Today is the end of the third quarter of 2022; the fourth quarter begins tomorrow, and some federal tax-related changes start then. The federal government’s fiscal year starts October 1, so some rules change. For example, new GSA per diem rates for business travel in the government’s 2023 FY that can be used to substantiate cost begin tomorrow. The IRS interest rates for overpayments and underpayments for Q4 2022 are higher. #IdeaoftheDay