# What happens if you don't file taxes

Source: https://backtaxesdesk.com/unfiled-returns/what-happens-dont-file-taxes
Publisher: Back Taxes Desk (backtaxesdesk.com), independent editorial site
Topic: Unfiled Tax Returns
Last updated: 2026-10-20

> What happens if you don't file taxes depends on whether you owe. If you owe, the IRS adds 5% of the unpaid tax each month up to 25%, with a $525 minimum once a return is over 60 days late, then may file a substitute return and collect. If you are owed a refund, there is no penalty, but you lose the money after three years.

## Key facts

- Failure-to-file penalty: 5% per month or part of a month, max 25%
- Minimum if over 60 days late: $525 or 100% of tax owed, whichever is less (returns due after 2025)
- Failure-to-pay penalty: 0.5% per month, max 25%
- Interest rate, Oct-Dec 2026: 7% a year, compounded daily
- Refund deadline: 3 years from the original due date

## What happens if you don't file taxes: the direct answer

If you owe, costs start building the day after the deadline, even though the first IRS letter may not arrive for months. The IRS charges a failure-to-file penalty for each month or part of a month the return is late, adds a separate penalty for unpaid tax, and charges interest on both. Over the following months and years, it sends letters, may prepare a return for you, and can then collect by levy or lien.

If you are owed a refund, the picture is different. There is no penalty because penalties are figured on unpaid tax, and you have zero unpaid tax. The risk is losing the refund entirely once the three-year claim window closes.

## The failure-to-file penalty and the $525 minimum

The [failure-to-file penalty](https://backtaxesdesk.com/penalties-interest/failure-to-file-penalty) is 5% of the tax unpaid by the due date for each month or part of a month the return is late, up to 25%. If you also have not paid, the 0.5% failure-to-pay penalty applies in the same months, and the filing penalty is reduced by that amount so the combined charge is 5% a month for the first five months.

Once a return is more than 60 days late, a minimum kicks in. For returns due after December 31, 2025, which includes tax year 2026 returns due April 15, 2027, the minimum is $525 or 100% of the tax owed, whichever is less.

### Worked example: $4,000 owed, filed five months late

| Charge | Monthly rate | Five-month total |
| --- | --- | --- |
| Failure-to-pay | 0.5% | $100 |
| Failure-to-file (reduced by failure-to-pay) | 4.5% | $900 |
| Combined penalties | 5.0% | $1,000 |

Penalties on a $4,000 balance after five months (interest not included)

After month five the filing penalty is maxed out, but the failure-to-pay penalty keeps adding $20 a month on that $4,000 until it reaches its own 25% cap, and daily interest continues. The IRS charges a full month even if you file or pay partway through it.

### Worked example: small balance, filed 90 days late

If you owed $300 and filed 90 days late, the percentage penalty alone would be well under $100. Because the return is more than 60 days late, the minimum applies: the lesser of $525 or 100% of the tax, so the filing penalty becomes $300.

## Losing refunds after three years

Refund claims generally must be made within three years of the return due date, and the refund is limited to tax paid in the three years before the claim. Withholding and estimated payments count as paid on the original due date, so they fall outside the lookback once three years pass.

In practice, a refund for tax year 2023 is lost if the return is not filed by April 15, 2027. Our page on [filing old tax returns](https://backtaxesdesk.com/unfiled-returns/file-old-tax-returns) lists the deadline for each recent year. The IRS will also hold a refund on a current return while it shows an older return as missing, and it tells you so with a CP63 notice.

## What happens if you don't file taxes for years

The IRS compares its W-2 and 1099 records with filed returns. For a missing year, the usual path starts with a CP59 asking you to file or explain why you did not need to, followed by reminders such as CP515, CP516 and the final CP518.

If those go unanswered, the IRS may prepare a [substitute for return](https://backtaxesdesk.com/unfiled-returns/irs-substitute-for-return) using only reported income, and send a CP2566 or a CP3219N notice of deficiency. The SFR may leave out deductions and credits you could have claimed, so the tax is often higher than a return you would have filed.

Once the tax is assessed, the regular collection process begins: bills, a possible federal tax lien, a CP504 that lets the IRS take state tax refunds, and levies on wages or bank accounts after a final notice of intent to levy. Balances that reach the seriously delinquent threshold, $66,000 for 2026, can also be certified to the State Department for passport action.

### Other effects people overlook

- A short court deadline: a CP3219N notice of deficiency gives 90 days (150 if addressed outside the US) to petition the Tax Court, and filing a late return does not extend it.
- Payment plans on hold: you must be current on filing before the IRS will approve an installment agreement.
- Penalty relief limits: First Time Abate needs three prior years filed on time, so a string of missing years usually disqualifies the later ones.

## No time limit on unfiled years

When a return is filed, the IRS generally has three years to assess more tax. When no return is filed, that clock never starts, and the tax can be assessed at any time. The IRS normally pursues only the last six years, but that is a policy, not a limit written in law. The details are on our [unfiled tax returns statute of limitations](https://backtaxesdesk.com/unfiled-returns/unfiled-tax-returns-statute-of-limitations) page.

## What if you don't file taxes because you did not have to?

If your income was below the filing threshold for your age and filing status, there is no penalty and no required return. If the IRS sends a CP59 anyway, reply with Form 15103 or a letter explaining why. It can still pay to file if tax was withheld from your pay or you qualify for refundable credits, as long as the three-year window is open.

## How to fix it

1. File the most recent missing year first if it carries a refund still inside the three-year window.
2. File any year named in an IRS notice with a deadline, especially a 90-day letter.
3. File the remaining years, going back six years unless the IRS asks for more.
4. Pay what you can, then request extra time or an installment agreement.
5. Ask for penalty relief under First Time Abate or reasonable cause.

For the full process, see our [unfiled tax returns](https://backtaxesdesk.com/unfiled-returns) guide.

## Common questions

### What happens if you don't file taxes for 3 years?

If you owe, each year collects up to 25% in filing penalties plus failure-to-pay penalties and interest, and the IRS may file substitute returns. If you are owed refunds, the oldest of the three is about to expire, since refunds must be claimed within three years of the due date.

### Is there a penalty for not filing if I am owed a refund?

No. The failure-to-file penalty is a percentage of unpaid tax, so if your withholding covered your tax, the penalty is zero. You still lose the refund if you wait more than three years.

### Will the IRS file my taxes for me?

It can. After unanswered notices, the IRS may prepare a substitute for return from W-2 and 1099 data, then send a notice of deficiency proposing the tax.

### What happens if you never filed taxes at all?

There is no statute of limitations on assessing tax for a year with no return. The IRS usually concentrates on the last six years, but it can ask for older returns.

### What happens if you don't file taxes one year but pay on time?

If your payments or withholding covered the full tax, there is no failure-to-file penalty because nothing was unpaid. You should still file, since the IRS may send notices and hold future refunds until the return is in.

### What happens if you don't file your taxes but don't owe anything?

If your withholding or payments covered all of the tax, there is no failure-to-file penalty, because that penalty is a percentage of unpaid tax, and the $525 minimum is capped at 100% of the tax owed, so it is zero as well. You can still receive IRS letters such as a CP59 if you were required to file, and any refund is lost if you wait more than three years to claim it.

## Sources

- [Failure to file penalty](https://www.irs.gov/payments/failure-to-file-penalty)
- [Failure to pay penalty](https://www.irs.gov/payments/failure-to-pay-penalty)
- [Time you can claim a credit or refund](https://www.irs.gov/filing/time-you-can-claim-a-credit-or-refund)
- [Notices for past due tax returns](https://www.irs.gov/businesses/small-businesses-self-employed/notices-for-past-due-tax-returns)
- [Filing past due tax returns](https://www.irs.gov/businesses/small-businesses-self-employed/filing-past-due-tax-returns)
- [Revocation or denial of passport for unpaid taxes](https://www.irs.gov/businesses/small-businesses-self-employed/revocation-or-denial-of-passport-in-cases-of-certain-unpaid-taxes)