Income taxes are a pay as you go system. That means you pay your taxes as you earn income during the year. Either your employer withholds taxes from your pay or you pay quarterly estimated taxes on your own. If you have income that's not subject to withholding, you may need to make quarterly payments. This includes income such as self-employment income, interest, dividends, prizes and rental income. It may also include income earned from gig work or other activities where you are not an employee, such as money you earn as a for-hire driver, delivery person or other service provider. Generally, this income is taxable even if you don't receive an income statement form such as a W-2 or 1099. So, make sure you keep track of how much you earn. Go to irs.gov/payments to learn more about payment options. You can pay online, by phone or with the IRS2go mobile app. When you electronically file your tax return, you can schedule your estimated tax payments with an electronic funds withdrawal from your bank account. Other free electronic payment options include: Pay online from your bank account using IRS Direct Pay and the Electronic Federal Tax Payment System or EFTPS. You must register to use this one. You can also use a debit credit card or digital wallet option or pay with cash at one of over 26,000 participating retail stores nationwide. But, know that the provider, not the IRS, charges fees for these choices. You may also choose to pay estimated tax payments in four equal quarterly payments using Form 1040-ES and mailing it with a check to the IRS. Here's the bottom line: If you expect to owe at least $1,000 in taxes, you may need to make estimated tax payments. And, if you pay too little tax during the year, you may have to pay a penalty. So, if you have taxable income from any payer that doesn't withhold tax for you, check to see if you need to make estimated tax payments. Go to IRS.gov/payasyougo to learn if you need to set up quarterly estimated tax payments or to see if you should increase your withholding if you have an employer.