• United Airlines flights take off and land daily at worldwide destinations.ICHIRO/Photodisc/Getty Images
  
  United Airlines is one of the oldest and largest air carriers in the United States. Early flights date back to the 1930s, when United flew passengers across the country while other carriers maintained local commuter routes. United Airlines merged with Continental Airlines in May 2010, operating 5,800 flights per day to 370 destinations throughout the world. United Airlines complies with the Transportation Safety Administration restrictions on luggage, but has additional policies specific to the airline regarding luggage fees.
  
  

Checked Luggage

• United Airlines allows passengers two pieces of checked luggage.travelers009 image by robert stahl from Fotolia.com
  
  United Airlines allows passengers traveling within the United States two checked bags, charging $25 for the first bag and $35 for the second bag, as of 2010. Certain passengers are exempt from these fees, including frequent flyer members of the Star Alliance or Global Services programs, and military personnel either active or on leave. Checked bags must be no larger than 62 inches and must not weigh more than 50 pounds. International travelers may check their first bag for free and will be charged $50 for a second bag if traveling to Europe or $30 for a second bag if traveling to Mexico. Customers traveling internationally are required to check bags at least 45 minutes in advance of their flight departure.
  
  

Carry-On Luggage

• A briefcase which fits under the seat is allowed as carry-on luggage.Businessman in hurry! image by Rido from Fotolia.com
  
  Carry-on luggage is permitted on all United Airlines flights. A passenger may carry with them a personal item such as a purse or laptop computer, as well as one piece of luggage measuring no more than 45 inches in total. Luggage must fit under the passenger's seat or in the overhead compartment, or may be subject to checking by flight staff. Liquids and gels must be three ounces in size or smaller and must fit within a quart-sized clear plastic bag, as per Transportation Safety Administration guidelines.
  
  

Restricted Items

• Hazardous materials like flammable liquids or solids are not allowed in luggage on United Airlines.flammable solid class4 placard image by k9dg from Fotolia.com
  
  Hazardous materials are not allowed in carry-on or checked baggage. United Airlines defines hazardous materials in accordance with TSA guidelines; they include acid, explosives, flammables and poison. Firearms are restricted from United Airlines flights in carry-on luggage but may be placed in checked luggage if they are declared at the Customer Service counter and shown to be unloaded. They must be placed in a hard-sided, locked container and must remain in that container.
  
  

Excess Luggage Fees

• Additional fees apply to overweight, oversized or excess baggage.luggages image by MLProject from Fotolia.com
  
  Additional luggage fees may be charged for an excess number of bags, oversized or overweight bags, or special items. Special items include bicycles, pets in kennels, kayaks or animal antlers. These items may travel on United Airlines as checked luggage but will be charged an additional fee of $100 per item, as of 2010. Oversized bags, which are defined as luggage larger than 62 inches, or overweight bags which are heavier than 50 pounds, will be charged $100 per bag. If an item is both oversized and overweight, the charge will apply twice and will amount to $200. If that item is also a special item, an additional $100 will be charged. Excess baggage is defined by United Airlines for general passengers as more than two bags, or for military or frequent flyer members as more than three bags. Additional bags are charged $100 per piece.