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IRS Notices · Tax Compliance · California

IRS Notices Explained:
What Each Letter Means and What To Do

Updated: April 2025Topic: IRS Notices · Tax Compliance · California

Legal Information Notice

This guide provides general educational information about common IRS notices. It is not legal or tax advice. If you have received an IRS notice, consult a licensed tax attorney or enrolled agent before responding — especially for notices proposing additional tax, initiating collection, or requesting information under examination. Do not ignore IRS notices. Reading this does not create an attorney-client relationship.

The Golden Rule: Never Ignore an IRS Notice

The single most important thing to know about receiving an IRS notice is this: do not ignore it. Every IRS notice has a response deadline, and missing it can waive your right to appeal, result in automatic assessment of additional tax, or accelerate IRS collection action. Even if you believe the notice is wrong, the correct response is to address it — not to set it aside hoping it goes away.

The second most important thing: read the notice carefully before doing anything. Most IRS notices are about one specific issue — often something quite routine — and do not represent the catastrophic situation they initially feel like.


How to Read an IRS Notice

Every IRS notice includes a notice number (e.g., "CP2000" or "Letter 525") in the upper right corner. This number tells you exactly what type of contact it is and what the IRS expects from you. The notice also includes:


The Most Common IRS Notices California Taxpayers Receive

CP2000 — Underreporter Notice

The most common IRS notice. The IRS received information from third parties (employers, banks, brokerages, mortgage companies) that doesn't match what you reported. The CP2000 proposes additional tax based on the discrepancy. It is not a bill or an audit — it is a proposal. You have the right to agree, disagree, or partially agree. Response deadline: typically 60 days.

Common causes: Unreported 1099 income, stock sales not reported, cancelled debt income (1099-C), retirement distributions.

CP14 — Balance Due Notice

The IRS has assessed a balance due and you haven't paid it. This is typically the first notice in a collection sequence. It includes the tax owed, penalties, and interest. Interest and penalties continue to accrue. Response deadline: typically 21 days.

CP501 / CP503 — Reminder Notices

Follow-up reminders that a balance is due. These come after the CP14 if no payment or response is made. Urgency increases with each notice in the sequence.

CP504 — Intent to Levy Notice

This is serious. The CP504 is a Notice of Intent to Levy — it warns that the IRS intends to seize state tax refunds and potentially other property if the balance is not resolved. This notice is also required before the IRS can file a federal tax lien. Response deadline: 30 days before levy action can begin.

Letter 11 (LT11) — Final Notice of Intent to Levy and Right to Hearing

This is the critical notice that triggers your right to a Collection Due Process (CDP) hearing. You have 30 days from the date of this letter to request a CDP hearing. Requesting a CDP hearing suspends all levy action while the case is reviewed. Missing this 30-day window permanently waives your CDP rights for that assessment. If you receive this letter, contact a tax attorney immediately.

Letter 525 — Examination of Tax Return (Correspondence Audit)

The IRS has selected your return for examination of one or more specific items. This initiates a correspondence audit — conducted by mail, focused on specific deductions, credits, or income items. See our full IRS audit guide for how to respond.

CP05 — Identity and Refund Verification

The IRS is holding your refund while it verifies your identity and the accuracy of your return. No action is typically required unless the notice asks you to call or provide specific information. Refund delays from CP05 notices can run 60–120 days.

Letter 3172 — Notice of Federal Tax Lien Filing

The IRS has filed a Notice of Federal Tax Lien in the public records of your county. A tax lien attaches to all your property and creates a public record of the IRS claim against your assets. It can affect your ability to sell real estate, obtain credit, or conduct business. You have 5 business days from the filing to request a Collection Due Process hearing.


The Collection Notice Sequence: Understanding the Escalation

NoticeWhat It MeansUrgency
CP14First balance due noticeRespond within 21 days
CP501Second reminderIncreasing urgency
CP503Third reminderHigh — pay or respond now
CP504Intent to levy state refundsVery high — 30 days
Letter 11 / LT11Final Notice of Intent to LevyCritical — 30 days to request CDP
Lien / LevyActive collection actionEmergency — seek help immediately

When to Get Professional Help Immediately

Certain notices require professional representation before you respond: Letter 11 (Final Notice of Intent to Levy), any notice proposing a large tax assessment you dispute, any notice suggesting criminal referral or fraud penalty, and any notice following an audit that you believe is incorrect. A tax attorney can represent you at all stages, provides attorney-client privilege, and knows how to stop collection action while preserving your options.

General information. Consult a licensed tax attorney before responding to any IRS notice that proposes additional tax or initiates collection.

Common Questions

Frequently Asked Questions

What should I do immediately after receiving an IRS notice?

Read it carefully to identify the notice number, tax year, proposed amount (if any), and response deadline. Do not ignore it — every IRS notice has a deadline, and missing it can waive your rights or result in automatic assessment. For notices proposing additional tax or initiating collection action, consult a tax attorney or enrolled agent before responding. For simpler notices like CP2000, gather your documentation before responding. Never call the IRS to dispute a matter without first consulting a professional.

General information only. Consult a licensed California attorney for guidance.
Is a CP2000 notice the same as an audit?

No. A CP2000 Underreporter Notice is not a formal audit — it is the IRS comparing information it received from third parties (1099s, W-2s) against your return and proposing a change based on a discrepancy. You have the right to agree, partially agree, or disagree with the proposal. Disagreeing requires documentation supporting your original return. If the discrepancy is significant or complex, consult a tax professional before responding.

General information only. Consult a licensed California attorney for guidance.
What happens if I ignore an IRS collection notice?

Ignoring IRS collection notices escalates the situation through an increasingly serious sequence: from balance due reminders to an intent to levy notice to actual levies on bank accounts, wages, and other assets — and the filing of a federal tax lien in public records. Most significantly, you waive important rights — including Collection Due Process hearing rights — by missing response deadlines. If you cannot pay, there are IRS programs to address that; ignoring the notices removes those options over time.

General information only. Consult a licensed California attorney for guidance.

Disclaimer: All answers are for general informational purposes only and do not constitute legal or tax advice. Consult a licensed California attorney for guidance on your specific situation.

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