You must pay estimated tax if both of the following apply:
- You expect to owe at least $1,000 in tax for the year, after subtracting your withholding and refundable credits.
- You expect your withholding and refundable credits to be less than the smaller of:
- 90 percent of the tax to be shown on your current year tax return.
- 100 percent of the tax shown on your prior year tax return. Your prior year tax return must cover all 12 months.
Please note that these percentages may be different if you are a farmer, fisherman or higher income taxpayer. You can find the special rules in IRS Pub 505 under the heading "Who Must Pay Estimated Tax." The IRS considers all tax withholding to have been made equally throughout the year.