IRS Notice CP 45 - Unable to Apply Refund/Overpayment Toward Payment of Your Estimated Tax
The IRS was unable to apply the taxpayer's overpayment to the following year's taxes as requested on the return. This could be caused by an adjustment to the filed return or the IRS record of payments made did not match the payments claimed on the return. The notice could also be generated if the IRS offset the refund against other taxes owed or other debts outstanding which are legally collectible through the IRS offset program.
Sections of the Notice:
This area contains the Notice Number, the applicable tax year, the notice date, your Social Security Number, and the IRS contact number.
This section explains the reasons for the changes to your Form 1040 or the payments credited to your account. You should adjust your records to reflect the adjustment and you may need to adjust your estimated tax payments to avoid any possible underpayment.
If you have questions or do not agree with the adjustment the notice directs you to contact the IRS at the number listed in the header section. The notice may also include a voucher to send along with the payment, if applicable.