A2ABefore answering directly, I will make the following point in response to the prior answers: One faxes Form SS-4 (Application for EIN) to the IRS if the applicantu2019s responsible party lacks a U.S. social security number, thus obtaining an EIN online is impossible. (Faxing is faster and more reliable that hard-copy submission via the Postal Service.)The IRSu2019s target date to fax back an EIN is four business days.I allow one week, plus an extra day if there is an intervening holiday.In my experience, the IRS achieves this turnaround ~80u201390% of the time. On rare occasion, I have received an EIN in two or three business days.If I do not receive an EIN within one week, I call the next day: Sometimes the EIN has been assigned but not yet faxed, so I am told it over the phone, sometimes it is not yet assigned, so I have to wait, sometimes the IRS has no record of the application, so I have to start all over again.