Must an organization obtain an employer identification number to apply for exemption? An organization may not file Form 1023 unless it already has an Employer Identification Number (EIN). An organization can obtain an EIN online, by fax, by mail, or over the phone (international applicants only). Interactive training Learn more about the benefits, limitations and expectations of tax-exempt organizations by attending 10 courses at the online Small to Mid-Size Tax Exempt Organization Workshop.