but with the right preparation, you can still enjoy the adventure of flying together.