This EIN confirmation letter is called CP 575, and the IRS only mails the letter to the mailing address listed on line 4 of the SS-4 application. The only two ways to get an EIN Verification Letter (147C) is to call the IRS at 1-800-829-4933, or to mail the IRS a written request.However, you will need Adobe Reader installed if you would like to receive a confirmation letter online. CP-575 is a notice from the IRS informing the taxpayer that they have been successfully approved for a unique employer identification number (EIN). This confirmation letter is known as Form CP 575 and is mailed to the address mentioned in your Form SS-4 application. Find out what you need to do if you have lost or misplaced your Employer Identification Number (EIN). You'll need a Tax Department Business Online Services account to file your sales tax returns online. Custom Computer Programming Services. Part I. Taxpayer Identification Number (TIN). Give Form to the requester.