Being on a tight budget, I was careful to follow the rules strictly because I knew arriving at the airport unprepared could mean extra charges.
I've mostly avoided ULCCs like Frontier and Spirit Airlines lately because of their worsening value and customer experience, but sometimes the price is just too good to pass up.
But we see people who ignore or misunderstand the a la carte business model and end up paying hundreds of dollars each time for baggage, seats, snacks, and other extras.
A recent controversy over Frontier Airlines reportedly charging customers for checked bags that fit size restrictions and then taking fees has added to the confusion.
Find out the rules for no-waste travel before you arrive at the airport
The ala carte rules for ULCCs are relatively simple: the base fare gets you a reserved seat and a personal item, but everything else (even a glass of water) costs extra.
This means that groups can only sit together if they pay for each seat, and we recommend bringing your own snacks and drinks if you don't want to pay for the expensive onboard options.
But I think what surprises first-time flyers the most is how strict the baggage size and weight restrictions are.
My backpack fits perfectly through the personal item size checkers on both Frontier and Spirit Airlines. Taylor Raines/Business Insider
Frontier and Spirit Airlines require personal items to be no larger than 18 x 14 x 8 inches and do not allow checked bags with the sum of their three dimensions exceeding 62 inches.
One important thing to note: Frontier Airlines has a checked baggage weight limit of 40 pounds, while Spirit Airlines has a limit of 50. I've seen people get stumped on this point when flying back and forth between the two airlines a lot.
Additionally, carry-on baggage limits vary slightly at 24 x 16 x 10 inches and 22 x 18 x 10 inches, respectively. These rules are listed on the airline's website and are similar for other global ULCCs such as Ryanair and Allegiant Air.
The regulations may be onerous, but baggage is a lucrative secondary revenue source for airlines: In 2023, global airlines are expected to make about $33 billion in revenue from baggage alone.
If you accidentally arrive at the airport with luggage that's too big or too heavy, your best bet is to either downsize your luggage if you have the time, or accept the loss, because the gate agent has to charge you and arguing won't change their mind.
Always book directly with the airline
Frontier and Spirit allow you to book your flight through third-party websites like Priceline and Booking.com, and while you may be able to get a lower base fare, we don't recommend this.
These websites may not allow you to add baggage when booking, misleading travelers into thinking that baggage is included, and some may charge extra for baggage.
For example, a Spirit Airlines flight from New York to Orlando in early August can be purchased on Priceline for the same price as on the airline's website, but there's a $7 “fee” for each additional bag.
A screenshot from the Priceline page showing a $7 fee and a total price of $264 including checked bags. Priceline
You can add additional bags after booking, but because of how Spirit operates, it will cost more than adding bags when booking on their website.
Another third-party website, “TravelGo,” offers the same tickets for about $10 less, but states that carry-on baggage allowances are “up to the airline” on all fares. It's not hard to imagine how inexperienced flyers looking to save a few dollars might get confused and show up with unpaid carry-on bags.
A screenshot from the TravelGo website showing carry-on baggage allowances “varies by airline.” Travel Go
In my experience, booking direct makes the process much clearer, with clear messaging that baggage, seats and other extras will cost extra unless you “bundle” them.
If you're not sure, call the airline, but don't ask them to make reservations for you, they also charge extra for reservations.
Do the math before booking a ULCC
With ULCCs, you only pay for extra baggage or seats if you absolutely need them, but once you add everything on, it may be cheaper to book with a major airline like American Airlines, Delta or United Airlines.
In my last post, I used the example of New York to Orlando to show how much ULCC fees can add up, but I found the same results on several other routes I looked at.
For example, a round-trip ticket between Denver and Seattle in August costs $187 in basic economy class on United Airlines and $267 on Delta.
If you click on the return option, a round-trip ticket on Delta will cost $267 instead of $228. Google Flights
United's fare includes a seat assignment and a personal item. For an extra $60 over regular economy class, you get a carry-on bag and a seat assignment. Delta's base fare already includes a carry-on bag but doesn't include a seat assignment. Paying extra for regular economy class with a seat will cost you $347.
The base fare for the same route on Frontier Airlines with similar departure times for both legs is $197. Add in the cheapest seat at $39 each way and a carry-on bag at $69 each way, and the total fare comes to $413.
Frontier charges will add up once you start making payments in both directions. Frontier Airlines
Another example I found was between Las Vegas and Chicago, where Spirit Airlines charges more than American Airlines if you add luggage.
Just because the cost is lower doesn't mean it's actually the lowest price. Additionally, ULCCs don't offer a better flying experience due to their lean planes and poor customer service and reliability.
Don’t resort to TikTok “hacks”
Frequent flyers and TikTok users have been testing the limits of ULCC rules for years, with many finding ways to get around size and weight rules and bring more baggage than their ticket allows.
Think of Joey from the TV show Friends: Some people show up to the airport wearing everything they can't fit in their personal belongings, or stuff their excess stuff into pillowcases.
A Business Insider reporter tested the popular hack in August 2023, which involves stuffing extra items into the pockets of a fishing vest and wearing it during a flight.
The fishing vest's back pocket can hold a BI reporter's laptop. Hannah Torway/Business Insider
The vest hack has worked for some reporters, and I've seen the pillow trick work as well, but these tactics can be risky and could cost you hundreds of dollars if you get caught.
According to a viral TikTok video posted on June 4, a gate agent at a Frontier Airlines flight in Orlando recently prevented a Buffalo-bound passenger from carrying a pillowcase full of items.
Spirit Airlines' website states that you can bring neck and head pillows as long as they fit in your personal luggage, but if you pack extra clothes, your carry-on fees could end up exceeding the cost of your flight.
