The number of Ohio residents charging state taxes to cards such as MasterCard, Visa, Discover or American Express is up almost 50 percent in the past three years, even though the number of people who owe money after withholding is down. The state has collected $38.1 million in card payments from 81,200 tax filers in the past five years, according to the Ohio Department of Taxation.

More than 18,500 residents used the cards to pay Ohio's income tax for 2008, a number that could grow as people granted tax extensions finish filing by the fall. The number includes debit cards, which typically make up about 10 percent of the total, said Department of Taxation spokesman John Kohlstrand.

From 2006 through this month, Franklin County residents charged almost $33 million in property taxes to plastic. This year, the average payment was $1,820, according to the county treasurer's office.

Using plastic to pay federal income taxes has mushroomed since it became legal in 1999: Last year, the Internal Revenue Service received 2.73 million payments totaling about $2.5 billion.

"It's just another option that's on the table for people to consider," said IRS spokesman Eric Erickson. "They settle up with us, and then they have to settle up with the credit-card company."

Some credit cards also provide cash back, frequent-flier miles or other benefits.

But consumer groups say it's generally not a good option unless you can afford to pay off your balance monthly.

"You're going to be paying a lot of interest on that," said Kathleen Day, a spokeswoman for the Center for Responsible Lending in Washington, D.C. "It may be better than getting a payday loan to do it, but you really should find another way."

The increasing use of credit cards to pay taxes could be a danger sign that people are becoming more financially stretched, said Kathy Virgallito of Consumer Credit Counseling in Columbus.

"You know that you're headed into some possible crisis if you're simply not having enough income" for such payments as taxes and utilities, Virgallito said.

Ohio offers the option as a convenience, and taxpayers need to decide if it's best for them, Kohlstrand said.

The average state payment was $396 for the 2008 tax year. About 2 percent of those with taxes due used a card, up from 1.5 percent the year before. The department is still processing tax extensions, and the percentage could change, Kohlstrand said. He couldn't provide the average income of people using credit cards.

Preliminary numbers for the 2008 tax year indicate that fewer federal tax filers will use plastic this year -- but fewer people also filed federal tax returns. As of June 5, about 1.87 million plastic transactions had been processed by the IRS, down about 11 percent over the same period last year. About 134 million personal income-tax returns had been filed by June 13, down about 8 percent over the same period last year, Erickson said. The IRS is still processing extensions.

The Ohio House voted this week to prohibit credit-card marketing on college campuses. Starting early next year, a new federal law will impose a host of consumer safeguards, restricting when companies can raise rates and impose certain fees.

But paying Ohio or federal taxes on a credit card will still cost you an extra 2.5 percent on top of your tax bill -- a "convenience fee" that government passes directly to the card holder.

"There's a reason they don't want to pay it," Day said. "Because they think it's too expensive."