Short Answer
An IRS notice arrives by mail with a CP (Computer Paragraph) or LTR (Letter) number on the upper right corner. The number tells you exactly what the notice is about. Common notices: CP2000 (income mismatch, ~30 days to respond), CP14 (first balance due, 21 days), LT11 (final notice of intent to levy, 30 days for CDP hearing), CP05 (refund review, no action needed), CP75 (EITC documentation request). Read the notice carefully, note the response deadline, and either agree, dispute, or request free help from the Taxpayer Advocate Service (877-777-4778) or a Low Income Taxpayer Clinic (free for income-eligible taxpayers).
Key Takeaways
- Every IRS notice has a CP or LTR number on the upper right corner of the first page. The number identifies what the notice is about. Search by that number rather than by general topic.
- Response deadlines vary: CP14 = 21 days, CP2000 = ~30 days, LT11 = 30 days for CDP hearing, CP3219A = 90 days for Tax Court petition. Missing a deadline can forfeit critical rights.
- If the notice is a refund-review notice (CP05, CP05A) you usually do not need to act. If it is a balance-due or collection notice (CP14 to LT11), action by the deadline is essential.
- Free help is available: Taxpayer Advocate Service (877-777-4778) for hardship cases; Low Income Taxpayer Clinics (250 percent of federal poverty level eligibility) for legal representation; VITA/TCE for free tax prep through community organizations.
- Real IRS notices arrive by mail with a CP/LTR number. Never demand payment by gift card, wire transfer, or crypto. If unsure, call the IRS at 800-829-1040 directly.
- Always respond in writing by certified mail with return receipt, keep copies of every document you send, and respond by the date printed on the notice (not the date you received it).
Quick Facts: Most Common IRS Notices
IRS Notice Quick Reference
| Notice | What It Means | Deadline | Urgency |
|---|
| CP14 | First balance due notice | 21 days | Medium |
| CP501 | First reminder of balance due | 21 days | Medium |
| CP503 | Second reminder of balance due | 30 days | High |
| CP504 | Final balance due, intent to seize state refund | 30 days | High |
| LT11 / L-1058 | Final notice of intent to levy + CDP rights | 30 days for CDP hearing | Critical |
| CP90 / CP297 | Final notice (older / business format) | 30 days for CDP hearing | Critical |
| CP2000 | Income mismatch with third-party reports | ~30 days | High |
| CP3219A | Statutory Notice of Deficiency (90-day letter) | 90 days for Tax Court petition | Critical |
| CP05 | Refund under review | None (wait) | Low |
| CP05A | Documentation needed for refund review | 30 days | Medium |
| CP12 | Math error correction (refund changed) | 60 days to dispute | Medium |
| CP49 | Refund applied to prior tax debt | None (informational) | Low |
| CP75 / CP75A | EITC documentation request | 30 days | High |
| CP23 | Estimated tax payment discrepancy | 30 days | Medium |
| CP59 | Unfiled return reminder | 30 days | Medium |
| LTR 4883C / 5071C | Identity verification | 30 days | High (refund held until verified) |
| LTR 525 | 30-day audit letter | 30 days to respond or 60 days to appeal | High |
| LTR 6419 | Advance Child Tax Credit reconciliation (TY 2021) | For filing reference only | Low |
Source: IRS.gov "Understanding Your IRS Notice or Letter" (irs.gov/individuals/understanding-your-irs-notice-or-letter), TAS Notices directory (taxpayeradvocate.irs.gov/notices-from-the-irs/). Deadlines are typical defaults; always read the specific date printed on your notice.
Free Help Resources
You do not have to face the IRS alone. These services are free, confidential, and either independent of the IRS or run by community organizations under federal grants. Use them.
Taxpayer Advocate Service (TAS)
Independent organization within the IRS. Helps when IRS systems fail, when an issue is causing financial hardship, or when the IRS misses promised deadlines. Free.
taxpayeradvocate.irs.gov |
877-777-4778
Low Income Taxpayer Clinics (LITCs)
Free or low-cost legal representation for taxpayers in disputes with the IRS, including audits, appeals, collection, and Tax Court. Income limit: 250% of federal poverty level.
LITC Directory |
IRS Pub 4134
VITA and TCE Programs
Volunteer Income Tax Assistance (income generally under $64K) and Tax Counseling for the Elderly (60+). Free tax preparation by IRS-certified volunteers, often at libraries and community centers.
Find a VITA/TCE site |
800-906-9887
IRS Direct Phone Line
For questions about a specific notice, scam verification, or general IRS questions. Hours: Monday to Friday, 7 a.m. to 7 p.m. local time.
Contact IRS |
800-829-1040
How to Respond to Any IRS Notice (4-Step Framework)
Step 1: Verify the Notice Is Real Confirmed
Real IRS notices arrive by U.S. Mail, include a CP or LTR number on the upper right, list the specific tax year and issue, and provide an IRS return mailing address. Real IRS notices do NOT demand payment by gift card, wire transfer, cryptocurrency, or prepaid debit card. They do NOT threaten immediate arrest or police action. If the letter feels suspicious, call 800-829-1040 directly (do not call back any number on the suspicious letter).
Step 2: Find the Deadline Confirmed
The response deadline is calculated from the date printed on the notice (not the date you receive it). Mark this date on your calendar. Common deadlines: 21 days for CP14 / CP501; 30 days for CP503, CP504, CP2000, CP75, CP05A, LT11, identity verification letters; 60 days for CP12 disputes; 90 days for CP3219A Tax Court petition.
Step 3: Decide - Agree, Dispute, or Get Help Confirmed
If you agree with the notice (you owe tax, the credit was correctly disallowed, the math error was correct), follow the payment or response instructions. If you cannot pay in full, request an installment agreement, Currently Not Collectible status, or an Offer in Compromise. If you disagree, respond in writing with copies (not originals) of supporting documents by the deadline. If the issue is complex or you need representation, contact a Low Income Taxpayer Clinic or the Taxpayer Advocate Service.
Step 4: Send Response by Certified Mail Confirmed
Always respond in writing using the address printed on the notice. Use certified mail with return receipt to prove the IRS received your response by the deadline. Keep copies of every document you send. Make a note of the date you mailed your response and keep the certified mail receipt with your tax records for the year. Email and fax responses are generally NOT accepted unless the notice specifically allows them.
The IRS Collection Notice Sequence
If you owe tax and do not pay or respond, the IRS sends an escalating series of notices. Understanding the sequence helps you act before the IRS escalates to collection action (wage garnishment, bank levy, federal payment seizure).
- CP14 (first balance due notice): Pay or respond within 21 days. The IRS adds penalty and interest from the original due date.
- CP501 (first reminder): Sent if no response to CP14. Same balance plus accrued interest. 21 days to respond.
- CP503 (second reminder): Sent if no response to CP501. Stronger language. 30 days to respond.
- CP504 (final balance due): Sent if no response to CP503. The IRS is now authorized to seize your state tax refund and certain federal payments (Social Security, vendor payments) WITHOUT further notice. 30 days to respond.
- LT11 / L-1058 (Final Notice of Intent to Levy): The CRITICAL notice. The IRS now intends to levy wages, bank accounts, retirement accounts, or other property. You have 30 days to request a Collection Due Process (CDP) hearing using Form 12153. Requesting a CDP hearing pauses the levy and preserves your right to challenge the action in Tax Court.
Each step adds penalties and interest. The earlier you respond, the more options you have. If you cannot pay, the IRS offers Online Payment Agreements (installment plans), Currently Not Collectible status (if paying causes hardship), and Offer in Compromise (settling for less than owed).
Practitioner Insight (LMN Tax Inc.)
LMN Tax Inc. - Client Pattern
At LMN Tax Inc, the most damaging client mistake on IRS notices is panic-paying or panic-ignoring. Panic-paying happens with CP2000: clients see a proposed assessment, assume the IRS is correct, and sign the response form to consent to the increase. Often the IRS missed a corresponding deduction, credit, or basis adjustment, and the client owed less than the proposed amount. Always run the numbers before signing. Panic-ignoring happens with LT11: clients put the letter in a drawer because the amount feels overwhelming, and miss the 30-day CDP hearing window. Once that window closes, Tax Court review of the levy is barred and the only remaining option is Equivalent Hearing (with much weaker rights). The third pattern is clients who try to fix CP05 by sending unsolicited documents; CP05 is a passive review and the IRS will request specific documents (CP05A) if they need them. Sending unsolicited documents can actually slow your refund. The rule of thumb: read the notice three times before acting; if anything is unclear, call TAS or an LITC before mailing a response.
Frequently Asked Questions
How do I find the CP or LTR number on my IRS notice?
The CP or LTR number is printed on the upper right corner of the first page of your IRS notice. CP stands for "Computer Paragraph" and identifies an automated notice. LTR stands for "Letter" and identifies notices that may be manually generated. Common formats: CP2000, CP14, CP501, LT11, LTR 4883C. Always look at the top right corner before searching online or calling the IRS.
How long do I have to respond to an IRS notice?
Response deadlines vary by notice type. CP14 (first balance due notice) and CP501 (first reminder) give you 21 days. CP2000 (income mismatch) typically gives 30 days. LT11 and L-1058 (Final Notice of Intent to Levy) give you 30 days to request a Collection Due Process hearing - this is a critical deadline because missing it forfeits your right to challenge the levy in Tax Court. Notice CP3219A (Statutory Notice of Deficiency) gives you 90 days to petition Tax Court (150 days if outside the U.S.). Always read the date printed on your specific notice; the deadline is calculated from that date.
What if I disagree with an IRS notice?
Follow the dispute instructions printed on your specific notice. For most notices, you must respond in writing by the deadline with copies (not originals) of supporting documents. Mail to the address shown on the notice, send via certified mail with return receipt for proof of delivery, and keep a copy of everything for your records. For CP2000 disputes, complete the response form attached to the notice and either agree, partially agree, or disagree with each line item. For collection notices (CP504, LT11), formal Collection Due Process appeal rights apply if you act by the deadline. If the dispute is complex, the Taxpayer Advocate Service (free) and Low Income Taxpayer Clinics (free for income-eligible) can help.
How do I know if an IRS letter is a scam?
Real IRS notices arrive by U.S. Mail (rarely email or text), include a CP or LTR number on the upper right corner, list the specific tax year and issue, and provide a return mailing address. Real IRS notices NEVER demand immediate payment by gift card, wire transfer, cryptocurrency, or prepaid debit card. Real IRS notices NEVER threaten immediate arrest or police action. Real IRS notices NEVER require payment without giving you the right to question or appeal. If anything feels off, call the IRS directly at 800-829-1040 to verify the notice. Do NOT call back any phone number printed on a suspicious letter; look up the IRS number independently.
What is the Taxpayer Advocate Service and how can it help me?
The Taxpayer Advocate Service (TAS) is an independent organization within the IRS that helps taxpayers when (1) IRS systems are not working as intended, (2) a tax issue is causing financial difficulty, or (3) the IRS has not responded by the date promised. TAS is FREE and confidential. Each state has at least one Local Taxpayer Advocate office. To request help, call 877-777-4778 or file Form 911 (Request for Taxpayer Advocate Service Assistance). TAS commonly helps with delayed refunds, disputed audits, levies and liens that cause hardship, identity theft cases that have stalled, and complex notice disputes.
What is a Low Income Taxpayer Clinic (LITC)?
Low Income Taxpayer Clinics (LITCs) provide free or low-cost legal representation to taxpayers in disputes with the IRS, including audits, appeals, collection cases, and Tax Court litigation. Most LITCs serve taxpayers whose income is at or below 250 percent of the federal poverty level. LITCs also help taxpayers who speak English as a second language understand their tax rights and responsibilities. To find your nearest LITC, see IRS Publication 4134 (LITC List) or visit the Taxpayer Advocate Service LITC directory. LITCs are operated by law school clinics, nonprofit organizations, and bar associations - not by the IRS.
What does CP2000 mean?
CP2000 means the IRS computer-matched your tax return against income reports submitted by third parties (employers, banks, brokerages, 1099 issuers) and found a discrepancy. The notice is NOT a bill. It is a proposed adjustment showing the income the IRS thinks you should have reported, the additional tax owed, and any interest. You have approximately 30 days from the notice date to respond. Options: (1) agree and sign the response form to consent to the assessment, (2) partially agree, or (3) disagree with documentation. CP2000 is one of the most common IRS notices and is generally not an audit, though ignoring it leads to a Statutory Notice of Deficiency (CP3219A) and eventually assessment.
What does CP14 mean?
CP14 is the IRS's first formal Notice of Tax Due and Demand for Payment. It is sent after you file a return showing tax owed but the IRS has not received payment, or after the IRS adjusts your return upward. The notice gives you 21 days to pay in full. Options if you cannot pay in full: (1) request an Online Payment Agreement (installment plan), (2) request Currently Not Collectible status if paying causes hardship, (3) submit an Offer in Compromise to settle for less, or (4) explore other relief. Ignoring CP14 leads to escalating collection notices: CP501, CP503, CP504, then LT11 (final notice of intent to levy).
What does LT11 (or L-1058) mean?
LT11 is the Final Notice of Intent to Levy and Notice of Your Right to a Hearing. This is the LAST notice you receive before the IRS can legally seize wages, bank accounts, Social Security, or other property. You have 30 days from the date on the notice to request a Collection Due Process (CDP) hearing using Form 12153. Requesting a CDP hearing pauses the levy and preserves your right to challenge the proposed action and propose collection alternatives. Missing the 30-day deadline forfeits your right to Tax Court review of the levy. If you receive an LT11 and cannot pay, contact a Low Income Taxpayer Clinic or the Taxpayer Advocate Service immediately.
What does CP05 or CP05A mean?
CP05 means the IRS is reviewing your return and verifying income, withholding, tax credits, or business income before releasing your refund. There is nothing for you to do at this point - the IRS will complete the review (typically 60 to 120 days) and either release your refund, request additional documents (CP05A), or propose changes. CP05A is a follow-up notice when the IRS needs you to send specific supporting documents (W-2, 1099, Schedule C records). Respond to CP05A within the deadline shown on the notice. Common refund-delay notices include CP05, CP05A, and CP75 (EITC documentation review).
What To Do Next
Next Step
If your notice is a balance-due or collection notice (CP14, CP501-504, LT11), and you cannot pay in full, run the IRS Payment Plan Calculator to estimate your monthly installment under the Online Payment Agreement program, plus total cost with interest and setup fees.
If your notice is a refund-related notice (CP49, CP504), check the Tax Refund Offset Calculator to see whether your refund is being applied to back taxes, child support, federal student loans, or other federal debts.
For deeper context on notice categories, response strategies, and the full collection sequence, read the paired IRS Notice Types Guide.
For status questions on a refund delayed by a notice, see IRS Still Processing: What It Means and IRS Tax Topics Explained: 152, 151, 203.
If you cannot pay and the issue is causing financial hardship, call the Taxpayer Advocate Service at 877-777-4778 (free) or find your nearest Low Income Taxpayer Clinic via IRS Publication 4134 (free for income-eligible).
Disclaimer: This tool provides educational information about common IRS notices and is not legal or tax advice. Notice meanings, deadlines, and response procedures may change as the IRS updates its procedures. Always read the specific instructions on your individual notice and follow the date printed on it. For complex disputes, consult a qualified tax professional, the Taxpayer Advocate Service, or a Low Income Taxpayer Clinic. The IRS phone number is 800-829-1040; the TAS phone number is 877-777-4778.