U.S. taxpayers who managed to file their 2012 tax returns before the April 15, 2013 deadline might have an opinion on how easy it is to access state tax rate information online. Washington D.C.-based Tax Foundation, a tax-related research body, took a look at how prominently states featured key tax data on their websites.

In March, Tax Foundation analysts started on state tax agency home pages and counted how many clicks were necessary to locate 2012 income tax rates. In Colorado, Massachusetts and Pennsylvania, site visitors could access the information in two clicks. According to the Tax Foundation, five states had the information five clicks away: Indiana, Kentucky, Minnesota, New Jersey and North Carolina.

The review also looked at whether states provided easy-to-find access tax forms, tax rates and tax tables from 2012 and 2013. Findings indicate that those data sets were accessible in only five states: Colorado, Illinois, Pennsylvania, Utah and Virginia. According to the Tax Foundation, most state revenue department sites do not yet provide tax rate information for 2013 despite the fact that 2013 income taxes are currently being withheld from taxpayer paychecks.

"Ideally, a taxpayer should be able to quickly and easily locate and understand all taxes owed and with that information make informed decisions and budgeting plans," the Tax Foundation press release reads.

As a result of high scores on its two sets of criteria, the Tax Foundation is recognizing tax agencies in Colorado, Illinois, Pennsylvania, Utah and Virginia for the transparency of their tax information, encouraging other states to follow suit.