Got a Letter From the IRS? How to Read It and What to Do

Most IRS letters are routine and fixable. Find the notice code printed in the right corner, look up what it means, and note the response date printed on the letter. Then decide whether you agree, partly agree or disagree, and reply by that date. Ignoring a notice is what usually makes it worse.

Last reviewed September 23, 2026

An envelope from the Internal Revenue Service can make your stomach drop. That reaction is normal. It helps to know that most IRS letters are about ordinary things: a balance due, a mismatch with a W-2 or 1099, a math correction, or a request to confirm your identity.

This guide walks you through reading any IRS notice, working out how urgent it is, and choosing a sensible next step. If you already have the letter in front of you, the free IRS Notice Decoder will explain your specific code and count the days to your deadline.

What should I do first when I get a letter from the IRS?

Take five calm steps before you do anything else.

1. Open it and read it all the way through. The IRS says to review each notice carefully and keep it for your records. Many letters answer your first questions on page one.
2. Find the notice or letter code. The IRS says it is printed in the right corner of the letter, for example "CP2000", "CP14" or "LTR 525". The code tells you which process the letter belongs to.
3. Write down the date on the notice and the response date. Some notices count days from the notice date. Others simply print a "respond by" date. The date printed on your letter is the one that counts.
4. Check that it is really from the IRS. The IRS says it normally makes first contact by U.S. mail, and payments go to the United States Treasury, not to a person or company. Our guide Is this IRS letter real? covers the checks the IRS itself recommends.
5. Decide whether you agree. Every notice falls into one of three answers: you agree, you partly agree, or you disagree. That decision drives everything else.

Don't pay anything, call any number or sign any form until you've done these five steps. And don't throw the envelope away. For some final notices, it shows how the letter was mailed.

How do I find and read the notice code?

The IRS says you can find the CP or LTR number in the right corner of the letter. Codes start with "CP" (notice), "LTR" or "Letter", or "LT". The LT11 and LT16 letters, for example, come from the IRS Automated Collection System.

Once you have the code, look for these parts of the notice:

• Tax year or period. Make sure it matches a year you actually filed (or should have filed).
• Amount. Balance due, proposed change, or refund change. Check it against your own return and payment records.
• What the IRS wants. Pay, respond, send documents, verify your identity, or nothing at all.
• Response date. Often printed near the top or in a box labelled with the date to reply or pay by.
• Your options. Most notices explain how to agree, how to disagree, and how to set up a payment plan.

You can also view certain notices and letters in your IRS Online Account. The online account shows your balance, up to 5 years of payment history and digital copies of some notices. It's a good way to confirm a letter matches what the IRS has on file.

Which IRS notices are most common, and how serious are they?

The table below covers notices people search for most. "Severity" is RAHA Financials' own 1 to 5 rating of how urgent a notice usually is. It is not an IRS classification. Your own situation may be more or less urgent.

The decoder covers 40 notices and letters in total. You can browse them all on the IRS notice pages.

What are the main types of IRS notices?

Most notices belong to one of six families. Knowing the family tells you roughly what the IRS wants.

1. Balance due and collection. CP14, CP501, CP503, CP504, LT11 and related letters. These escalate over time if the balance isn't paid or arranged. We explain the full sequence in IRS Collection Notices Explained: CP14 to LT11.

2. Income mismatch. CP2501 and CP2000 come from the IRS matching program, which compares your return with W-2s, 1099s and similar forms. A CP2000 is a proposal, not a bill. See How to Respond to a CP2000 Notice.

3. Math errors and account adjustments. CP11, CP12, CP13 and similar notices tell you the IRS corrected something on your return. For math error notices, the Internal Revenue Manual (IRM 21.5.4.3, describing IRC 6213(b)(2)) gives 60 days from the notice date to ask the IRS to reverse the change.

4. Audits (examinations). Letter 566 asks for documents, CP75 asks you to support an Earned Income Credit claim, and Letter 525 proposes changes at the end of a mail audit.

5. Identity verification. Letter 5071C and Letter 4883C mean a return was filed with your Social Security number or ITIN and the IRS wants to confirm it was you. Nothing is processed, and no refund is sent, until you verify.

6. Informational. Notices such as CP575 (EIN confirmation) and CP05 (refund review) usually need no action from you.

How long do I have to respond to an IRS notice?

It depends on the notice. There are four patterns.

• A fixed number of days from the notice date. For example, 30 days for CP504 and for LT11 / Letter 1058.
• The date printed on the notice, with a typical window. For CP2000, IRS Tax Topic 652 says to respond within 30 days of the notice date, or 60 days if you live outside the United States. The CP2000 page itself says to reply by the date listed.
• The date printed on the notice only. For CP14, CP501 and CP503, the IRS pages say to pay by the due date on your notice without giving a day count.
• No fixed deadline. Informational notices and identity verification letters fall here, although acting promptly still matters because your return or refund may be on hold.

A few deadlines are set by law and cannot be extended. The best-known is the Tax Court petition date on a CP3219A Statutory Notice of Deficiency. The IRS says it cannot extend that date, even if you're talking with it during the 90 days.

The IRS also says that to protect your appeal rights, you should reply by the due date. If you need more time, ask before the deadline, not after. For CP2000, the IRS says you can request more time. For mail audits, the IRM describes a one-time automatic 30-day extension on a first request in most cases.

The IRS Notice Decoder shows which pattern applies to your code. If you enter the date printed on your notice, it counts the days for you.

How do I know the letter is really from the IRS?

The IRS says it normally contacts you the first time by mail delivered by the U.S. Postal Service. It also lists warning signs of a scam: the contact is unexpected, rushes you, threatens you, asks for personal or financial information, or demands payment now. The IRS says a social media direct message is never from the IRS.

To check a letter, the IRS suggests searching for its notice or letter code on IRS.gov. If the letter doesn't appear in the search, or looks suspicious, the IRS says to call 800-829-1040. You can also sign in to your IRS Online Account and compare the balance or notice there. Any payment should go to "United States Treasury" or through IRS.gov/payments.

Our step-by-step guide, Is This IRS Letter Real? How to Verify It, covers private collection agencies, in-person visits and how to report a fake.

What should I do if I disagree with the notice?

You have the right to disagree, and many notices are resolved that way. The IRS says to follow the instructions in the notice to dispute it and to include information and copies of documents for it to review.

A good dispute response has four parts:

1. The response form or page from the notice, with the "disagree" box marked where there is one.
2. A short signed statement that goes item by item: what the IRS says, what is actually true, and where the proof is.
3. Copies (never originals) of the documents that prove your point, such as corrected 1099s, bank statements or receipts.
4. Proof of when you sent it. Use the method the notice lists (upload, fax or mail), and keep a record.

Some notices come with formal appeal rights. Letter 525 lets you request an Appeals review within 30 days of the letter date. LT11 / Letter 1058 and CP90 let you request a Collection Due Process (CDP) hearing with Form 12153 within 30 days, which generally pauses levy action while the hearing is pending and keeps your right to go to Tax Court.

What if I can't pay what the IRS says I owe?

Don't let the amount stop you from responding. The IRS offers several ways forward:

• Pay what you can now to reduce interest and penalties. The IRS underpayment interest rate is 7% for the fourth quarter of 2026, compounded daily.
• Apply for a payment plan. The collection notices point to the IRS Online Payment Agreement tool or Form 9465. The IRS says that if you filed on time and have an approved payment plan, the failure-to-pay penalty drops from 0.5% to 0.25% per month while the plan is in place.
• Ask about hardship. The IRS says it may temporarily delay collection if you're facing financial hardship.
• Ask about penalty relief. First Time Abate may remove certain failure-to-file, failure-to-pay and failure-to-deposit penalties if you have a clean compliance history. The IRS says that starting in summer 2026 it is moving to an Automatic Exemption from Penalty for some returns, applied at processing. See the IRS administrative penalty relief page for who qualifies.

If your records are the reason you can't tell whether the amount is right, sorting out your books comes first. The Catch-up Bookkeeping Cost Estimator gives a quick sense of scope.

What happens if I ignore an IRS notice?

The notice doesn't go away. What happens next depends on the family:

• Balance-due notices generally move from CP14 to CP501, CP503, CP504 and then a final notice with hearing rights (LT11, Letter 1058 or CP90). Interest keeps adding up, and the IRS may file a Notice of Federal Tax Lien. After the final notice, the IRS can levy wages, bank accounts and other property.
• CP2000 generally leads to a CP3219A Statutory Notice of Deficiency. If that isn't answered or petitioned to Tax Court, the IRS assesses the tax and sends a bill.
• Audit letters move to a no-reply report and Letter 525.
• Identity verification letters leave your return and refund on hold.

The IRS failure-to-pay penalty is 0.5% of the unpaid tax per month, up to 25%. It rises to 1% per month if you don't pay within 10 days after a notice of intent to levy (IRS failure to pay penalty). These are the rules, not a threat. Acting early simply keeps more options open.

When should I get professional help with an IRS notice?

Many notices are simple enough to handle yourself, especially CP14 bills you agree with, CP05 refund reviews and CP575 confirmations. Consider getting help when:

• The notice is severity 4 or 5 in our rating, such as CP504, LT11, Letter 3172 or CP3219A.
• You disagree with a CP2000 and the income involves a business, investments, crypto or a payment app.
• The notice covers more than one year, or you have unfiled returns.
• Your books are behind, so you can't tell what the right numbers are.
• You've already missed a deadline.

RAHA Financials offers an IRS Notice Response Plan for a fixed fee, quoted before any work starts. It includes a review of your notice and account transcript, a written plan (agree, partly agree or dispute), a draft response with a list of supporting documents, and deadline tracking. Outcomes depend on your facts, and we can't promise any particular result. If your situation needs an authorized representative, we'll tell you. You can book a free consultation or read about our tax filing services.

Frequently asked questions

Do I have to reply to every IRS notice?

No. The IRS says to review each notice and keep it for your records. If the notice asks you to respond or pay, act by the due date. If it is informational, such as CP575, you usually don't need to do anything.

Where is the notice code on an IRS letter?

The IRS says the CP or LTR number is printed in the right corner of the letter. Type it into the IRS Notice Decoder exactly as printed, for example "CP2000", "CP 14" or "LTR 525".

Can I get more time to respond to an IRS notice?

Sometimes, if you ask before the deadline. For CP2000, the IRS says you can request more time. Some deadlines can't be extended, including the Tax Court petition date on a CP3219A and the Collection Due Process hearing date on an LT11.

Should I call the IRS or reply in writing?

Follow the notice. Many notices invite a call if you disagree, and some ask for a written reply with documents. When a notice gives appeal rights, send the written request it describes (such as Form 12153) so there is a record. Keep notes of any call: the date, the name or ID of the person and what was agreed.

What if I already paid?

Check your IRS Online Account first. The IRS sample CP14 says to disregard the notice if you paid in full within the last 21 days. If a payment doesn't show, send or describe your proof of payment as the notice instructs.

Will an IRS notice affect my credit score?

A notice itself doesn't. The IRS says a Notice of Federal Tax Lien is a public claim against your property and may affect your ability to get credit. Liens can follow unpaid balances, which is one reason to act at the CP14 or CP501 stage.

Is the IRS Notice Decoder connected to the IRS?

No. RAHA Financials is an independent accounting firm and is not affiliated with the IRS. The decoder uses information from IRS.gov pages, publications and the Internal Revenue Manual. It asks only for the notice code and date, and it runs in your browser.

Sources

• IRS: Understanding your IRS notice or letter
• IRS: How to know it's the IRS
• IRS: Online account for individuals
• IRS: Understanding your CP2000 series notice
• IRS: Topic no. 652, Notice of underreported income – CP2000
• IRS: Understanding your CP504 notice
• IRS: Understanding your LT11 notice or Letter 1058
• IRS: Understanding your CP3219A notice
• IRS: Letters and notices offering an appeal opportunity
• IRS: Collection Due Process (CDP) FAQs
• IRS: Failure to pay penalty
• IRS: Administrative penalty relief
• IRS: Interest rates remain the same for the fourth quarter of 2026
• IRS: Publication 594, The IRS Collection Process

This guide provides general information for educational purposes and is not tax, legal or accounting advice. Consult a qualified professional before acting.