The interest rate that individuals will pay on underpayments remains at 3% for the first quarter of 2012. The interest rate that the IRS will pay on overpayments (tax refunds) will also be 3%. Most ordinary tax refunds do not earn interest. The IRS does not have to pay interest on tax refunds made within 45 days of the return
Eligible taxpayers may claim a tax credit for 10%, 20%, or 50% of up to $2,000 of retirement plan contributions.