Interest rates charged by the Internal Revenue Service will be increasing Oct. 1.

For individuals, the rate for overpayments and underpayments will be 8% per year, compounded daily.

Other charges include:

• 8% for overpayments (payments made in excess of the amount owed), 7% for corporations.
• 5.5% for the portion of a corporate overpayment exceeding $10,000.
• 8% for underpayments (taxes owed but not fully paid).
• 10% for large corporate underpayments.

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 of a percentage point.

The IRS determined interest rates on a quarterly basis and last raised figures the first quarter of the year.