If you've traveled by air lately, you probably paid to check your luggage and for on-board snacks, and you may have even paid for a whole host of other things that may not have been clear before you purchased your ticket.

A new report finds airlines took in $27 billion in fees in 2012, a 20 percent jump over the year before.

"The biggest problem is not so much the fees themselves. The biggest problem is the fact that the airlines do not disclose the fees," said Charlie Leocha, director of the Consumer Travel Alliance. "It's something we've been dealing with since 2008 when American Airlines became the first to break out baggage fees and since then, the airlines haven't seen a fee that they don't like. Stopping them from charging fees is not going to be easy."

Currently there's a push for more fee transparency.

"We're trying to at least get the airlines to tell us how much these fees are going to cost us before we buy our airline tickets instead of layering them on afterward," said Leocha. "It almost makes it impossible to compare prices. The airlines have made the system so complicated that the normal person can't figure it out. We want to get the airlines to release all the data on their fees and present it on a screen for consumers to look at. It should include the airfare, plus baggage fees, plus seat reservation fees and at least start with those fees so we know what the basic cost of travel will be."

Fees are expected to get worse before they get better.

The Consumer Travel Alliance has been working with the U.S. Department of Transportation to release a mandate which would require airlines to tell passengers how much the basic cost of travel is.

"If we can punch this information into a computer once the airlines release the data, then passengers will be able to see what the full cost of travel is," said Leocha.