County auditors are already getting inquiries about the North Dakota Legislature's new tax bill, even though it doesn't take effect until the next income tax filing season. In the meantime, Tax Commissioner Cory Fong says, there's work to be done.

"We obviously have some questions, and we have some things that we need to work out," Fong said. "A lot happened with that bill in the last few hours of the session."

The bill, which was the last measure approved by the Legislature before lawmakers ended their 2007 session last week, has two major new wrinkles for North Dakotans who pay both property tax and income tax.

First, it allows them to subtract 10 percent of their property tax bills from what they owe in state income tax. The subtraction is called a property tax credit. It can be as much as $500 for an individual, and as much as $1,000 for a married couple or a business.

For example, someone who pays $2,000 in property tax and $1,000 in income tax can subtract $200 - which is 10 percent of the property tax bill - from what he or she owes in income tax, thus reducing the bill to $800.

If someone pays property tax, but does not owe income tax, the person has two options. He or she may save, or "carry forward," the credit and subtract it from future income tax bills for up to five years. Or, the person may obtain a voucher for the value of the credit, and use it to pay his or her property taxes.

A homeowner, agricultural landowner, business or any other beneficiary must pay property taxes directly to take advantage of the legislation. It does not apply to renters.

The bill's second income tax feature is a separate tax credit of up to $300 that married couples may use to offset an income tax "marriage penalty" that they may owe. The credit will be adjusted annually for inflation.

The marriage penalty describes a situation when a married couple pays more in income taxes than the couple would if he and she were single and filing separate tax returns. Whether there is a penalty depends on several factors, including the income difference between the man and woman.

The legislation requires the Tax Department to develop a worksheet, which will be included in its next income tax instruction booklet, to inform taxpayers how they may apply the credit to their own circumstances.

In Minnesota, the Legislature endorsed a marriage tax credit in 1999, and the Minnesota Department of Revenue issues instructions each year on how it is to be applied. Minnesota's maximum 2006 credit was $313. It is indexed to inflation and adjusted according to changes in state income tax law.

The North Dakota legislation gives the Tax Department authority to write administrative rules to clarify the application of the tax measure, and Fong said the task would begin soon.

"We're confident that we can make it work," Fong said. "It's a plan we can execute from an administrative perspective, but we still have lots of questions. … We're going to have to step up to the plate and do a lot of education."