Missing the April 15 tax deadline can trigger daily interest and compounding penalties, increasing the total amount owed ...

For individuals, the rate for overpayments and underpayments will be 7% per year, compounded daily. For corporations, the rate for overpayments will be 6%, while the rate will be 7% for underpayments ...

The IRS charges compounding daily interest rates above 3.75% plus a 0.5% monthly failure-to-pay penalty (capping at 25% of the balance), penalties that spiral faster than payday loans at 300-400% ...