Interest Rates for the Fourth Quarter of 2015 and First Quarter of 2016

The IRS underpayment and overpayment interest rates are highly important in US tax law in general, and offshore voluntary disclosures in particular. Not only do these rates determine the interest on additional tax liability on the amended tax returns, but the same rates are sued to determine the PFIC interest rate on “excess distributions”. During the fourth quarter of 2015 and the first quarter of 2016, the IRS underpayment and overpayment interest rates will be:

three (3) percent for overpayments (two (2) percent in the case of a corporation);
three (3) percent for underpayments;
five (5) percent for large corporate underpayments; and
one-half (0.5) percent for the portion of a corporate overpayment exceeding $10,000.

Under the Internal Revenue Code (IRC), the interest rates are determined on a quarterly basis. For taxpayers other than corporations, the overpayment and underpayment rate is the federal short-term rate plus 3 percentage points.

Generally, in the case of a corporation, the underpayment rate is the federal short-term rate plus 3 percentage points and the overpayment rate is the federal short-term rate plus 2 percentage points. The rate for large corporate underpayments is the federal short-term rate plus 5 percentage points. The rate on the portion of a corporate overpayment of tax exceeding $10,000 for a taxable period is the federal short-term rate plus one-half (0.5) of a percentage point.

The rate for large corporate underpayments is the federal short-term rate plus 5 percentage points. The rate on the portion of a corporate overpayment of tax exceeding $10,000 for a taxable period is the federal short-term rate plus one-half (0.5) of a percentage point.