One example is if you paid in a large amount of estimated state tax but end up with a final state tax that is lower than the sales tax deduction your tempted to take the large income tax deduction based on est. pmts. Don’t do it. Take the sales tax deduction. Why? You’re going to have to recapture the state tax refund next year if you deduct it this year. Not so with sales tax (unless you qualify for a sales tax refund in your state.)

This year my dad had no big purchases and yet the sales tax deduction was the better way to go because of a state credit. We claimed sales tax only because I knew about it. Perhaps the full interview would have gotten me there but I might not have finished the interview before 4/17.