Look up an IRS notice or letter code
Enter a CP, LT, or Letter number to see what the notice generally means and what to check first. The free IRS notice lookup covers 11 reviewed codes, links to the IRS page for each one, and does not require your tax ID or a copy of your letter. Your actual notice controls dates and next steps.
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Enter your notice code
Find the CP, LT, or Letter number near the upper right of your IRS correspondence. Type that code below. You can also search a topic such as “balance due” or “refund.”
Only enter the code or a topic. Do not type your name, tax ID, amount owed, bank details, or the full letter. Search stays in your browser.
Browse official-source summaries
Common IRS notices and letters
Select a code or search above
Collection action
Notice of intent to levy for an unpaid balance
The IRS says it has not received payment for an unpaid tax balance and intends to take collection action. CP504 is an intent-to-levy notice; read the exact notice for the assets and rights involved.
Meaning and next stepsRefund or review
Refund direct-deposit information needs attention
The IRS may send CP53E when a refund is due but bank information is missing, invalid, or rejected. The notice explains how to update deposit details or request an available exception.
Meaning and next stepsBalance due
Initial balance-due notice
CP14 tells you that the IRS shows unpaid taxes on your account. It states the amount, tax year, payment due date, and ways to pay or discuss the balance.
Meaning and next stepsProposed change
Proposed tax change after an income or payment mismatch
The IRS found that information from an employer, bank, or other payer does not match your filed return. A CP2000 proposes a change; the IRS says it is not a bill.
Meaning and next stepsBalance due
Reminder about an unpaid tax balance
CP501 reminds you that the IRS still shows a balance after an earlier request for payment or response.
Meaning and next stepsBalance due
Further reminder of an unpaid tax balance
The IRS sends CP503 when it has not received payment or a response and still shows a balance on a tax account.
Meaning and next stepsIdentity verification
Verify your identity and tax return
The IRS CP5071 series, including Letter 5071C, asks you to verify your identity and whether you filed the return identified in the letter.
Meaning and next stepsInformation request
More information needed to process a return
Letter 12C asks for missing or corrected information before the IRS can finish processing an individual income tax return.
Meaning and next stepsRefund or review
Return or refund under review
The IRS needs more time to verify income, withholding, credits, or business income reported on a return.
Meaning and next stepsProposed change
Statutory notice of deficiency and Tax Court rights
The IRS proposes an adjustment and explains your right to challenge it in U.S. Tax Court. This is a rights-sensitive notice, even though it is not a bill.
Meaning and next stepsCollection action
Final intent-to-levy notice with hearing information
LT11 or Letter 1058 says the IRS has not received payment for overdue taxes and intends to levy property or rights to property.
Meaning and next stepsNeed help with your specific notice?
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IntegraFin can discuss scope after seeing the actual issue. Using this finder does not start an engagement or change an IRS deadline.
Before you respond
What to do when you get an IRS notice
Find the code, read every page, confirm the tax year and date, and compare the notice with your return and payment records. If the letter requests a response, follow its specific instructions by the stated date. A code lookup helps you orient yourself; it cannot tell whether the IRS amount is right or whether a message is authentic.
Identify the letter
Use the CP, LT, or Letter number, not a Social Security number or a long document ID.
Check the actual request
Note the year, amount, reply date, requested documents, and any appeal instructions.
Verify with the IRS
Open the linked IRS explanation and use contact details from your own notice or IRS.gov.
For help with a specific case in Katy or Fort Bend County, see IntegraFin’s IRS notice review service. You can also read the IRS’s complete notice search.
Common questions
Using the IRS notice finder
Where is the IRS notice number?
The IRS says the CP or LTR number is generally near the right corner of the letter. Look for a code such as CP504, CP2000, LT11, or Letter 12C; enter only that code here.
What if my IRS letter code is not in this finder?
Use the IRS notice-and-letter search linked above. This finder covers a reviewed set of common codes and will not guess at an unknown number. If a letter seems suspicious, verify it using IRS.gov or the IRS phone number you find independently.
Does a notice code tell me my response deadline?
No. Read the date and instructions on your actual notice. The tax year, case history, requested action, and any appeal rights can differ even when the code is the same.
Is IntegraFin part of the IRS?
No. IntegraFin is an independent tax and accounting firm. The finder summarizes public IRS pages and links to the official source for each result.