How do i have my refund directly deposited into my bank if I filed by mail?

If you already filed your tax return it is too late to change the way you receive your refund.   So if you chose direct deposit and entered banking information on your Form 1040, you will get a direct deposit.  Otherwise, the IRS will mail a check to the address on your tax return.

Bank information for direct deposit is on Form 1040 lines 35b, 35c, and 35d. If you entered the information in TurboTax before you printed or filed your tax return it will be there, whether you e-file or file by mail, and you will get your refund by direct deposit. Before you printed or filed your tax return, TurboTax asked you how you want to receive your refund. If you selected direct deposit, it prompted you to enter the bank information. If you did not select direct deposit, and you have already mailed your tax return, it's too late to select it now.