IRS LT16 Notice — Unfiled Returns Warning
What this means: LT16 is sent when the IRS believes you have unfiled tax returns. If you don't respond, the IRS can file a Substitute for Return (SFR) for you — and SFRs include no deductions, so the balance is almost always higher than if you filed correctly. You generally have 30 days.
What is an IRS LT16 notice?
IRS Letter LT16 is sent when the IRS believes you have one or more unfiled tax returns. You generally have 30 days to file or respond. If you don't, the IRS can file a Substitute for Return (SFR) on your behalf — and SFRs never include deductions or credits, so the resulting balance is almost always higher than if you had filed correctly.
Notice Type
LT16 — unfiled return warning
Based on: LT16 unfiled-return notice received
- Bank levy possible with a single letter.
- Wage garnishment is authorized.
- Asset seizure review is underway.
What This Notice Means
LT16 is a collection notice indicating the IRS believes you have one or more tax returns it has not received, or a balance it is actively pursuing. The IRS already has income data reported under your Social Security number — W-2s, 1099s, and similar forms — and it uses that data to flag the missing years. The notice is a request to file or respond before the account escalates to enforced collection.
Why You Received It
You received LT16 because the IRS's records show income for a year (or years) without a matching filed return. This is common for self-employed and 1099 workers, people who moved or changed jobs, and anyone who fell behind during a hard year. The notice does not mean you are being audited — it means the IRS wants the returns on file so it can determine the correct tax.
What Happens If Ignored
If you don't respond, the IRS can prepare a Substitute for Return using only the income reported to it. Because an SFR claims no deductions, credits, dependents, or favorable filing status, the assessed balance is almost always far higher than your true liability. That inflated balance then carries penalties and interest and feeds straight into the collection process — balance-due notices, a federal tax lien, and ultimately levies.
Deadlines That Matter
- ~30 days from the notice date — file the missing returns or respond to head off an SFR.
- If an SFR is filed — you can still file an original return to replace it and lower the balance.
- Before any resolution — all required returns must be filed; the IRS won't approve a plan or settlement otherwise.
Resolution Options
The path starts with filing, then resolving whatever balance remains:
- File the missing returns — claim your deductions and credits to set the correct, lower balance.
- Installment Agreement — pay the remaining balance over time.
- Offer in Compromise — settle for less than the full amount if you qualify.
- Penalty Abatement — request removal of failure-to-file and failure-to-pay penalties.
What happens after a federal tax lien is filed
- NOW
IRS files public notice. Credit bureaus notified. Anyone can see it.
- 30 DAYS
Penalty interest compounds daily. Balance grows automatically.
- 60 DAYS
IRS assigns a Revenue Officer. Collection action begins.
- 90 DAYS
Bank levy authority activated. IRS can freeze your account with 1 letter.
- 180+ DAYS
Wage garnishment, asset seizure, and property liens expand.
The earlier you act, the more options you have.
See What Options Apply to YouCommon Questions About LT16
What is an IRS LT16 notice?
LT16 is a notice the IRS sends when it believes you have one or more unfiled tax returns or an unpaid balance it is actively working. It asks you to file the missing returns or respond, usually within 30 days, before the account escalates.
What is a Substitute for Return (SFR)?
If you don't file, the IRS can prepare a Substitute for Return using only the income reported to it. An SFR includes no deductions, credits, dependents, or filing-status benefits, so the assessed balance is almost always far higher than if you filed the return yourself.
How long do I have to respond to LT16?
The response window is generally 30 days from the notice date. Filing the missing returns or contacting the IRS within that window is the best way to stop an SFR and keep control of the numbers.
Can I still file after the IRS files an SFR?
Yes. You can file an original return to replace the SFR, which usually lowers the balance by claiming the deductions and credits the SFR left out. A tax professional can prepare the back returns and request that the SFR assessment be adjusted.
What happens to my balance after the returns are filed?
Once your returns are filed and the correct balance is set, you can resolve it through an installment agreement, an Offer in Compromise, or Currently Not Collectible status. Getting into filing compliance is required before the IRS will approve most resolutions.
Romy Cruz, EA
Licensed Enrolled Agent
Licensed Enrolled Agent (EA) · 15 Years IRS Tax Resolution
Romy helps individuals and businesses resolve IRS tax issues including liens, levies, installment agreements, penalty relief, and offers in compromise.
Content is reviewed periodically for accuracy and updated to reflect current IRS guidance and regulations.
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