How Do I? Compute the state and local sales tax deduction?

Taxpayers may elect to deduct state and local general sales and use taxes in lieu of deducting state and local income taxes for 2010 and 2011. Before Congress passed the 2010 Tax Relief Act (Tax Relief, Unemployment Insurance Reauthorization and Job Creation Act of 2010), the sales tax deduction was not available for the 2010 tax year. However, the 2010 Tax Relief Act retroactively extends the sales tax deduction for 2010 and also makes it available for the 2011 tax year.

Thus, all individual taxpayers who itemize their tax deductions for 2010 and 2011 on Schedule A, Form 1040, have a choice between deducting state and local income taxes (as has always been the case for itemized deductions) or deducting state and local general sales taxes as an itemized deduction instead. The state and local sales tax deduction is particularly beneficial for those taxpayers who live in states without state income taxes (Alaska, Florida, Nevada, New Hampshire, South Dakota, Texas, Tennessee, Washington state, and Wyoming), and thus don’t benefit from the state income tax deduction.

Planning Note. The extension of the deduction for state and local general sales taxes does not impact states such as California, Illinois, and Oregon that have decoupled from the deduction, or states such as Connecticut, Michigan, or West Virginia that do not allow federal itemized deductions.

Comment. It is important to remember for taxpayers who are claiming itemized deductions on Schedule A for the 2010 tax year (thus affecting deductions for state sales tax) that due to the late passage of the 2010 Tax Relief Act, the IRS will not be able to process returns of those whose filings are delayed (Schedule A filers, among others) until February 14, 2011.

Methods for calculating the deduction
The right decision is usually made simply by determining which deduction is higher for you (if you live in a state that provides for the state income tax deduction.)

If you elect to deduct state and local sales taxes in lieu of deducting state and local income taxes, you can chose between two methods of computation:

  • The actual expense method; or
  • The IRS’s optional state sales tax tables method.

Actual expense method
Under the actual expense method, you must keep the actual sales receipts that show the sales tax paid. This may be somewhat more difficult for 2010 since the 2010 Tax Relief Act was not passed until December 2010, long after some taxpayers may have thrown most of their old sales slips for ordinary expenses into the trash. Nevertheless, collecting receipts, especially for major purchases, may prove enough to make use of the “actual expense method” instead of the IRS tables.

Some further complications. Qualifying state and local sales taxes allowed under the actual expense method include only sales taxes set at the general sales tax rate, with exceptions for food, clothing, medical supplies, and motor vehicles.

Optional state sales tax tables method
Under this method, you don’t have to keep your receipts (although keeping some receipts from motor vehicle and other specified purchases may be advantageous (see below)).

The IRS optional state sales tax tables are supposed to reflect the average state sales tax deduction paid by the average resident of your state, based on both income level and number of exemptions. Income levels on the tables for each state run from $0 to “$200,000 or more;” exemption columns go from 1 to “more than 5.”

Income for purposes of the IRS tables includes adjusted gross income, plus certain non-taxable income that increases your purchasing power. The later amounts include tax-exempt interest, veterans’ and Social Security benefits, nontaxable IRA withdrawals and the like. Since the higher the income level, the higher the table deduction amount, it is to your advantage (although it is not required) to include these in this computation.

The local sales tax computation. The IRS tables do not reflect local sales taxes. The IRS does not publish the appropriate local sales tax rates. You have to find it. Taxpayers compute their combined state and local sales tax deduction amount by:

1. (a) Dividing the local general sales tax rate by the state general sales tax rate; (b) Multiplying that figure by the amount of state general sales taxes in the IRS tables; and
2. Adding the amount of local general sales taxes (1) to the amount of state general sales taxes in the tables.

Moving during the year
The IRS Optional State Sales Tax Tables cover most states and the District of Columbia. Your legal state of residence for the year determines which table to use.

If you lived in more than one state during 2010, you must multiply the table amount for each state you lived in by a fraction, equal to the number of days you lived in each state, divided by 365. Prorating local sales taxes is also required if you moved from one locality to another in the same state.

Figuring out the new sales tax itemized deduction takes several steps. Nevertheless, the tax savings available may make it well worth your while to “do the math.” You should consult your tax advisor with questions since deduction planning can be more complicated than many think.