However, you will need Adobe Reader installed if you would like to receive a confirmation letter online. 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. The hours of operation are 7 a.m. This confirmation letter is known as Form CP 575 and is mailed to the address mentioned in your Form SS-4 application. Complete all information on this form, sign, date, and submit the form. Enter first name, last name, email, and mobile number of the primary contact in the relevant fields. Click Here to conduct a Clerk Records Search (Fictitious Business Names, Environmental Filings, Notaries, and Registrations). The following links will help ensure businesses are properly licensed, and, if needed, registered with the state. Starting a business involves planning, making key financial decisions and completing a series of legal activities.