Reimbursement in payroll and expense claims is the repayment of funds to an employee for legitimate, work-related expenses they paid for out-of-pocket. It acts as a refund for company expenses—such as travel, meals, or supplies—and is typically not considered taxable income, distinguishing it from regular salary payments. Reimbursement in payroll and expense claims is the repayment of funds to an employee for legitimate, work-related expenses they paid for out-of-pocket. It acts as a refund for company expenses—such as travel, meals, or supplies—and is typically not considered taxable income, distinguishing it from regular salary payments.