An employer identification number (EIN) is a nine-digit number assigned by the IRS. It's used to identify the tax accounts of employers and certain others who have no employees. The IRS uses the number to identify taxpayers who are required to file various business tax returns. EINs are used by employers, sole proprietors, corporations, partnerships, non-profit associations, trusts, estates of decedents, government agencies, certain individuals, and other business entities. If you already have an EIN and the organization or ownership of your business changes, you may need to apply for a new number. For more information, refer to Do You Need an EIN and Publication 1635, Understanding Your EINPDF. Daily Limitation of an EIN and Security Enhancement To ensure fair and equitable treatment for all taxpayers, the IRS issues only one EIN per responsible party per day. This limitation is applicable to all requests for EINs, whether online, by telephone, fax or mail. We apologize for any inconvenience this may cause. Only individuals with taxpayer identification numbers can apply for an EIN as the responsible party. Applying for an EIN If your principal place of business, office or agency, or legal residence (in the case of an individual) is located in the United States or U.S. Territories, you may apply for an EIN as follows: Online - The Internet is the preferred method to use when applying for an EIN. The online EIN application is available Monday to Friday, 7 a.m. to 10 p.m. Eastern Standard Time. Once the application is completed, the information is validated during the online session, and an EIN is issued immediately. Taxpayers who apply online can view, print, and save their EIN assignment notice at the end of the session. Authorized third party designees will receive the EIN; however, the EIN assignment notice will be mailed to the applicant. The online application isn't available for entities with foreign addresses or for applications in which the responsible party is an entity with an EIN obtained through the Internet. The principal officer, general partner, grantor, owner, trustor, etc. must have a valid taxpayer identification number (SSN, EIN, or ITIN) in order to use the online application. Search the term EIN on IRS.gov for more information. By Fax - You can fax the completed Form SS-4, Application for Employer Identification Number to the fax number listed in the Instructions for Form SS-4PDF or see "Where to File Your Taxes" (for Form SS-4). You can receive your EIN by fax generally within 4 business days. You can apply by fax 24 hours a day, 7 days a week. By Mail - You can mail the completed Form SS-4 to the IRS service center address listed in the Instructions for Form SS-4PDF or see "Where to File Your Taxes" (for Form SS-4). Ensure that the Form SS-4 contains all of the required information. Mail Form SS-4 at least 4 to 5 weeks before you need your EIN to file a return or make a deposit. You will receive your EIN in the mail in approximately 4 weeks. International EIN Applicants If you have no principal place of business, office or agency, or legal residence in the United States or U.S. Territories, you're considered an international applicant. You can only apply for an EIN as follows: By Telephone - If you're an international applicant, you may call 267-941-1099 (not a toll-free number), 6 a.m. to 11 p.m. Eastern time, Monday through Friday, to obtain an EIN. You must be authorized to receive the EIN and answer questions concerning the Form SS-4PDF. When applying by telephone, it's helpful to complete the Form SS-4 before contacting the IRS. An IRS representative will use the information from the Form SS-4 to establish your account and assign you an EIN. By Fax or Mail - You can apply by fax or mail as indicated above.