IRS notice codes decoded: what CP14, CP504, LT11 and the others really mean

Quick answer: the code printed in the upper-right corner of your IRS letter (for example, CP14 or LT11) identifies the stage of the collection process you are in. Early codes are simple bills; later ones are legal warnings with strict deadlines. Reading the code correctly tells you whether you have weeks to plan or only days to act.

Receiving a letter from the IRS is stressful, but the envelope is not a verdict — it is information. Below we decode the most common notices, explain the anatomy of a letter, and lay out exactly what to do (and what to avoid) at each stage.

The most common IRS notices, decoded

These are the codes you are most likely to see, listed roughly from earliest to most urgent:

• CP14 — your first bill. This is usually the first notice: it states that you have an unpaid balance. It is serious but early; you generally have about 21 days to pay or set up an arrangement before extra penalties and interest are added.
• CP501 / CP503 — reminders. If the CP14 goes unanswered, the IRS sends reminders. CP501 is the first; CP503 is a firmer second reminder. The balance is the same, but each one moves you closer to enforced collection.
• CP504 — intent to levy your state refund. This is a notice of intent to levy: the IRS warns it can seize your state tax refund and is preparing to pursue other assets. Urgency has escalated sharply by this point.
• LT11 / Letter 1058 — final notice before levy. This is the Final Notice of Intent to Levy and Notice of Your Right to a Hearing. The IRS can levy your wages, bank accounts, or property 30 days after this letter. Critically, it also grants you the right to request a Collection Due Process (CDP) hearing — but you must do so within 30 days.
• CP90 — another final levy notice. Similar to the LT11, CP90 is a final notice of intent to levy that also carries your 30-day right to a hearing. Treat it with the same urgency.
• Letter 3172 — federal tax lien filed. This tells you the IRS has filed a public Notice of Federal Tax Lien against you, which affects your credit and property. It also includes CDP hearing rights.
• CP523 — installment agreement in default. If you had a payment plan and missed a payment, CP523 warns that the IRS intends to terminate the agreement and may resume levies.
• CP2000 — underreported income (not a bill). This is not a collection notice. It is a proposed change because income reported to the IRS (from W-2s or 1099s) does not match your return. You can agree or dispute it, but you must respond by the deadline, usually 30 days.

How to read the anatomy of a notice

No matter the code, every IRS letter has the same four pieces of information. Find them first:

1. The notice number — top-right corner (e.g., CP504). This is the single most important item; it defines everything below.
2. The tax year — which year the balance or issue belongs to.
3. The amount — the balance the IRS believes you owe, broken into tax, penalties, and interest.
4. The response deadline — the date by which you must pay, respond, or request a hearing. Missing it is what turns a manageable problem into an enforced one.

What to do when a notice arrives

Work through these steps in order as soon as the letter is in your hands:

1. Do not throw it away or ignore it. Deadlines keep running whether you open the envelope or not. Ignoring mail only accelerates enforcement.
2. Identify the code and the deadline. Match the notice number to the list above so you know whether you have weeks (CP14) or a hard 30-day legal window (LT11, CP90).
3. Verify the numbers. Request your official IRS transcript and confirm the balance is correct. Notices can reflect errors, duplicate charges, or missing payments. (See our guide on tax debt over $10,000 for how larger balances change the picture.)
4. Respond before the deadline. Depending on the code, that means paying, disputing (CP2000), setting up a plan, or requesting a CDP hearing. Silence is always the worst option.
5. Get authorized representation if levies are near. If you are already at CP504, LT11, or CP90, an Enrolled Agent or tax attorney can request holds and negotiate directly with the IRS on your behalf.

Common mistakes that make a notice worse

• Assuming it will go away. Interest and penalties keep accruing; the balance grows.
• Confusing a CP2000 with a bill. A CP2000 is a proposal you can dispute — but only if you respond in time.
• Missing the 30-day hearing window. The CDP right that comes with LT11 and CP90 disappears if you wait too long.

Illustrative example

Illustrative example (not a real client). Imagine someone who ignores a CP14, then a CP501, assuming the amount is wrong. Months later an LT11 arrives. Because they now understand the code, they recognize the 30-day deadline, request a CDP hearing in time, verify the balance against their transcript, and negotiate an installment agreement — stopping the levy before it starts.

Frequently asked questions

Where is the notice code on an IRS letter?

It is printed in the upper-right corner of the first page, usually starting with ‘CP’ or ‘LT’ followed by a number.

Which IRS notice is the most urgent?

The LT11 (Letter 1058) and CP90 are the most urgent: they are final notices of intent to levy and start a strict 30-day clock to request a hearing.

Is a CP2000 the same as owing money?

Not necessarily. A CP2000 is a proposed adjustment based on unmatched income. You can agree or dispute it, but you must respond by the stated deadline.