Your first job isn't to fix anything — it's to understand what you're actually looking at. Most IRS letters are routine, but a handful carry hard deadlines that can cost you appeal rights, trigger collections, or accelerate enforcement if you miss them. This guide walks you through exactly what to do, step by step.
Not Every IRS Letter Is a Crisis — But Every One Has a Deadline
The IRS sends hundreds of millions of notices every year. The majority are informational: a math correction, a request to verify income, a balance due reminder. They are not automatically signs that something has gone seriously wrong.
What makes IRS correspondence genuinely dangerous isn't the letter itself — it's inaction. Every notice the IRS sends includes a specific response deadline. When that deadline passes without a response, the IRS doesn't pause to wait. It advances to the next step automatically, whether that means adding penalties, issuing a levy, or closing off your right to appeal.
The goal of this guide is simple: help you figure out what you have, what it means, and what to do next before that deadline arrives.
Step 1 — Find the Notice Number in the Upper Right Corner
Every IRS letter includes a notice or letter number printed in the upper right corner of the first page. It will begin with "CP" (for computer-generated notices) or "LT" (for letter notices), followed by a number. That code tells you exactly what category of issue the IRS is raising.
Why the Notice Number Matters
The notice number is the fastest way to understand what the IRS is communicating. Two letters that look similar on the surface — both mentioning a balance due, for example — can represent very different situations depending on where they fall in the IRS collection sequence. A CP503 is an early reminder. A CP90 is a final notice of intent to seize assets. The number tells you which one you're holding.
Where to Find It
Look at the top right corner of the first page of your letter. You'll typically see a box or label that reads "Notice" or "Letter," followed by the CP or LT number. You may also see a tax year, a notice date, and a response deadline on that same page. Write all of these down before you do anything else.
What If There's No Notice Number?
Some IRS correspondence — particularly early outreach from revenue officers or certain examination-related letters — may not follow the standard CP/LT format. If you can't locate a notice number, look for the IRS employee's name and ID number, the specific tax year referenced, and any mention of a deadline or required action. These letters still require a timely response.
Step 2 — Identify What the IRS Is Actually Asking For
Once you have the notice number, you can determine what category of issue you're dealing with. IRS notices generally fall into one of four categories: informational updates, requests for additional documentation, balance due notifications, or enforcement actions. Each category carries a different urgency level and a different appropriate response.
Below is a plain-language reference for the most common notice types. This is not an exhaustive list — the IRS uses hundreds of notice codes — but these are the ones we see most frequently and the ones that carry the most significant consequences for non-response.
Common IRS Notice Types — Plain-Language Reference
These are among the most consequential notices the IRS issues. Both represent the IRS's final warning before seizing wages, bank accounts, or other assets. They also formally trigger your Collection Due Process (CDP) rights — meaning you have 30 days from the notice date to request a hearing and pause enforcement. Missing that 30-day window forfeits your CDP rights.
CP2000 — Underreporter Notice
The IRS received income information from a third party (an employer, bank, or brokerage) that doesn't match what appeared on your return. This is not an audit — it's a proposed adjustment. You have the right to agree, partially agree, or dispute it with documentation. Non-response results in the IRS assessing the proposed amount as a tax liability.
CP503 and CP504 — Balance Due Escalation
These are sequential notices in the IRS collections process. A CP503 is a second reminder that a balance is owed. A CP504 is a notice of intent to levy your state tax refund and signals that the IRS is preparing to take enforcement action. If you've received a CP504, you are close to the enforcement stage of the collections sequence.
CP90 and LT11 — Final Notice of Intent to Levy
These are among the most consequential notices the IRS issues. Both represent the IRS's final warning before seizing wages, bank accounts, or other assets. They also formally trigger your Collection Due Process (CDP) rights — meaning you have 30 days from the notice date to request a hearing and pause enforcement. Missing that 30-day window forfeits your CDP rights.
Letter 531 (Notice of Deficiency) and Form 4549 (Examination Report)
A Notice of Deficiency means the IRS has determined that you owe additional tax and is giving you 90 days to either pay, resolve the matter, or petition the U.S. Tax Court. After 90 days, the IRS can assess and collect the deficiency without further notice. Form 4549 is the examination report that typically accompanies a completed audit — it details the proposed changes and requires a response or signature.
What to Do If Your Notice Isn't Listed Here
The notices above are among the most common, but the IRS issues hundreds of different notice types. If your notice number doesn't appear in this guide, that doesn't mean it's unimportant. Look for the response deadline on the first page of your letter, identify whether the IRS is requesting information, proposing a change, or initiating enforcement, and reach out before the deadline if you're unsure how to respond.
Step 3 — Decide Whether You Can Handle This Yourself
Some IRS letters genuinely can be resolved without professional help. Others carry enough risk — forfeited appeal rights, accelerating penalties, or enforcement actions — that handling them without representation can make the situation significantly harder to resolve.
Here's a general framework. You may be able to respond on your own if the notice is informational, requests a simple correction, or involves a straightforward payment arrangement on a balance you agree with. You should strongly consider professional representation if the notice involves a levy or seizure, an audit or examination, a proposed tax deficiency, unfiled returns, or any situation where you're unsure whether you agree with the IRS's position. One conversation is usually enough to determine which category your situation falls into.
Frequently Asked Questions About IRS Notices
What should I do first when I receive a letter from the IRS?
Find the notice number in the upper right corner of the first page and locate the response deadline. Those two pieces of information tell you what the IRS is communicating and how much time you have to respond. Don't set the letter aside — deadlines in IRS correspondence are firm, and missing them can cost you options.Does getting a letter from the IRS mean I'm being audited?
Not at all. The vast majority of IRS notices are not audit notices. Many are automated alerts about a discrepancy, a balance due reminder, or a request to verify a piece of information. Audit-related correspondence — such as a CP75 or Letter 2205 — will specifically reference an examination of your return.What happens if I ignore an IRS notice?
The IRS doesn't pause when a notice goes unanswered. Depending on the notice type, non-response can result in automatic tax assessments, additional penalties and interest, the loss of your right to appeal, or the initiation of collection enforcement including wage garnishment or bank levies. Ignoring a notice doesn't make the issue go away — it removes your ability to address it on your own terms.Can I call the IRS myself to resolve a notice?
For straightforward matters — a simple payment, a minor correction, or a request for documentation — calling the IRS directly is often a reasonable first step. For anything involving a proposed tax change, an audit, a levy notice, or a situation where you're unsure of your position, having an Enrolled Agent represent you before the IRS is the more protective approach. An EA can speak directly with the IRS on your behalf and ensure your rights are preserved throughout the process.How long do I have to respond to an IRS notice?
It depends on the notice type. Most balance due and underreporter notices allow 30 to 60 days for a response. Levy notices such as the CP90 and LT11 carry a strict 30-day window to request a Collection Due Process hearing. Notices of Deficiency allow 90 days to respond or petition Tax Court. The response deadline is printed on the first page of every IRS notice — treat it as a hard deadline.