IRS interest rates are unchanged for the fourth quarter of 2013 (October 1, 2013, through December 31, 2013). These are the rates changed on underpayments and overpayments:
The 3% rate applies to underpayments of estimated taxes by individuals. All of these rates have held steady since October 1, 2011.
Source: Rev. Rul. 2013-16
Intangible assets that come within Section 197, such as goodwill, are amortizable over a 15-year period.