Form SS-4 is one page with eighteen numbered lines, and most are straightforward. For a company whose owner has no Social Security Number a few aren't, and getting one of those wrong can mean a rejected application or an EIN for the wrong kind of entity. Here's the form line by line, with the answers for a foreign-owned single-member LLC and the differences for a partnership or a corporation.
Lines 1 to 7: who the company is
Lines 8 and 9: what kind of entity
Line 9a sets what the IRS expects from the company every spring. A single-member LLC that ticks Corporation has told the IRS to expect a corporate tax return. It can be corrected, but that takes a letter and several weeks, so check the box before you send the form.
Lines 10 to 18: why, when and what
Third-party designee and signature
The designee section names someone the IRS can talk to about the application, which is how a filing agent follows it up. That authority only counts if the form is signed, and it ends once the EIN is assigned. The responsible party signs, with their title, such as Member, Managing Member or an officer's title.
Where to send it
The IRS lists separate fax numbers and a postal address for applicants with no legal residence, principal place of business or principal office in the US, along with a phone line on which those applicants can get the number during the call. The numbers change now and then, so use the ones in the current SS-4 instructions rather than a number from a forum post. A company with a principal office in the US uses the domestic fax number instead.
After you send it
The IRS assigns the number and, if you gave a return fax number, faxes it back. The CP 575 confirmation is posted to the mailing address. For a foreign-owned company, twenty to thirty business days is normal by fax, while the phone route gives you the number the same day, if you can get through. The EIN guide covers the routes and timing.