Mail or Fax Form SS-4: If your principal business, office or agency, or legal residence in the case of an individual, is located in: Mail or Fax Form SS-4 to: One of the 50 states or the District of Columbia Internal Revenue Service Attn: EIN Operation Cincinnati, OH 45999 Fax: (855) 641-6935 If you have no legal residence, principal place of business, or principal office or agency in any state: Internal Revenue Service Attn: EIN International Operation Cincinnati, OH 45999 Fax: (855) 215-1627 (within the U.S.) Fax: (304) 707-9471 (outside the U.S.)