USTaxPenaltySaverCP23
MediumEstimated Tax Payments Changed - Balance Due
The IRS changed the estimated tax payments shown on your return to match its records, and you now owe a balance.
Last reviewed: November 10, 2026. Check irs.gov for changes.
Read the full guide to this noticeWhat This Notice Means
The IRS sends CP23 when the estimated tax payments on your return do not match the payments posted to your account. The most common cause is an incorrect entry on the estimated tax line of the return. Pay by the date on the notice if you agree; if you disagree, call the number on the notice by that date (irs.gov "Understanding your CP23 notice", updated 3 November 2026).
Why You May Have Received This
- 1Wrong amount entered on the estimated tax line of the return
- 2A payment that posted differently from what the return shows, for example to another tax year
Required Actions
Compare the payments on the notice with your bank records and your IRS online account
If you agree, pay by the date on the notice or set up a payment plan
If you disagree, call the number on the notice by the date shown, with proof of each payment
Your Options
Use these calculators to understand your situation and explore resolution options.
Free letter templates
If you want to ask the IRS to remove the penalty, start from a free template you can copy, edit and send.
Consequences If Ignored
- Interest and the failure-to-pay penalty keep growing
- Balance-due reminders follow (CP501, CP503, CP504)
Tips & Best Practices
- The IRS says interest cannot be reduced for reasonable cause or first-time relief
- A late-payment penalty usually applies; if the IRS fixes a misapplied payment, the penalty and interest adjust automatically
- Look for a payment the IRS posted to a different year before you pay
Related Resources
Legal References
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