United Airlines Carry-On Baggage Rules Explained

Understanding the carry-on baggage rules before flying can save you time, money, and stress at the airport. If you’re traveling with United Airlines, knowing what you can bring onboard and what you can’t helps ensure a smooth boarding experience. This guide explains United Airlines’ carry-on baggage rules in a simple and practical way, so you can pack with confidence.

What Is Allowed as Carry-On Baggage on United Airlines?

Most United Airlines passengers are allowed to bring two items onboard:

1. One carry-on bag
   
   

2. One personal item
   
   

Your carry-on bag must fit in the overhead bin, while the personal item should fit under the seat in front of you.

Maximum carry-on bag size:

• 22 x 14 x 9 inches (including wheels and handles)
  
  

United Airlines does not publish a strict weight limit for carry-on bags, but passengers must be able to lift the bag into the overhead bin without assistance. If your bag is too large or heavy, it may be checked at the gate.

Personal Item Size and Examples

Your personal item must be smaller than your carry-on bag and fit completely under the seat. Common examples include:

• Laptop bag
  
  

• Purse or handbag
  
  

• Small backpack
  
  

• Camera bag
  
  

Travelers should avoid overpacking personal items, as oversized bags may be flagged during boarding, especially on full flights.

Basic Economy Carry-On Restrictions

United Airlines’ Basic Economy fare comes with stricter carry-on rules. If you’re flying Basic Economy on most domestic routes, you are allowed:

• One personal item only
  
  

• No full-size carry-on bag
  
  

This is an important rule many travelers overlook. If you bring a carry-on bag while traveling on Basic Economy, you may be required to check it at the gate and pay an additional fee.

Exceptions apply if you:

• Are a MileagePlus Premier member
  
  

• Hold an eligible United credit card
  
  

• Are traveling on select long-haul international routes
  
  

If none of these apply, packing light is essential.

Boarding and Carry-On Enforcement

United Airlines enforces carry-on size rules at:

• Check-in counters
  
  

• Boarding gates
  
  

• Aircraft doors
  
  

If overhead bin space fills up, gate agents may require passengers to check carry-on bags, even if they meet size limits. This often happens on busy routes or smaller aircraft.

To avoid delays, board early when possible and store your bag correctly to leave space for other passengers.

Liquids and Restricted Items

Carry-on bags must follow TSA security rules:

• Liquids must be 3.4 ounces (100 ml) or less
  
  

• All liquids must fit in one quart-size clear bag
  
  

Items not allowed in carry-on baggage include:

• Sharp objects
  
  

• Large tools
  
  

• Flammable items
  
  

• Certain lithium batteries
  
  

Power banks and spare lithium batteries must be carried in your carry-on, not checked luggage.

Special Carry-On Items

United Airlines allows certain items onboard in addition to standard carry-on rules:

• Mobility aids and assistive devices (free of charge)
  
  

• Small musical instruments (if they fit overhead or under the seat)
  
  

• Diaper bags for passengers traveling with infants
  
  

These items generally do not count toward your baggage allowance, making travel easier for families and passengers with special needs.

Tips to Avoid Carry-On Problems

• Measure your bag before leaving home
  
  

• Avoid expandable luggage when fully packed
  
  

• Pack essentials in your personal item
  
  

• Board early to secure overhead space
  
  

• Review fare rules before booking
  
  

Being prepared reduces the risk of last-minute fees or forced bag checks.

Final Thoughts

United Airlines’ carry-on baggage rules are straightforward once you understand the size limits and fare-based restrictions. The key difference lies in Basic Economy vs. standard fares, which can significantly affect what you’re allowed to bring onboard. By packing smart and knowing the rules in advance, you can enjoy a smoother airport experience and start your journey stress-free.