IRS Interest Rates for Q1 2021

The interest rates on overpayments and underpayments are unchanged from the fourth quarter of 2020 (Rev Rul. 2020-28). The rates are:

• Noncorporate overpayments and underpayments: 3%
• Corporate overpayments: 2% generally, but 0.5% for corporate overpayments exceeding $10,000
• Corporate underpayments: 3% generally but 5% for large corporate underpayments

The 3% rate is used to figure estimated tax penalties for individuals for the first quarter of 2021 and also the first 15 days of April.