Updated September 6, 2026. Every notice description and deadline below was checked against the IRS and California FTB pages linked in the sources on that date. Notices change; the date on your letter always controls.
If you have an IRS letter in your hand, do three things before anything else: find the notice or letter number (top or bottom right corner, e.g. CP14, CP2000, LT11), find the response date printed on it, and do not pay or sign anything until you understand what the IRS is claiming. Most notices are not audits and most are fixable; the expensive mistakes are ignoring the letter or paying a number that is wrong. This guide explains the notices we see most, what each one is actually asking, the deadlines that matter, and how California’s Franchise Tax Board letters fit in. If you would rather hand it to us, our IRS resolution service starts with reading the notice with you.
First, make sure it is really the IRS
The IRS says it normally contacts you the first time by mail delivered by the U.S. Postal Service. It does not initiate contact by text, social media or email demanding payment, and it does not ask for gift cards or wire transfers. If a call or message claims to be the IRS, hang up and check your account at IRS.gov; suspicious emails can be forwarded to [email protected]. Real notices carry a notice or letter number, your taxpayer ID (partially masked), the tax year, and a way to respond by mail or online.
How to read an IRS notice
Every notice has the same bones: the notice number and date, the tax year it concerns, what the IRS believes (a balance, a mismatch, a missing return), what it wants you to do, the date it wants it by, and how to disagree. Read the “what you need to do” section first, then the amount, then the deadline. Keep the envelope; the mailing date matters if a deadline is disputed.
The notices we see most, one by one
CP14 — you owe a balance
The IRS’s own description: “We sent you this notice because you owe money on unpaid taxes.” It is usually the first bill after a return is processed with tax due, or after a penalty is assessed. Pay by the due date printed on the notice if the number is right; if you cannot pay in full, the notice is the starting point for a payment plan (below). If the amount looks wrong, compare it with your filed return before paying — a misapplied payment or a late-payment penalty that qualifies for relief is common.
CP2000 — income on file does not match your return
Not an audit and not a bill. The IRS matched third-party forms (W-2s, 1099-NEC, 1099-K, 1099-B, 1099-R) against your return and found a difference, and it proposes a change to your tax. You reply by the date listed on the notice: agree, partly agree, or disagree with documentation. The proposed amount is frequently too high because a 1099-B was matched without your cost basis or a 1099-K reported gross receipts that were already on your Schedule C. Do not file an amended return in response; answer the notice. If you do not respond, the next letter is a CP3219A Statutory Notice of Deficiency, which gives you 90 days to petition the U.S. Tax Court and cannot be extended. Full CP2000 guide →
CP501, CP503, CP504 — the balance-due reminder sequence
These escalate. CP501 is “a reminder that you owe a balance on one of your tax accounts.” CP503 says the IRS has not heard from you and you still have an unpaid balance. CP504 is a Notice of Intent to Levy under IRC 6331(d): the IRS can seize your state income tax refund, and the notice also explains that seriously delinquent debt can lead to passport denial or revocation. Each carries its own due date on the notice. The right response at any step is the same: confirm the balance is correct, then either pay or set up a payment arrangement before the sequence reaches the next letter. What CP504 authorizes → · Payment plan options →
LT11 or Letter 1058 — final notice of intent to levy
The IRS’s wording: “We haven’t received your payment for overdue taxes. We intend to seize your property or rights to property. You must contact us immediately.” This letter gives you Collection Due Process rights — you can request a hearing with Form 12153 by the deadline printed on the letter — and it is the point where representation matters most, because a levy on a bank account or wages follows if nothing happens. Do not wait for the deadline to think about it. What LT11 / Letter 1058 means and how to request the hearing →
CP59, CP516, CP518 — the IRS has no record of your return
CP59: “We have no record that you filed your prior year personal tax return.” CP516 is the follow-up, with Form 15103 to explain why you did not file or that you already did. CP518 is the “final reminder.” If you filed within the last eight weeks, the IRS says you can disregard CP59. If you genuinely have not filed, this is the moment to get the year done: the IRS can otherwise prepare a substitute return without your deductions, and the missing-year problem often starts with books that were never finished, which is why we pair this with catch-up bookkeeping for business owners.
CP523 — your installment agreement is in default
The IRS intends to terminate your payment plan and levy. This one has a stated clock: respond no later than 30 days from the date of the notice. Missed payments, a new balance from a later return, or an unfiled return are the usual causes. Fixing the cause and asking to reinstate is usually possible if you act inside the window.
Letter 5071C or 6331C — verify your identity
The IRS received a 1040-series return under your Social Security number and wants to confirm you filed it, typically at irs.gov/verifyreturn. This is not a balance-due notice. If you did not file that return, it may be identity theft and verification is how you stop the fraudulent refund.
CP3219A — statutory notice of deficiency
The IRS describes it as neither a bill nor an audit; it is the formal notice of a proposed change in your tax, normally after a CP2000 went unanswered. You have 90 days to petition the Tax Court, and the IRS states that period cannot be extended. If you agree, sign the waiver; if you disagree, the petition deadline is the one date on this page that has no do-over.
California has its own letters
Los Angeles clients often receive an FTB letter shortly after, or instead of, an IRS one, because the two agencies share information. Three to know:
- Request for Tax Return (FTB 4600): the FTB believes you had a filing requirement. Its page says that if you do not respond within 30 days of the date on the notice, it will assess tax based on available information.
- Demand for Tax Return (FTB 4601): the follow-up; if you do not respond by the date on the notice, the FTB estimates your income and issues a Notice of Proposed Assessment.
- Notice of Proposed Assessment (FTB 5830): you have the right to protest within 60 days of the notice date.
The FTB also offers its own payment plans (individuals owing $25,000 or less, paid within 60 months, with all returns for the past five years filed, $34 setup fee). If you had an IRS adjustment, expect California to follow: federal changes generally have to be reported to the FTB.
Your options once you understand the notice
You agree. Pay, or set up a payment plan. The IRS Online Payment Agreement covers balances of $50,000 or less; short-term plans of up to 180 days have no setup fee, and long-term plans currently cost $29 to set up with direct debit or $69 without (reduced or waived for low-income taxpayers). Businesses cannot apply online and go through the phone or mail process.
You partly agree. Respond with the corrected figures and documentation for the part you dispute; a CP2000 response form has a box for exactly this.
You disagree. Respond in writing by the date on the notice with the records that show why, and keep proof of mailing. For a notice of deficiency, the Tax Court petition is the only way to preserve your position.
Penalties. Failure-to-file and failure-to-pay penalties can often be removed. For eligible original returns beginning with tax year 2025 the IRS is applying an Automatic Exemption from Penalty without a request; for earlier years, First Time Abate or reasonable-cause relief has to be asked for (see our guide to first-time penalty abatement). We build that request into every notice response where it applies.
Offers in compromise exist, carry a $205 application fee, and fit far fewer people than the advertising suggests. Be cautious with any company that promises to settle your debt for pennies before it has seen your return.
When to get representation
An Enrolled Agent, CPA or attorney can speak to the IRS for you once you sign Form 2848, Power of Attorney. Representation changes the experience in two ways: the IRS calls and letters go to your representative, and the response is built by someone who does this every week. It is worth it when the balance is large, when a levy letter (CP504, LT11) has arrived, when multiple years are unfiled, or when you simply do not want to manage the correspondence. For a single CP14 you agree with, it is usually unnecessary. If you are unsure, send us the notice and we will tell you which it is. You can also contact the Taxpayer Advocate Service, an independent organization within the IRS, when the normal process is not working.
What not to do
Do not ignore the letter; every notice in the balance-due sequence assumes you are choosing not to respond. Do not call the IRS unprepared — have the notice, your return and your records in front of you. Do not pay a tax-relief company a large upfront fee based on a phone pitch. And do not file an amended return to answer a CP2000; it delays the case rather than resolving it.
Common questions
Is this notice real?
If it arrived by mail, has a notice number and matches what you see when you log in to your IRS online account, it is real. Calls, texts and emails demanding immediate payment are not how the IRS starts contact.
What if I missed the deadline on the notice?
Respond anyway, immediately. Most notices still allow a response after the date, though your options narrow as the sequence escalates; the 90-day deficiency window is the exception.
Will I be audited?
A CP2000 is a document match, not an audit, and responding correctly usually ends it. Audits arrive as their own letter with an examiner assigned.
Can penalties be removed?
Often, yes: automatically for eligible 2025-and-later original returns under the IRS’s new automatic exemption, and on request for earlier years under First Time Abate or reasonable cause.
Do you handle FTB notices too?
Yes. Most of our clients with an IRS notice have a California letter within months, and the two responses should be coordinated.
Holding a letter you are not sure about? Send us the notice or start with a few questions on the IRS resolution page. We will tell you what it means and what the next step is.
Sources
- IRS, Understanding your IRS notice or letter (hub) — irs.gov; How to know it’s the IRS — irs.gov; Report phishing — irs.gov
- IRS notice pages: CP14, CP2000, CP501, CP503, CP504, LT11 / Letter 1058, CP59, CP516, CP518, CP523, Letter 5071C/6331C, CP3219A
- IRS, Online Payment Agreement — irs.gov; Offer in Compromise — irs.gov; Form 2848 — irs.gov; Publication 594, The IRS Collection Process — irs.gov; Publication 1, Your Rights as a Taxpayer — irs.gov; automatic penalty relief (IR-2026-83) — irs.gov
- Taxpayer Advocate Service — taxpayeradvocate.irs.gov
- California FTB letters — ftb.ca.gov; Notice of Proposed Assessment protest — ftb.ca.gov; FTB payment plans — ftb.ca.gov
Questions about how this applies to your situation? We can talk it through and point you to the right next step.