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This decoder covers selected federal notices described in the book. If yours is not listed, look up the notice number on IRS.gov. Your IRS Online Account can help verify balances and certain notices; not every letter appears there.
Browse all 40 noticesOptional: notice-date and printed-deadline helper
Record dates from your notice and read the hearing-window explanation. This is an on-screen reminder, not a deadline calculator or notification service. No alerts are saved or sent.
Select a recognized notice above for the notice-specific explanation. Dates alone cannot tell us whether a hearing right applies.
Use the notice date, not the date you opened it. Changing this date clears the copied deadline so dates from different letters are not mixed.
Copy both the date and its meaning. A payment due date is not necessarily the last day to request a hearing. Dates are displayed as entered, without a time-zone shift.
No deadline has been calculated. Find the printed “last day” or “respond by” date and its label; copy it above if you want a reminder.
No universal hearing clock for every IRS notice
This helper does not assign a CDP hearing window to this notice. That does not decide whether you have appeal rights. Follow the notice-specific instructions above; an assessment response, refund review, appointment, payment demand and collection hearing can have different procedures.
Publication 1660 distinguishes Collection Due Process (CDP) from the Collection Appeals Program (CAP). CAP has its own procedures and sometimes very short action windows; it is not a substitute for a timely CDP request. Do not apply a generic 30-day rule to your letter.
Different protections. A timely CDP request generally prohibits levy for the covered periods while the proceeding and judicial review are pending, with exceptions, and suspends the collection limitation period. An equivalent hearing does not provide those levy or collection-clock protections or Tax Court review of its decision. Neither hearing request prevents a federal tax lien filing. Recording dates here or calling about payments is not a hearing request.
If the printed deadline is unclear, already passed or inconsistent with the notice, contact the IRS or a qualified representative promptly. This helper cannot determine timeliness, account-specific protections or exceptions.
Official sources checked October 30, 2026 (US Eastern)
- Publication 1660: Collection Appeal Rights (Rev. January 2020)
- Form 12153 and hearing instructions (Rev. July 2022)
- IRS Collection Due Process FAQs
- IRS CP504 instructions, including state-refund levy and earlier notices
Dates stay in this page’s memory, not in a URL or storage. Changing the notice, leaving this tool or refreshing clears these entries. Source Notes. Professional review pending.
Read the notice guides
These guides explain meanings, response instructions, official sources and next steps. You can read them without using the interactive decoder.
- CP14: Balance due (first bill)
- CP501: Reminder of balance due
- CP503: Second reminder of unpaid tax
- CP504: Notice of intent to levy
- LT11: ACS final levy warning and hearing rights
- Letter 1058: Field Collection final levy warning and hearing rights
- CP90: Federal-payment levy warning and CDP hearing rights
- Letter 3172: Federal tax lien filing and hearing rights
- Letter 725-B: Revenue officer appointment
- CP2000: Proposed income or payment mismatch adjustment
- CP508C: Seriously delinquent tax debt certified to the State Department
- CP523: Intent to terminate an installment agreement
- CP71: Annual balance reminders: CP71, CP71C and CP71D
- CP05: Your refund is being reviewed
- 5071C: Verify your identity and tax return
- CP2566: Proposed tax calculation for a missing return
- CP2566R: Proposed tax after an unanswered refund hold
- CP88: Tax refund held for missing personal tax returns
- CP49: Refund applied to tax debt
- CP63: Refund held for missing tax returns
- CP59B: Business missing-return notice — verify instructions
- CP515B: Business missing-return reminder — verify instructions
- CP518B: Final reminder to file a business tax return
- CP259: Request to file a business tax return
- CP516: Missing-return reminder — verify business instructions
- CP91: Final warning before a Social Security benefits levy
- CP298: Final warning before a Social Security benefits levy
- CP3219: Statutory notices of deficiency: CP3219 variants and Letter 3219
- CP59: Missing individual tax return
- CP515: Reminder to file an individual tax return
- CP518: Final reminder to file an individual tax return
- CP22A: Tax return changes resulted in a balance due
- CP161: Unpaid business or other tax account balance
- Letter 1277: Appeals decision on a penalty adjustment request
- Letter 4903: Verify a letter requesting a missing tax return
- CP2501: Income or payment mismatch requiring a response
- Letter 525: Audit report and general 30-day response letter
- Letter 950: 30-day letter for unagreed examination adjustments
- Letter 566: Audit request for supporting records
- Letter 1153: Proposed Trust Fund Recovery Penalty
Browse every IRS notice guide
- CP14: Balance due (first bill)
- CP501: Reminder of balance due
- CP503: Second reminder of unpaid tax
- CP504: Notice of intent to levy
- LT11: ACS final levy warning and hearing rights
- Letter 1058: Field Collection final levy warning and hearing rights
- CP90: Federal-payment levy warning and CDP hearing rights
- Letter 3172: Federal tax lien filing and hearing rights
- Letter 725-B: Revenue officer appointment
- CP2000: Proposed income or payment mismatch adjustment
- CP508C: Seriously delinquent tax debt certified to the State Department
- CP523: Intent to terminate an installment agreement
- CP71: Annual balance reminders: CP71, CP71C and CP71D
- CP05: Your refund is being reviewed
- 5071C: Verify your identity and tax return
- CP2566: Proposed tax calculation for a missing return
- CP2566R: Proposed tax after an unanswered refund hold
- CP88: Tax refund held for missing personal tax returns
- CP49: Refund applied to tax debt
- CP63: Refund held for missing tax returns
- CP59B: Business missing-return notice — verify instructions
- CP515B: Business missing-return reminder — verify instructions
- CP518B: Final reminder to file a business tax return
- CP259: Request to file a business tax return
- CP516: Missing-return reminder — verify business instructions
- CP91: Final warning before a Social Security benefits levy
- CP298: Final warning before a Social Security benefits levy
- CP3219: Statutory notices of deficiency: CP3219 variants and Letter 3219
- CP59: Missing individual tax return
- CP515: Reminder to file an individual tax return
- CP518: Final reminder to file an individual tax return
- CP22A: Tax return changes resulted in a balance due
- CP161: Unpaid business or other tax account balance
- Letter 1277: Appeals decision on a penalty adjustment request
- Letter 4903: Verify a letter requesting a missing tax return
- CP2501: Income or payment mismatch requiring a response
- Letter 525: Audit report and general 30-day response letter
- Letter 950: 30-day letter for unagreed examination adjustments
- Letter 566: Audit request for supporting records
- Letter 1153: Proposed Trust Fund Recovery Penalty