The advent of using the Internet to transfer documents and worldwide package delivery services has lessened the need for air couriers, but opportunities are still available for individuals seeking low-cost travel options. Courier services provide their customers with the ability to send packages more quickly than package-delivery services, because individuals give up part of their luggage space in exchange for less-expensive airfare. Luggage typically clears customs faster than packages sent on cargo planes so documents reach their recipients more quickly. Air couriers must be at least 18, and some companies have an age limit of 21.

Update your passport. You must have a valid passport to courier packages to locations outside of the United States.

Apply as a courier with air courier companies. While courier companies are not as plentiful as they were in the 1990s, some are still in operation. Typically, an air courier company will have an office at large airports, or you can contact the major airlines for information on air courier service providers.

Offer flexibility in your travel plans. You are more likely to receive offers if you are flexible in your destinations and dates.

Negotiate your travel discount. Since you are providing services using the barter system, you can negotiate your discount amount. Discounts can range from 30 to 85 percent off the regular fare for economy seats, according to MSNBC.

Read your contract carefully. If the company promises to locate a return shipment to lessen your expenses when you come back, make sure that the contract states that and provides information about what they will do if they are unable to locate a shipment.