CP268 tells you we made changes to your return because we believe there is a miscalculation on your return. If you do not complete and include Form 203 with your income tax return, your share of the overpayment may be applied to past due liabilities.You can get in-person help at your local IRS Taxpayer Assistance Center. Call for an appointment after you find a Taxpayer Assistance Center near you. Taxpayers can call (602) 255-3381, and, after making the language selection, select Option 2 for refund status. You get an overpayment credit when your tax payments exceed what you owe. You'll automatically receive a refund of the credit. Get your refund status. Locate the closest Taxpayer Assistance Center to you. Sign in or create an online account.