The IRS interest rates on overpayments and underpayments for the fourth quarter of 2022 are one percentage point higher than in the third quarter (Rev. Rul. 2022-15). This is the third interest rate increase this year. The rates beginning October 1, 2022, are:
Tax paid by self-employed persons to finance Social Security coverage. In 2007, there are two rates. A 12.4% rate applies to a taxable earnings base of $95,700 or less and a 2.9% rate applies to all net earnings.