More states and localities have been raising revenue by imposing taxes on the growing number of cell phones and smart phones carried by consumers, with the taxes often hidden inside the small print on the wireless service bill.

A new study by the Tax Foundation found some states to be particularly high in taxes for mobile phone users, with Nebraska leading the way at a combined federal, state and local tax rate of 23.69 percent, or 18.64 percent on average for just the combined state and local tax rate. Other states with high combined taxes include Florida, Illinois, New York, and Washington, which all top 20 percent when combining federal, state and local charges.

Some localities are particularly taxing. Notably, Baltimore, Md., imposes a $4 per line per month tax on wireless users, on top of federal and state charges, the study noted. Nearby Montgomery County, Md., levies a $3.50 per line per month tax.

According to a recent study by KSE Partners cited by the Tax Foundation, the average U.S. wireless consumer pays taxes and fees of 16.26 percent. Of that amount, the state and local charges alone average 11.21 percent.

Figuring out which state gets to impose the tax can be a bit complicated too. The wireless service company is supposed to impose taxes on the customer based on their “place of primary use,” according to the Mobile Telecommunications Sourcing Act of 2002. The “place of primary use” is generally determined by the cell phone company based on the address provided by the subscriber, and it cannot be overruled by a state taxing authority. Therefore, a cell phone user who buys a phone out of state in one of the jurisdictions that imposes lower taxes and mainly calls friends back home will generally still need to pay taxes based on where the bill is sent.

The one bright spot is that Congress recently made it easier for business people to keep track of cell phone usage and payments. Until last fall, people who used mobile phones for business needed to keep records of how much of their bill was spent on personal calls versus business-related calls. The Small Business Jobs Act, which Congress passed last September, removed cell phones from the “listed property” category, allowing their use to be deducted without the need for the annoying record-keeping requirements.

While that could be a tax break in a way, at least on the federal side, don’t expect states and localities (much less wireless service providers) to start slashing their cell phone charges any time soon.