TL;DR: The IRS charges both penalties and interest on unpaid tax balances, and those charges compound daily. For most individual taxpayers, the current IRS interest rate on underpayments is the federal short-term rate plus 3 percentage points, recalculated every quarter. The longer you wait to address your balance, the more you owe, but tax debt relief options exist that can reduce or even eliminate certain penalties and interest.
By Fresh Start Initiative · Tax Relief Specialist, Fresh Start Initiative
If you have an unpaid IRS balance, it is almost certainly growing right now, even if you have not received a new notice in weeks. Many people open an IRS letter expecting to see the same number they owe from last year, only to find the total has crept up by hundreds or thousands of dollars. That is not a mistake. That is how IRS penalties and interest work.
Understanding exactly what is accruing on your account is the first step toward taking control of your situation. Once you see the math, you can make a clear-eyed decision about which tax debt relief path makes the most sense for you.
This guide breaks down every major IRS penalty and interest charge in plain language, shows you how they interact, and explains what you can do to stop the bleeding before your balance grows further out of reach.
How IRS Interest Rates Are Set
The IRS does not set its own interest rate from scratch. Instead, Congress ties it to the federal short-term rate, which is published by the IRS each quarter based on Treasury auction results. For most individual taxpayers, the underpayment interest rate equals the federal short-term rate plus 3 percentage points.
That means the rate changes up to four times per year. When the Federal Reserve raises or lowers its benchmark rate, IRS interest rates eventually follow. In recent years, rising interest rates across the economy have pushed IRS underpayment rates higher, making unpaid tax debt more expensive to carry than at almost any point in the past two decades.
Critically, IRS interest compounds daily. The IRS applies interest to your outstanding balance every single day, which means you are effectively paying interest on top of interest. A balance that looks manageable today can become a much larger burden six or twelve months from now.
The Major IRS Penalty Types and What They Cost You
Interest is only one part of what the IRS adds to your balance. Penalties are separate charges that can be just as damaging. Here are the most common ones you need to know about.
| Penalty Type | Rate | Maximum Cap | When It Applies |
|---|---|---|---|
| Failure to File | 5% of unpaid tax per month | 25% of unpaid tax | Return not filed by the due date (including extensions) |
| Failure to Pay | 0.5% of unpaid tax per month | 25% of unpaid tax | Tax not paid by the original due date |
| Combined Month (File + Pay) | 5% total per month (reduced FTP) | 25% of unpaid tax | Both penalties running in the same month |
| Accuracy-Related Penalty | 20% of underpayment | No cap | Negligence or substantial understatement of tax |
| Fraud Penalty | 75% of underpayment | No cap | Fraudulent underpayment of tax |
| Underpayment of Estimated Tax | Current underpayment rate (varies quarterly) | N/A | Insufficient quarterly estimated payments |
| Failure to Deposit (Employers) | 2% to 15% depending on how late | 15% of unpaid deposit | Payroll tax deposits not made on time |
The failure-to-file penalty is the most aggressive. At 5% per month, it can add up to 25% of your unpaid tax in just five months. If you have not filed a return and you owe taxes, filing immediately, even without full payment, stops this penalty from growing further.
The failure-to-pay penalty is smaller on its own, but it runs until your balance is paid in full, up to 25% of what you originally owed. Combined with daily compounding interest, these charges can add a significant amount to your bill over time.
How Penalties and Interest Stack Up in Practice
Let’s walk through what happens to a typical unpaid balance over time. Imagine you filed your return but could not pay the full amount owed. From day one after the deadline, the failure-to-pay penalty starts at 0.5% per month. Interest starts accruing daily at the current underpayment rate.
If you also never filed your return, the failure-to-file penalty kicks in at 5% per month (reduced by the 0.5% failure-to-pay penalty when both apply in the same month, making it 4.5% net). In five months, that alone adds 22.5% to your balance before a single dollar of interest is counted.
After the failure-to-file penalty hits its 25% cap, the failure-to-pay penalty keeps running at 0.5% per month until it also hits 25%. You could theoretically end up with a balance that is 50% higher than what you originally owed, plus ongoing daily interest on the inflated total. This is why prompt action is so important, and why exploring tax debt relief options early can save you a substantial amount of money.
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Check Your Eligibility →Can the IRS Remove or Reduce These Charges?
Yes, and this is one of the most powerful tools available to people who owe back taxes. The IRS has a process called penalty abatement, which allows qualified taxpayers to have certain penalties reduced or removed entirely. Here are the main ways it works:
- First-Time Penalty Abatement (FTA): If you have a clean compliance history for the past three years (no penalties, returns filed on time), the IRS will often remove the first penalty on your account with a simple request. No special circumstances are required.
- Reasonable Cause Abatement: If you can show that your failure to file or pay was due to circumstances beyond your control, such as a serious illness, natural disaster, or incorrect advice from a tax professional, the IRS may waive the penalty. You need to document the circumstances clearly.
- Statutory Exception: In some cases, the law itself provides a penalty exception, such as when you relied on incorrect IRS written guidance.
- Offer in Compromise (OIC): If you settle your tax debt through an Offer in Compromise, the IRS typically stops adding penalties and interest once your offer is accepted. Penalties and interest that have already accrued may also be reduced as part of the settlement.
- Currently Not Collectible (CNC) Status: If the IRS determines you cannot afford to pay anything right now, it can pause collection activity. Interest and some penalties continue to accrue, but the IRS will not actively pursue you for payment.
- Installment Agreement: Entering a formal payment plan with the IRS does not stop interest, but it does reduce the failure-to-pay penalty rate from 0.5% to 0.25% per month while the agreement is in effect.
Each of these options has its own eligibility requirements, and the IRS does not automatically apply them for you. You need to request them, often with documentation and a well-prepared case. A qualified tax professional can help you explore your tax debt relief options and identify which strategy fits your situation best.
What Happens If You Do Nothing
Ignoring an IRS balance is one of the costliest decisions a taxpayer can make. The IRS has a wide range of collection tools available, and once your account moves into active collections, the consequences become much more serious than just growing interest charges.
The IRS can file a federal tax lien, which is a public legal claim against your property that appears on your credit report and can make it difficult to sell assets or obtain financing. It can issue a levy, which means it can seize wages, bank accounts, or even property without going to court first. The IRS can also revoke or deny a passport if your tax debt reaches a certain threshold and is certified as seriously delinquent.
None of these outcomes are inevitable. The IRS genuinely prefers to work out payment arrangements, and many taxpayers qualify for programs that significantly reduce what they owe. But those programs require action. The longer you wait, the fewer options you have and the higher your balance climbs.
Free Eligibility Check
See if you qualify for tax debt relief
Take 60 seconds to find out which IRS programs you may qualify for. No obligation, no cost.
Check Your Eligibility →How to Stop IRS Penalties and Interest From Growing
The most direct way to stop IRS penalties and interest is to resolve the underlying balance. That does not always mean paying in full right now. Here are the most common approaches, ranked roughly from simplest to most involved:
- Pay in full: If you can pay the entire balance, do it. Interest and penalties stop the day your payment is processed.
- Short-term payment plan: If you can pay within 180 days, the IRS offers a no-fee short-term plan. Interest and the failure-to-pay penalty continue, but at a lower combined rate.
- Long-term installment agreement: For balances you cannot pay quickly, a monthly payment plan gives you a structured path forward. The failure-to-pay penalty drops to 0.25% per month while your plan is active.
- Offer in Compromise: If you genuinely cannot pay your full balance, you may qualify to settle for less. The IRS evaluates your income, expenses, and asset equity to determine what you can realistically pay.
- Penalty abatement request: Even if you still owe the tax, you may be able to remove some or all of the penalties that have been added to your account.
- Currently Not Collectible status: A temporary pause on collection while your financial situation improves.
You do not have to figure out which option is right for you alone. See how IRS payment plans and settlement programs work and what each one requires so you can approach the IRS with a clear plan.
Frequently Asked Questions
What is the current IRS interest rate on unpaid taxes?
The IRS sets its underpayment interest rate each quarter based on the federal short-term rate plus 3 percentage points. The rate changes quarterly, so it can shift up or down throughout the year. Because interest compounds daily, even a modest rate adds up quickly on a large unpaid balance. Check the IRS website or speak with a tax professional to confirm the current quarter’s rate.
Is IRS interest tax-deductible?
Generally, no. Interest paid on personal income taxes is considered a nondeductible personal expense under the Internal Revenue Code. However, if the tax debt relates to a business and the interest is tied to business taxes, there may be limited circumstances where a deduction is possible. You should consult a tax professional about your specific situation.
Can the IRS waive interest, not just penalties?
The IRS has very limited authority to waive interest. It can only abate interest in narrow circumstances, such as when the interest resulted from an IRS error or unreasonable delay. Penalty abatement is far more available to taxpayers. However, because penalties become part of the balance that interest accrues on, removing penalties indirectly reduces the amount of future interest you accumulate.
How do I know exactly how much I owe, including all penalties and interest?
The most reliable way is to request your tax transcripts directly from the IRS or create an online account at IRS.gov to view your current balance. These sources reflect the most up-to-date figures including accrued penalties and interest. IRS notices are often dated weeks before you receive them, so the balance shown on a letter may already be outdated.
Does setting up a payment plan stop IRS interest from accruing?
No. An installment agreement does not stop interest from accruing. However, it does reduce the failure-to-pay penalty from 0.5% per month to 0.25% per month while your plan is active and in good standing. This means your total charges grow more slowly, even though interest continues to compound daily on your remaining balance.
What is the difference between a tax lien and a tax levy?
A federal tax lien is a legal claim the IRS files against your property and assets when you have an unpaid tax debt. It does not immediately take anything from you, but it damages your credit and complicates financial transactions. A tax levy is an actual seizure of your property, wages, or bank accounts to satisfy the debt. Levies are more serious and typically happen after the IRS has issued several notices without receiving a response.
