Interest Rates Remaining Stable into Q1 2026
The IRS announced that for the calendar quarter beginning January 1, 2026, interest rates for overpayments and underpayments will not change from current levels. (irs.gov)
Key rates include:
- 7% per year for individual overpayments; 6% for corporations.
- 7% per year for individual underpayments.
- 9% for large corporate underpayments.
- Overpayment portions of corporate refunds exceeding $10,000 stay at the same lowered rate. (irs.gov)
Why This Matters: Practical Scenarios
| Situation | Impact | Action Example |
|---|---|---|
| You expect a refund | No rush—waiting a bit longer doesn’t escalate interest owed back to government. But don’t delay too long if filing late, as timeline still counts. | Sara mailed in her return in late December; because overpayment rates stay at 7%, she knows her refund interest won’t be penalized by increased rates just after New Year. |
| You owe taxes | Underpayment penalties won’t get more expensive in Q1 2026—though interest will accrue daily as usual. | John had a tax bill from 2025 due in early 2026; knowing rate is fixed at 7% helps budget his payment. |
| Large corporate responsibilities | Corporations facing large underpayments should still keep an eye—rate is already higher and non-individual underpayment dynamics may vary. | A corporation with $1M underpayment could incur interest at 9%; avoiding underpayments or filing extensions may help mitigate. |
Strategies to Manage Financial Exposure
- Prepay when possible: If you expect liability, paying estimated installments before due dates avoids underpayment interest.
- File returns or extensions on time: Delays can increase exposure to interest even if rates remain steady.
- For corporations: Monitor liabilities carefully, as higher underpayment rates apply.
- Review refunds: For sizable refunds, make sure tracking or bank details are correct so interest is not delayed or disrupted.
Additional Context
These interest rates are computed using the federal short-term rate plus fixed percentage points. For instance, overpayments for individuals are short-term rate +3 points; overpayments of corporations are short-term +2 (unless over $10,000) etc. The IRS publishes these rates quarterly via Revenue Rulings. (irs.gov)
Also, remember that in some cases interest rates change based on ownership type (corporate vs individual), amount owed, and whether underpayment vs overpayment.
Bottom Line
While a flat line on rates may feel like “status quo,” it gives taxpayers certainty entering 2026—key for planning payments, refunds, or avoiding surprises. If you’re expecting to owe, consult with a tax advisor; if expecting a refund, be thorough and prompt in filings, and ensure all forms reflect accurate information.