Oklahoma Form U-5 is an official document issued by the Oklahoma Tax Commission. It is a multi-purpose form used for filing taxes, registering a business, and requesting information from the Oklahoma Tax Commission. There are three types of Oklahoma Form U-5: the General Form U-5, the Unified Business Tax Form U-5, and the Withholding Tax Form U-5. The General Form U-5 is used to register a business, report changes in ownership or dissolution, and report personal property taxes. The Unified Business Tax Form U-5 is used to register a business for the Unified Business Tax and report the annual gross proceeds/receipts of the business. The Withholding Tax Form U-5 is used to register for withholding taxes and to report the amount of tax withheld from employees' wages.