What is the CP 45 notice?
The IRS sends this notice to inform you that they made one or more changes to your return that resulted in a reduced refund. Since you requested that part or all of the overpayment be applied to the following year's estimated tax, they are sending the notice to let you know that they couldn't apply as much as you requested.
What do I have to do?
If you agree with the changes, adjust your tax return and estimated payment records to show the changed amount of overpayment applied to next year's tax return. If you don't agree with the changes, write or call them at the address or phone number listed on the notice.
You can also check your
IRS Online Account for recent changes.