Why do I have to pay estimated tax payments?
Individuals must pay 25% of a “required annual payment” by Apr. 15, June 15, Sept. 15, and Jan. 15, to avoid an underpayment penalty. (When that date falls on a weekend or holiday, the payment is due on the next business day.) The required annual payment for most individuals is the lower of 90% of the tax shown on the current year's return or 100% of the tax shown on the return for the previous year. Certain high-income individuals must meet a more rigorous requirement. If the adjusted gross income on your previous year's return is over $150,000 (over $75,000 [...]