How is the U.S. income tax system structured?
During the course of a calendar year, employers are required to keep estimated taxes from their employees’ paychecks and give those dollars to the government. Sometime between January 1 and the middle of April of the following year, every individual is required to file a “tax return” with the IRS: the tax return compares the estimated amount, kept by the employer, with the actual amount of tax owed. If an employer took more in estimated taxes than what the employee actually owes, the employee will get a tax refund. If the employer withheld too little, the employee will need to pay additional taxes.