The CP11 means the IRS made changes to your return during processing and the result is a balance due. Unlike the CP14 (which reflects the balance you already knew about from your return), the CP11 means the IRS changed something that created a new or larger balance.
What Changed
Common processing changes include math corrections, disallowed deductions or credits, adjusted income based on information the IRS received, recalculated filing status, and corrections to estimated tax or withholding credits. The notice shows each change the IRS made and the resulting impact on your tax.
The CP11A variant includes penalty assessments along with the processing changes. If you see a CP11A, the IRS both changed your return and assessed penalties.
Your 60-Day Rights
Changes made under the IRS's math error authority give you 60 days to request abatement. If you dispute the changes within 60 days, the IRS must reverse them and follow the normal deficiency procedures, which give you more rights including access to Tax Court. After 60 days, the changes become final.
What to Do
Compare every change to your original return. The IRS shows what they changed and why. If the changes are correct, pay the balance or set up a payment plan. If the changes are wrong, respond within 60 days requesting abatement and include documentation supporting your original entries.
Don't automatically pay without reviewing. The IRS's processing system makes mistakes. Withholding credits get lost. Estimated payments get misapplied. Schedule C income gets double-counted. Verify the math before you send money.
If you've received a CP11 and the changes don't look right, call us at (813) 229-7100.