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IRS CP23: Estimated Payment Discrepancy — Balance Due
Straight answer: A CP23 means the estimated tax payments you claimed on your return don't match what the IRS shows it received, and the difference plus any penalties makes a balance due.
How many days do I have to respond to a CP23?
21 days from the date printed on the notice (not the day you opened it). Pay or dispute by the notice due date, typically within 21 days, to limit interest.
Your response deadline is approximately — days from today.
What should I do right now?
- Pull your payment records (bank statements, EFTPS/IRS online account history) and compare to the notice.
- If a payment is missing from the IRS's list, respond with proof — misapplied payments (wrong year, wrong SSN, spouse's account) are common.
- If the IRS is right, pay or set up an installment agreement.
The costly mistake people make with a CP23
Paying the balance without checking — misapplied estimated payments are one of the most common IRS accounting errors, especially after divorce or an SSN/name change.
Do I need professional help with a CP23?
Usually self-serviceable with bank records. Get help if payments span multiple years or a business entity.
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