This write-off makes sense primarily for those who live in states that do not impose an income tax. You must choose between deducting state and local income taxes, or state and local sales taxes. For most citizens of income-tax states, the income tax deduction usually is a better deal. IRS has tables for residents of states with sales taxes showing how much they can deduct. But the tables aren’t the last word.
If you purchased a vehicle, boat or airplane, you get to add the state sales tax you paid to the amount shown in IRS tables for your state, to the extent the sales tax rate you paid doesn’t exceed the state’s general sales tax rate. The same goes for home building materials you purchased. These items are easy to overlook. The IRS even has a calculator on its Web site to help you figure out the deduction, which varies by your state and income level.