Southwest Airlines is a unique airline in the United States. While it has some markings of a traditional low-cost carrier, such as operating a single type of fleet and maintaining a single class of service, the airline also has some customer-friendly points. Here's what you need to know before your first time on Southwest.

Free checked bags and no change fees

Southwest Airlines beats network carriers in offering no change fees, as the airline allows all passengers to be flexible with their travel plans. You can change your flight as necessary to a different itinerary without paying any fees.

That being said, a fare difference may apply. Still, the carrier does not have a limit to the number of changes you can make to your flights. Considering that such administrative matters typically come at a significant cost to passengers at low-cost airlines, Southwest certainly stands out from the crowd with its policy here.

Photo: Joe Kunzler | Simple Flying

In addition, Southwest also has the most generous domestic bag policy of all major airlines, as the carrier does not charge anything for the first two checked bags that a passenger flies with. It is worth noting that size and weight limits do apply, as the bags must weigh less than 50 lbs (22.7 kg). As for the combined dimensions of these bags, they are limited to 62 inches (157.5 cm) in length+width+height.

After the first two free bags, Southwest charges $125 per bag. This does not apply to military members traveling on active duty or permanent change of station orders. Media camera bags are charged at $75 per item. There are also overweight baggage fees for non-military and non-media equipment at $100 per bag weighing 51-70 lbs (23.1-31.8 kg) and $125 per bag from 71-100 lbs (32.2-45.4 kg).

Ancillary options

There are also some ancillary purchases you can also add to your travel experience. This includes EarlyBird check-in, which starts at $15 per customer. You can also upgrade your boarding group, starting at $30 per customer per segment. Note that these fees can be as high as $25 and $80, respectively, depending on your itinerary. If you don't pay for EarlyBird, you'll have to be quick to check in 24 hours earlier to get a higher boarding number.

Photo: Markus Mainka/Shutterstock

Southwest does offer complimentary entertainment streaming through its app. WiFi access comes at $8 a day per device on a WiFi-enabled aircraft, but you will not be able to access streaming on some platforms. You can, however, take advantage of complimentary internet messaging through WhatsApp or iMessage.

No pre-assigned seating

Another aspect in which Southwest Airlines is unique is the fact that the airline does not offer pre-assigned seating. Passengers, barring those who require wheelchair assistance, are assigned a boarding group (A, B, or C) and a position (usually 1-60). Passengers then board based on their assigned group and position.

Then, once onboard, the airline has an open seating policy. Passengers choose their own seats in any available row. Note that if you want to sit in an exit row, you have to meet the requirements, such as being able to assist in the event of an emergency, being 15 years or older, and understanding English, among other policies.

Photo: Joe Kunzler | Simple Flying

All of Southwest's Boeing 737 family aircraft feature single-class seating configurations, with identical legroom everywhere except for seats in the plane's exit rows. As such, there will not be much difference between a seat in, say, row 11 versus row 20, except for being closer to the forward boarding door in the former.

For passengers who are more particular about where they would like to sit, you can, however, purchase upgraded boarding at a ticket counter into A1-A15, starting at $30, depending on your segment. This could be of interest to families who want to sit together, although the costs will quickly add up for larger groups.

Fleet and network

It's fair to say that US travelers can fly just about anywhere with Southwest in terms of the country's major cities. Operating out of bases nationwide, ch-aviation.com shows that its network comprises 4,066 routes serving 121 destinations in 12 countries. As for its fleet, the carrier has a whopping 813 Boeing 737 family jets at its disposal, with another 378 twinjets on order.

Do you have any tips for people flying Southwest for the first time? How do you rate the carrier? Let us know your thoughts and experiences in the comments!

Sources: ch-aviation.com