If you’ve got a job with a regular paycheck, you’re almost certainly paying taxes. While your employer withholds the taxes you owe on your earnings / income and sends them to the federal government, there’s a lot more to do with the process to make sure you’re paying taxes appropriately.
For starters, your payroll withholding usually isn’t exactly right: The decisions you make when you set up your payroll withholding at the beginning of your employment can result in you under or excessively paying your taxes.
Further, you may be able to reduce the taxes you owe and thus, get a refund on taxes you already paid by taking certain deductions or credits provided for in the tax law. On the flip-side, you might have additional income not included in your paycheck that you’re legally required to report, and which may result in you owing more in taxes.
The result of all this is that you’re required to file a tax return every year. Through this process, it’s determined whether you owe additional taxes beyond what you’ve already paid to the federal government, or if you’re owed a refund of the taxes you’ve already paid.