Yes, some airlines do allow children under two to fly for free or at a reduced fare without purchasing another seat. This policy is commonly known as the “infant-in-arms” policy. However, it’s important to note that the specific policies can vary between airlines, and there may be certain conditions or limitations. Here are a few points to consider:

1. Age limits: The age limit for children to be eligible for the infant-in-arms policy typically ranges from 0 to 2 years, depending on the airline. Some airlines may have different policies for infants up to a certain age, while others may require the purchase of a seat for children over a specific age or size.
2. Seat availability: When traveling with an infant in arms, you are not guaranteed a separate seat for the child. The child will usually sit on the parent’s lap throughout the flight. If the flight is not full and there are empty seats available, some airlines may allow you to use an additional seat for the infant at no extra charge, but this is subject to availability.
3. Documentation: Even if infants are allowed to fly for free, you may still need to provide proof of age for the child, such as a birth certificate or passport. Airlines may require this documentation during the booking process or at check-in.
4. Safety considerations: It’s important to be aware that holding an infant in your lap during the flight may not provide the same level of safety as having a separate seat with a proper restraint system, such as a child safety seat or a CARES harness. Airlines generally recommend that parents purchase a separate seat for their infant to ensure optimal safety during the flight.

To understand the specific policies and conditions regarding infants flying for free, it is recommended to check the website or contact the customer service of the airline you plan to travel with. They can provide you with the most accurate and up-to-date information based on their specific policies and regulations.