The IRS has announced (Rev. Rul. 2013.-25) that the interest rates on tax underpayments and overpayments remain unchanged for the first quarter of 2014.
For individuals, the rate owed on underpayments to the IRS, and the rate they owe on refunds, will be 3%.
For corporations, the interest rate is 3% for underpayments (5% for “large corporate underpayments”). A For corporate overpayment amounts over $10,000, the IRS will only pay .5%.
“Large corporate underpayments” are C corporation underpayments exceeding $10,000.