In contrast to a desktop calculator with a one-line display panel, TAC shows the Inclusive, Exclusive and Tax amount for the total and apportionment columns. At the same time TAC displays the tax type, tax rate plus the basis used for an apportionment.

TAC reduces the risk of error caused by incorrect key entry because all the figures are displayed. Unlike a desktop calculator neither the tax rate(s) nor the tax type settings need to be re-called or re-entered.

TAC system settings cover two tax years for five different countries. Tax Types, Tax Rate(s), and Tax Year settings may be changed quickly and saved, when relevant, as either Year 1 or Year 2 tax settings for 5 countries or for five user defined names.

The five-default country names may be changed to one of 160 country names listed in the calculator or to a user defined name that may relate to a State, Region, Company, Charity, Individual or special case. This powerful feature makes it easier to set the default tax types and rates to cater for different tax cases under National (Federal) and or State taxes or new tax rates planned for in a governments annual budget

TAC, which also covers basic mathematical calculations, was designed for accounting staff, auditors, business people, financial planners, investigators, lawyers and other computer users who wish to save time and have all the tax figures calculated quickly.