Why do airlines charge a fuel surcharge instead of raising the fares?

A fare increase by any other name…..is still more money out of pocket, right? There are a number of reasons why the airlines use a fuel surcharge instead of increasing the fare, including two financial reasons. The first is that surcharges are not taxed like fares so the airlines keep all of this money. The second has to do with the widespread use of corporate negotiated discount fares, which contractually are more difficult to increase. However, the airline can tack on a fuel surcharge without upsetting the contract, and because the fuel surcharge is not a part of the negotiated fare discount the corporation generally pays the full amount.