The word is spreading among the thousands of cocktail waitresses, food servers, bartenders, busboys and bellhops who make most of their money from tips. The rank-and-file workers complain that they were not consulted on the new tip formulas.

If there really is more money in town, said Arturo Valadez, a sommelier at Mandalay Bay, it's not necessarily reaching workers' pockets.

"I'm not against paying (more) taxes, but the way they are doing it isn't necessarily the most accurate or effective," he said.

The issue is coming to a head as the IRS and Las Vegas casinos negotiate a new agreement on how much tip income workers should declare to avoid being audited by the government.

Since the early 1990s Las Vegas casinos and the IRS have agreed on how much tip income the employees should declare.

Since then, the IRS has struck similar agreements with other industries nationwide, including restaurants, hair salons and barbers. In total, tip agreements with employers have yielded billions of dollars in additional taxes for the government. Included in the voluntary participation are more than 47,000 establishments nationwide. That the agreements were born in the cash-rich casino industry is apparent in the IRS tip-reporting guide for taxpayers, which specifically mentions casino workers and features an illustration of a royal flush on its cover page.

The agreements, much like hard-won union contracts, are complex, site-specific and subject to change. Each tipped position at each participating Las Vegas casino has its own tip estimate because casinos individually negotiate rates, which differ by shift and job.

A food server in a coffee shop during the day shift, for instance, might be expected to declare $13,000 in tip income, whereas a swing-shift server in a full-service restaurant could be required to declare more than $20,000 in tip income. Employers withhold taxes on the estimated tips.

The agreements ease the paperwork burden for workers and the IRS. Workers don't have to track their tips, and the IRS doesn't spend time auditing workers.

And workers know a good deal when they see it: Many earn more in tips than the amount estimated by the IRS.

That's probably why, according to the IRS, 80 percent of Nevada's more than 100,000 tip-earning hotel workers participate in the agreement program, which is voluntary for employers and workers.

More than four years ago the casino industry fought to keep down proposed tip rates that lobbyists said would have doubled, tripled and even quadrupled workers' claimed tips. Both sides wrangled over rates in the years leading up to the three-year tip agreement reached in 2003. Hoping to capture even more unreported tips, the IRS expanded the template of the Nevada agreement to casinos nationwide.

The local tip agreements expired Dec. 31, although the old rates apply until a new agreement is reached in coming weeks.

Even though tip rates probably will go up for many Las Vegas casino workers, the alternative to participating in the tip agreement isn't all that appealing.

The IRS requires tipped workers who don't participate in the agreements to track daily tips and report the aggregate on their tax returns - and risk being audited. The IRS offers a worksheet with spaces for tips earned each day, a separate column for tips shared with others and spaces for co-workers' names.

After spending eight hours on their feet at work, most are unlikely to spend their free time logging tips on a spreadsheet.

That's why the IRS negotiated rates that might be less than actual tips yet guarantee a stream of tip taxes - up to $900 million annually in Nevada - that might otherwise go uncollected.

The American Gaming Association, which helped casinos negotiate the 2003 agreement, is involved in the latest round of discussions with the IRS.

A spokesman for Senate Majority Leader Harry Reid, D-Nev., who has assisted the industry in the negotiation process, said the IRS has agreed to phase in tip-rate increases over the three years of the new agreement rather than hit workers with a bigger tax bill all at once. The phased-in increase would extend beyond Nevada to include New Jersey, the Gulf Coast and other U.S. casino markets.

The second step of the process - determining the tip rates for each casino - has been more time consuming and contentious, with the IRS "pushing for substantial increases for certain positions," Reid spokesman Jon Summers said.

IRS, American Gaming Association and Culinary Union representatives are meeting this week to iron out a compromise.

The Culinary, which began union contract negotiations with Strip casinos two weeks ago, isn't taking any chances. The union, which represents 55,000 tip-earning workers, is proposing that employers contribute to a "defense fund" to assist employees who choose not to participate in the upcoming agreement and therefore might become subject to IRS audits.

"A coffee shop waitress on graveyard can be audited after she decides not to participate because she thinks rates are too high. We don't think that's fair," Culinary Union Secretary-Treasurer D. Taylor said. "A casino executive who gets called in for an audit and is questioned has legal representation. An individual worker should not have to take on the IRS by himself."

For now, the casinos appear to have the upper hand in this high-stakes game. The industry has threatened to chuck the program entirely - a potential tax loss in the billions for the IRS - unless the agency can agree to a smaller increase in tip rates.

"The rates (the IRS is) talking about are quite scary to folks," Taylor said.

Distributed by Scripps-McClatchy Western Service, www.scrippsnews.com.