Thanks for your question.
The CP575 is the notice the IRS issues when you are assigned an EIN. The IRS is unable to reissue or provide a copy of the CP575 notice. If you lost your original notice and need confirmation of your EIN, call the IRS business help line at 1-800-829-4933 and tell them you cannot find your CP575 and would like a confirmation letter of your EIN.
The IRS will then send you a 147C letter that may be used instead of the CP575 notice. You may send a written request for the letter 147C but it would be faster to call and request on the phone.
Hope this helps,