Underestimating or underpaying quarterly estimated taxes usually results in IRS penalties and interest charges, even if you are due a refund when you file your annual return. The IRS (www.irs.gov/payments/underpayment-of-estimated-tax-by-individuals-penalty) applies to underpayments based on the amount, the duration of the shortfall, and current interest rates (7% for 2025/2026).
If you don't pay quarterly taxes, the IRS charges an underpayment penalty, calculated as a percentage of the unpaid tax for each month or part of a month it's late, up to 25% of the unpaid amount, plus interest, though you might avoid it if you meet a "safe harbor" (paying 90% of current liability or 100% of prior year's tax) or qualify for a penalty waiver due to disaster or other unusual circumstances.
Avoid a penalty
You may avoid the Underpayment of Estimated Tax by Individuals Penalty if: Your filed tax return shows you owe less than $1,000 or. You paid at least 90% of the tax shown on the return for the taxable year or 100% of the tax shown on the return for the prior year, whichever amount is less.
Not paying enough in estimated tax payments can mean unpleasant penalties. Luckily, in some cases you may be able to avoid paying them thanks to the estimated tax safe harbor. Safe harbor can be applied to estimated taxes giving you some leeway in how much you need to pay.
IRS underpayment penalty rate
The underpayment penalty is calculated by multiplying how much tax you owed for each quarter by the interest rate for that quarter. This quarter (January through March), the underpayment penalty interest rate is 7%, which remains the same as it was throughout 2025.
The biggest tax mistakes people make include filing late, math errors, incorrect personal info (like Social Security numbers), forgetting deductions/credits (like EITC), misreporting income, not signing forms, and making errors with bank details for direct deposit, all leading to delays, penalties, or missed savings, with using tax software or professionals helping avoid these common pitfalls.
The IRS underpayment penalty is triggered when you don't pay enough tax throughout the year, typically by failing to meet safe harbor rules: either paying less than 90% of your current year's tax liability or less than 100% (or 110% for high earners) of your prior year's tax, and owing $1,000 or more in tax after credits and withholding, or by paying estimated taxes late. Common causes include insufficient tax withholding from paychecks, underestimating income from self-employment, or not making timely quarterly estimated tax payments.
5 Common Mistakes That Lead to Employee Underpayments
This depends on your situation. The rule is that you must pay your taxes as you go throughout the year through withholding or making estimated tax payments. If at filing time, you have not paid enough income taxes through withholding or quarterly estimated payments, you may have to pay a penalty for underpayment.
Can you pay estimated taxes anytime? You don't have to wait for the deadline to submit your estimated tax payment for that quarter. When you're ready, you can make your payment to the IRS by mail, over the phone, online, or through their app. Visit IRS.gov/payments to see all your options.
The IRS $600 rule refers to a change in reporting requirements for third-party payment apps (like Venmo, PayPal) for taxable income from goods and services, where platforms must send a Form 1099-K if you receive over $600 in a year, intended to capture gig economy/side hustle income, though delays and phased implementation have adjusted the timeline, with current rules for 2024 using a higher threshold ($5,000) before fully phasing to $600 for future years, but remember all taxable income, regardless of form, must always be reported.
How do I know if I have to make quarterly individual estimated tax payments? Generally, you must make estimated tax payments for the current tax year if both of the following apply: You expect to owe at least $1,000 in tax for the current tax year after subtracting your withholding and refundable credits.
We may be able to remove or reduce some penalties if you acted in good faith and can show reasonable cause for why you weren't able to meet your tax obligations. By law we cannot remove or reduce interest unless the penalty is removed or reduced. For more information, see penalty relief.
To avoid an underpayment penalty, pay at least 90% of your current year's tax or 100% (or 110% if high-income) of your prior year's tax through withholding or estimated payments, or owe less than $1,000 at tax time; using the "Safe Harbor" rules (90%/100%/110%) is the most reliable method to ensure you don't face penalties, especially if your income fluctuates.
Use Form 2210, Underpayment of Estimated Tax by Individuals, Estates, and Trusts to see if you owe a penalty for underpaying your estimated tax.
Failure to file or pay penalties
Fires, natural disasters or civil disturbances. Inability to get records. Death, serious illness or unavoidable absence of the taxpayer or immediate family. System issues that delayed a timely electronic filing or payment.
The IRS does not check every tax return. It does not check the majority of them, but the IRS implements methods that track certain factors that would result in a further examination or audit by them.
Wages, dividends, bank interest, and other income received and that was reported on an information return should be entered carefully. This includes any information needed to calculated credits and deductions.