Last Updated on October 15, 2022
Key Takeaways
- The number of bags you are allowed to carry on a plane depends on which airline you are flying with
- You can never bring more than one official full-size carry on suitcase on all airlines in the United States.
- Full-service airlines allow you to carry two bags on the plane but the second bag is a smaller bag technically called ”the personal item”
- The personal item can be a small underseat suitcase that is only about 20% – 25% smaller than a typical full-size carry-on suitcase
- Low-cost airlines only allow you to bring a personal item for free but you can bring a second full-size carry-on if you pay the baggage fee
While it’s the job of the TSA to regulate what you are allowed to pack inside a carry-on bag, it’s up to each airline to set the rules about the size and number of carry-on bags allowed on a plane.
There is no industry standard, how many carry-on bags allowed depends of which airline you are traveling on and sometimes which fare you purchased.
There’s an important difference between what the airlines call “carry-on luggage” versus what you or I would call a bag you carry on the plane.
Airlines use the term “carry-on luggage” very specifically. “Carry-on luggage” is the suitcase or bag that is stored in the overhead bin.
But there is another bag that you also sometimes carry on a plane as hand luggage and it’s called “the personal item”. It’s the bag that you store under the seat in front of you.
Speaking colloquially, you can carry two bags on full service airlines and one on low-cost airlines.
How Many Carry-On Bags Are Allowed On Full Service Airlines
As a general rule, you are allowed 2 to carry on two bags on full service airlines like American. Airlines, Delta, Southwest, and United.
One of the bags is called “the carry-on luggage” the other bag is called “the personal item”. I previously wrote more about the differences between carry-on bags and and personal items if you want to learn more.
There is something approaching a standard carry-on baggage size in the United States of 22 x 14 x 9 inches. Many, but not all, airlines have adopted these size restrictions. Southwest allows a larger carry-on suitcase but I don’t recommend buying a 24-inch carry-on since you’ll only be able to use it on Southwest.
On full-service airlines the description of the second bag you can carry on the plane is often a little dismissive describing it as a just a purse, briefcase, or handbag. But if you dig into the regulations you’ll find that it can actually be another small underseater suitcase or a small backpack.
With full-service airlines you can take two suitcases on a plane, just one suitcase will be a little smaller than the other.
Pilots and flight attendant often carry two bags on the plane making full use of the maximum allowed luggage dimensions and avoiding the need to bring checked luggage.
Or you could take two backpacks on a plane. Again one backpack will need to be a little smaller and go under the seat in front whereas one backpack could be stowed in the overhead bin.
How Many Carry-On Bags Are Allowed On Low Cost Airlines
Low-cost airlines like Frontier, JetBlue, and Spirit, only allow you to carry on one bag for free. The personal item bag is free but to bring a second bag on the plane you’ll need to purchase a carry-on luggage allowance.
Low-cost airlines have a different business model. They aim to keep fares as low as possible to attract customers and then later sell them extras to increase profits.
The free bag on a low-cost airline isn’t a full-size carry-on suitcase. It’s technically “the personal item” and if you want to bring full-size carry-on baggage you’ll need to pay a fee. A common size for the free personal item on a low cost airline is 18 x 14 x 8 inches.
It’s not as small as you might think:
Sometimes legacy airline brands like United sell a basic economy fare to try to compete with low-cost carriers. United Basic Economy fares also only allow you to carry one bag on to the plane.