IRS Notice Deadline Calculator
Every IRS letter has a clock, and it starts on the date printed on the notice — not the day you opened it. Pick your notice below, enter that date, and see exactly how long you have and what to do with the time. Free, no signup, nothing stored.
IRS notice response windows at a glance
Standard response windows for the most common IRS notices, counted from the date printed on the letter. Each links to a plain-English guide on what the notice means and how to respond.
| Notice | What it is | Response window |
|---|---|---|
| CP2000 | Underreported Income (Proposed Changes) | 30 days |
| CP14 | Balance Due — First Notice | 21 days |
| CP504 | Notice of Intent to Levy | 30 days |
| LT11 / Letter 1058 | Final Notice of Intent to Levy | 30 days |
| CP501 / CP503 | Balance Due Reminders | 21 days |
| CP05 | Refund Hold — Return Under Review | 60 days (review window) |
| CP75 / Letter 566 | Correspondence Audit — Documents Requested | 30 days |
| CP3219A | Statutory Notice of Deficiency (90-Day Letter) | 90 days |
| CP23 | Estimated Payment Mismatch — Balance Due | 21 days |
| CP90 / CP297 | Final Notice — Intent to Levy Federal Payments | 30 days |
| CP161 | Business Balance Due | 21 days |
| CP2501 | Income Mismatch Inquiry (Pre-CP2000) | 30 days |
| CP11 | Math Error — Balance Due | 60 days |
| CP12 | Math Error — Refund Changed | 60 days |
| CP523 | Installment Agreement Default — Intent to Terminate | 30 days |
| Form 668-A | Bank / Third-Party Levy Served | 21 days |
| CP297 | Final Notice of Intent to Levy (Business) | 30 days |
| CP91 / CP298 | Final Notice Before Levy on Social Security Benefits | 30 days |
| CP22A | Changes to Your Return — Balance Due | 21 days |
| CP162 | Partnership / S-Corp Late Filing Penalty | 21 days |
| LT16 | Please Call About Your Overdue Taxes or Returns | 10 days |
| Letter 12C | Information Needed to Process Your Return | 20 days |
| Letter 2645C | We Need More Time (Interim Letter) | 60 days (review window) |
| Letter 4464C | Return Under Review Before Refund | 60 days (review window) |
| Letter 3172 | Notice of Federal Tax Lien Filed | 30 days |
Estimates based on standard windows; the specific dates and instructions printed on your notice always control. Notices not listed here (like the CP521 payment reminder or LT39) carry no single fixed deadline — see the full Notice Decoder.
Deadline questions, answered
When does the deadline on an IRS notice start counting?+
From the date printed on the notice — not the day it arrived in your mailbox and not the day you opened it. Mail delays eat into your window, which is why a notice that sat unopened for two weeks is more urgent than it looks. Always calculate from the printed date.
What happens if the deadline falls on a weekend or holiday?+
For most IRS response deadlines, a due date landing on a Saturday, Sunday, or legal holiday rolls to the next business day. But don't plan around that cushion — mail time, processing time, and the difference between 'postmarked' and 'received' make cutting it that close a bad bet.
Does mailing my response by the deadline count, or does the IRS have to receive it?+
For most IRS correspondence, a response postmarked by the deadline is treated as timely — the 'timely mailed, timely filed' rule. Use certified mail with a return receipt so you can prove the date. For anything high-stakes (a CP3219A Tax Court petition, a CDP hearing request), don't rely on the last day.
Are all IRS notice deadlines legally binding?+
They vary. Some are statutory and unforgiving — the 90-day window on a CP3219A Notice of Deficiency to petition Tax Court, and the 30-day Collection Due Process window on an LT11/CP90/CP297, generally cannot be extended. Others (like the pay-by dates on balance-due notices) are administrative: missing them triggers the next escalation letter rather than an instant loss of rights. The calculator's per-notice guide explains which kind you're holding.
What if I already missed my IRS notice deadline?+
Don't assume it's over. Depending on the notice, options often remain: audit reconsideration after a CP2000/CP3219A assessment, an 'equivalent hearing' up to one year after a missed CDP deadline, penalty abatement, payment plans at any stage, and levy releases even after garnishment starts. Every additional week narrows the menu, so act on the day you realize it's late.
Deadline coming up fast?
Free consultation — we'll read your notice, confirm the real deadline, and get the response prepared in time.