Management Instruction FM-640-2023-1 - Postal Bulletin 22670 - Contents Finance Federal Taxation Percentage Rate for Supplemental Wages Postal Service™ employees are reminded that the percentages used to ta..." /> Management Instruction FM-640-2023-1 - Postal Bulletin 22670 - Contents Finance Federal Taxation Percentage Rate for Supplemental Wages Postal Service™ employees are reminded that the percentages used to ta..." />