The interest rates on overpayments and underpayments are unchanged from the fourth quarter of 2019 (Rev Rul. 2019-28). The rates are:
- Noncorporate overpayments and underpayments: 5%
- Corporate overpayments: 4% generally, but 2.5% for corporate overpayments exceeding $10,000
- Corporate underpayments: 5% generally but 7% for large corporate underpayments
The 5% rate is used to figure estimated tax penalties for individuals for the first quarter of 2020 and also the first 15 days of April.