Sprint Nextel should stop charging wireless phone customers a 1 percent fee to pay the state's new business tax, Comptroller Susan Combs said Monday.

Combs, the state's chief tax collector, said in a letter to Sprint Nextel Corp. on Monday that the charge implies that the company will pay a 1 percent tax on its gross receipts. But because of deductions, businesses have to pay no more than 0.7 percent of those receipts.

"Companies are prohibited by law from collecting more from their customers than the amount of tax the company will pay," Combs said.

The company should stop collecting the tax and give the Legislature time to review the issue, Combs said. Otherwise, it risks losing the money it has collected from the fee, or the Texas attorney general could force Sprint Nextel to stop collecting it.

Sprint Nextel spokesman John Taylor said that the fee is legal and that the company plans to keep collecting it.

Taylor said the company will collect less with the fee than it will owe under the tax. In part, that's because the 1 percent fee is assessed on only some services on a bill.

Sprint calls its fee a "Texas margin fee reimbursement." But that term is inappropriate because the company will not have to start paying the tax until 2008, Combs said.

The company began charging Sprint and Nextel wireless customers the 1 percent fee this month. Users of other Sprint services, such as long distance, pay 0.6 percent.

Lawmakers passed the business tax, a new version of the corporate franchise tax, last year to help pay for a reduction in school property tax rates.

"It's not unusual for a company to collect an amount identified as a reimbursement for a tax or a fee," Combs said. "But no such reimbursement for franchise tax has ever been approved by the comptroller's office."