To request a waiver when you file, complete IRS Form 2210 and submit it with your tax return. With the form, attach an explanation for why you didn't pay estimated taxes in the specific time period that you're requesting a waiver for. Also attach documentation that supports your statement.

The IRS rule is that tax should be paid as the income is earned. So, if you made a lot of money in the first part of 2019, but didn't pay any taxes to the IRS until the last part of 2019, you can have a refund but still owe an underpayment penalty.

An underpayment penalty is a fine charged by the Internal Revenue Service (IRS) when taxpayers don't pay enough of their estimated taxes due during the year, don't have enough withheld from their wages during the year, or pay late.

Estimated tax requirements are different for farmers, fishermen, and certain higher income taxpayers. Publication 505, Tax Withholding and Estimated Tax, provides more information about these special estimated tax rules.

Taxpayers must generally pay at least 90% of their taxes due during the previous year to avoid an underpayment penalty. The fine can grow with the size of the shortfall. Taxpayers can consult IRS instructions for Form 2210 to determine whether they're required to report an underpayment and pay a penalty.

You won't owe an estimated tax penalty if the tax shown on your 2024 return, minus your 2024 withholding, is less than $1,000. If you're a calendar year taxpayer and you file your 2024 Form 1040 by March 3, 2025, you don't need to make an estimated tax payment if you pay all the tax you owe at that time.

If you didn't pay enough tax throughout the year, either through withholding or by making estimated tax payments, you may have to pay a penalty for underpayment of estimated tax.