CP10: We Changed Your Return and It Affected Your Estimated Tax for Next Year

Why you might get this

• You made one or more errors on your tax return that the IRS corrected.
• You asked to apply part of your refund toward next year's estimated tax (money you prepay toward taxes you expect to owe).
• The correction changed the amount the IRS was able to apply to next year.

The deadline

If you disagree with the changes, you need to contact the IRS by the date printed on your notice. Reaching out by that date protects your formal right to have the change reversed and your right to appeal to the U.S. Tax Court. If you contact the IRS after that date, they may still look at your information and could still reverse the change if they agree with you — but you may lose those formal rights.

This notice doesn't carry a fixed response deadline, but it still deserves attention — see what to do below.

What to do

1. Read your notice carefully and find the section that explains what was changed on your return.
2. If you agree, you don't need to respond. Just fix your own copy of the return for your records — don't mail it back.
3. If a refund is due, watch for it to arrive in the coming weeks, as long as you don't owe other taxes or debts.
4. If you disagree, call the number on your notice by the date shown. The phone is usually the fastest way to sort out return errors.
5. If the IRS asks for a missing or corrected form, you can fax it while on the call.
6. Consider adjusting your estimated tax payments with Form 1040-ES if the change affects your plan for next year.
7. If you need to make another correction yourself, file Form 1040-X (Amended U.S. Individual Income Tax Return).

What happens if you ignore it

If you don't contact the IRS by the date on your notice, you lose the formal right to have the change reversed and the right to appeal the decision to the U.S. Tax Court. If the IRS reduced your refund and doesn't get information supporting your original return, it may send your case to audit.

If your case moves to an audit, the audit staff should contact you within about six weeks to explain the process and your rights. You can authorize someone to represent you, and you may qualify for free help from the Taxpayer Advocate Service or a Low Income Taxpayer Clinic.

What a CP10 Notice Means

A CP10 notice tells you the IRS found and corrected one or more mistakes on your tax return. This correction changed the amount you asked to apply toward next year's estimated tax — the money you prepay toward taxes you expect to owe.

Start by reading the notice closely. Look for the section that explains exactly what changed and how it affected the amount carried over to next year.

If you agree with the change, you don't have to do anything. Just update your personal copy of the return for your records — don't mail it back. If a refund is coming, it usually arrives within a few weeks, as long as you don't owe other taxes or debts.

If you disagree, call the phone number on your notice by the date printed there. Contacting the IRS on time protects your right to have the change reversed and your right to appeal to the U.S. Tax Court. The phone is often the quickest way to fix return errors, and you can fax any documents the IRS needs while you're on the call.

Solace can keep an eye on your IRS account and flag changes for you, so nothing catches you off guard.