CP268 tells you we made changes to your return because we believe there is a miscalculation on your return. Locate the closest Taxpayer Assistance Center to you.Use Form 843 to claim a refund or request an abatement of certain taxes, interest, penalties, fees, and additions to tax. (561) 616-2002 ; Appointment Phone (M-F 7 am-7pm). To request a tax refund, file an Application for Refund - Sales and Use Tax (Form DR-26S) or Application for Refund - All Other Taxes (Form DR-26). IRS uses CP268 to notify you that the IRS made changes to your original return due to an error. The change(s) resulted in an overpayment credit. You get an overpayment credit when your tax payments exceed what you owe. You'll automatically receive a refund of the credit. Some of the most common IRS tax notices received are: CP10: If this notice is received, then the IRS has adjusted an item in your current year's tax return.