Make sure that when entering your federal tax refund information on the IRS website you use the Social Security number, the Filing Status and the amount of the federal tax refund as shown on the Form 1040 Line 35a - https://www.irs.gov/refunds
The mailing address for the federal tax return is based on your state and whether or not you will be including a tax payment. Go to this IRS website for the mailing addresses, by state. with and without a tax payment - https://www.irs.gov/filing/where-to-file-paper-tax-returns-with-or-without-a-payment
