Starting Thursday, new federal rules force airlines to advertise airfares that include government taxes and mandatory fees.
Until now, airlines and travel agencies could publish fares with an asterisk, breaking out the taxes and fees in fine print.
Ticket prices may appear to rise as a result. On international journeys in particular, taxes and fees can amount to nearly 20 percent of the total cost for the flights.
Airlines, including Southwest Airlines and Spirit Airlines, have protested the new regulations. Today, Spirit Airlines took the unusual step of e-mailing its customers by email and asking them to contact their member of Congress to protest the rule change. Southwest, meanwhile, told CNN that airlines are being singled out unfairly. After all, consumers buy other goods and services without tax being disclosed upfront.
The new rule is one of several air traveler protections that come into effect this month and that are being enforced by the U.S. Department of Transportation (DOT) and championed by the Obama Administration.
For instance, starting on January 24, federal rules will ensure that passengers are able to cancel reservations, without penalty, within 24 hours of booking. Airlines will now be expected to give "prompt notification" of delays of more than half an hour, as well as any cancellations and diversions.
Looking ahead, the DOT is considering other consumer-protection measures. Among other things all airline optional fees might have to be be disclosed at the time of payment. (Currently, baggage fees aren't covered by the new regulations because those fees are optional.) The government may also act to strengthen the disclosure of codeshare flights.
SEE MORE FROM BUDGET TRAVEL: