The tax board estimates that California is losing about $200 million a year because property owners are taking real estate deductions they are not entitled to.
The U.S. General Accounting Office says overstated real estate deductions are also contributing to the nation's tax gap. In a 2009 report, it found that taxpayers in two large counties chosen somewhat at random - Alameda and Hennepin County, Minn. - collectively overstated their deductions by somewhere between $23 million and $46 million. (Alameda accounted for about 95 percent of the overstatements.)
It acknowledged that taxpayers "face challenges determining what real-estate taxes they can deduct" because "neither local-government tax bills nor mortgage-servicer documents identify" which charges are deductible.
It recommended that the IRS change its guidance to taxpayers, revise the way it audits this deduction and find cost-effective ways the IRS and local governments could show taxpayers which charges are deductible.
"The IRS basically ignored that GAO report, they didn't do anything with it," Rodriquez says.