Online check-in is available between 24 hours and one hour before the flight is scheduled to depart. Check-in times vary by airport - 90 minutes at Albany, 60 minutes at Boston, 120 at Oakland.

Carry-on: one item plus a personal item such as a handbag. Dimensions should be no bigger than 25 x 40 x 61cm (10 x 16 x 24 in).

Checked: the free baggage allowance is two pieces, weighing up to 22kg (50lbs) each with maximum dimensions of 157cm (62in) (length + width + height).

Excess: overweight items, between 23 and 45kg (51 and 100lbs) and oversized items in excess of 157cm (62in) but not more than 203cm (80in) will be carried for a fee of $50 (about £24) per item.

Seat pitch: 81-84cm (32–33in)

Southwest Airlines operates an open-seating policy, though passengers are boarded in three tiers (those with boarding cards "A" first, followed by "B", followed by "C"), so it pays to check-in early. EarlyBird check-in passengers will receive a reserved boarding position 36 hours prior to boarding. The fee for this is $10 per flight.

Reservations purchased online may be changed online (via the Change Air Reservation page). To change a reservation that was not made online, call 1-800-I-FLY-SWA. Southwest does not charge a fee to change a booking; passengers pay just the difference in fares.

Infants under two years of age can travel for free, if travelling on an adult's lap. Infant and child fares are not available to purchase online. Passengers are requested to call 1-800-I-FLY-SWA for details.

Available for those 65+. Prices vary from city to city. Senior airfares are fully refundable and exchangeable. Fares can be booked online or via the reservations number.

Pets (cats and dogs) may travel in the cabin with their owners (under the owner's seat). The fee is $75 (approx £46) each way.

Musical instruments can be carried on if they meet the size requirements for carry-on items. You can also purchase a seat for a large or fragile instrument at a child's fare rate, but an instrument cannot be carried in place of a free companion under any fare promotion.

Peanuts and pretzels are served free of charge, as are soft drinks. Beer, wine or cocktails are available for purchase. Satellite-enabled WiFi internet access is available onboard several flights. The fee is about $5.

Rapid Rewards allows you to earn miles when you fly Southwest. Rapid Rewards are based on the number of flights you make, rather than the miles you travel and redeemed with a number of partners, including Alamo, Budget, Hertz and Hilton.

See photographs of meals and read reviews at AirlineMeals.net.

Spirit, Southwest's in-flight magazine is available on every flight and can be read online.

Southwest Airlines has a partnership with discount Mexican airline Volaris.