MADISON—The April 15th income tax deadline is looming, and if last year is any indication, close to 2.8 million Wisconsinites will file returns. They reported $121.7 billion in 2005 Wisconsin Adjusted Gross Income (WAGI) and paid $6.14 billion in state income taxes, according to a new report by the nonprofit, non-partisan Wisconsin Taxpayers Alliance (WISTAX) in the latest issue of its Focus newsletter.

The first state to tax personal income, Wisconsin counts on the individual income tax as its leading source of state revenue. Last year (fiscal 2006), collections accounted for 51.1% of all general fund revenues. Of those who filed, 2.01 million paid at least some tax.

Last tax season (2005 returns, filed in 2006), 1.13 million filers were single, 0.24 million were dependent filers, another 0.24 million were heads of household, and 1.13 million were married filing jointly. Other figures for last year showed:

• the average Wisconsin adjusted gross income was $43,972;

• on returns with taxes paid, the average tax was $2,716;

• about 30% of filers claimed dependents, and 26.1 % claimed the married couple credit;

• 8.1% used the earned income credit, and another 8.1% used the homestead property tax credit; and

• 68.2% used the property tax/rent credit.

More than half (52.2%) of filers reported an adjusted gross income of less than $30,000 on their 2005 returns. This group represented 14% of total income and paid 5.6% of income taxes. A segment of this group are filers who reported WAGI under $15,000, such as dependent earners (e.g. students), and those who reported no WAGI, but claimed the homestead credit.

In contrast, those with WAGI over $100,000 accounted for 7.6% of filers and 44.3% (or $2.44 billion) of the income taxes. Included in this group were those with incomes at or above $200,000 who represented 1.6% of filers and paid 23% of the taxes.

These figures reflect Wisconsin’s "progressive" income tax, with rates that rise with income, a standard deduction that declines as income grows, and refundable tax credits for low-income individuals.

State income tax collections fluctuate with the economy, though state officials generally count on income taxes to grow about twice as fast as inflation. From 1990 through 2009, average annual growth is estimated at 5.4%. Income taxes are expected to top $7.12 billion by fiscal 2009.