Use this form to apply for excise tax registration for activities under sections 4101, 4222, 4662, and 4682. Current Revision Form 637 PDF Recent Developments Excise Taxes Imposed on Certain Chemical Substances by Sections 4661 and 4671 -- 26-JAN-2022 Safe harbors for sustainable aviation fuel credit -- 05-FEB-2024 Other Items You May Find Useful All Revisions for Form 637 About Form SS-4, Application for Employer Identification Number (EIN) Other Current Product
