For many people, taxes are something that get settled once a year in April. But the U.S. tax system does not work that way. The IRS operates under a “pay-as-you-go” system, which means taxes are generally expected to be paid throughout the year as income is earned.
For individuals who receive a regular paycheck, this happens automatically through withholding. But for many investors, retirees, and self-employed individuals, income often comes from sources that do not automatically withhold taxes, such as dividends, capital gains, business income, or retirement account withdrawals. In those situations, estimated tax payments may be required.

