Payroll expense is the amount of salaries and wages paid to employees in exchange for services rendered by them to a business. The term may also be assumed to include the cost of all related payroll taxes, such as the employer's matching payments for Medicare and social security.
In a cash basis company, payroll expense is the cash paid during an accounting period for salaries and wages. In an accrual basis company, payroll expense is the amount of salaries and wages earned by employees during the period, whether or not these amounts were paid during that period.
Payroll expense may be the largest expense that a company incurs, especially when it is in a services industry where revenues are directly related to staff hours worked. Conversely, payroll expense may be a much less substantial proportion of total expenses in a business that is fixed-asset intensive, such as an oil refinery.