IRS Notices

IRS CP24 Notice: Estimated-Tax Discrepancy and Your Refund (2025)

By Angeline Balsitis, EA · Reviewed by Melissa Ly, Chief Tax Officer · Updated June 29, 2026 · Editorial Standards

Why you got a CP24 notice

A CP24 notice goes out when the IRS matches the estimated tax payments (the quarterly payments many self-employed people and retirees make) you reported on your return against the payments its own records show actually posted — and the two don't line up. With a CP24, the difference works in your favor: the IRS now shows you paid more than your return claimed, so you have an overpayment coming back. The IRS explains its version at Understanding your CP24 notice.

Common reasons the numbers don't match:

• An estimated payment was credited to the wrong tax year and then reapplied.
• You forgot to claim a payment you actually made.
• A withholding or credit amount was entered slightly off on the return.
• A prior-year overpayment was rolled forward differently than you expected.

The notice lists the tax year, what you reported, what the IRS recorded, and the new refund amount. It's the cousin of the CP23 notice, which is the same estimated-tax comparison — except the CP23 ends with a balance due instead of a refund.

Is a CP24 good news? Usually — but verify it first

A refund notice feels like a win, and most of the time it is. But the IRS adjusted your return without you in the room, so the single most important step is confirming its math matches yours. The adjustment is only correct if the payments the IRS credited are the payments you really made.

Take ten minutes to check before you spend the money:

• Log into your IRS online account and look at your payment history and account balance for that tax year. Compare it line by line with the CP24.
• Pull your records — canceled checks, bank statements, or electronic payment confirmations for each estimated payment.
• Watch for scams. A real CP24 arrives by postal mail, never by email or text, and the IRS never asks for gift cards or wire transfers. If you're unsure whether a letter is genuine, our guide on how to tell if an IRS letter is real walks through the tells.

When will your refund arrive — and what could delay it

If you agree with the CP24 and owe no other federal or state debts, the IRS generally issues the refund within about 4 to 6 weeks of the notice date. A few things can change that timeline:

1. You owe federal back taxes. The refund is applied to that balance first. You'd typically see a separate notice — often a CP49 showing the refund was applied to an older year.
2. You owe other government debts. Past-due child support, state taxes, or defaulted student loans can grab the refund through the Treasury Offset Program before it ever reaches you.
3. Your return is still under review. If another hold is on the account, the money waits until that clears.

You can track the payment on your IRS online account and through the Where's My Refund tool. If a refund you were promised never shows up, that almost always means an offset — not a mistake.

What to do if you disagree with the CP24

Sometimes the IRS's "correction" is itself wrong — it dropped a payment, double-counted one, or credited the wrong year. If the new refund is smaller than it should be, or the notice changed something you believe was right, you have 60 days from the notice date to push back.

Here's a worked example. Say you made four $2,000 estimated payments — $8,000 for the year — but one payment was posted to the prior year by mistake. The IRS only sees $6,000, so its CP24 refund is $2,000 short of what you're owed. With the canceled check and your account transcript showing the misapplied payment, the IRS can move it to the correct year and release the rest of your refund.

How to respond, step by step

1. Read the whole notice. Note the tax year, the "we changed" figures, and the new refund amount.
2. Verify the numbers against your IRS online account and your own payment records (see above).
3. If everything matches and you agree: do nothing. The refund comes automatically. File the notice with your tax papers.
4. If you disagree: call the number on the notice within 60 days with your proof in hand, or respond in writing and keep copies of everything you send.
5. If the refund never arrives: check for an offset before assuming an error — log into your account and review the rules on refunds being taken for back taxes.

CP24 questions, answered

This guide is general information, not tax or legal advice for your specific situation. Eligibility for IRS programs depends on individual facts and circumstances; no outcome is guaranteed.

Related guides: IRS CP25 Notice: Estimated-Tax Discrepancy and a $0 Balance, Explained · IRS CP2501 Notice: What It Means, Your Deadline, and How to Respond · IRS CP2566 Notice: What It Means, Your Deadline, and What to Do · IRS CP27 Notice: EITC With No Qualifying Child, Explained · IRS CP297 Notice: What It Means, Your Deadline, and What to Do