Union fringes often consist of contributions to Vacation/Holiday, Health & Welfare, Pension, Training, and sometimes Travel & Subsistence, Savings, or Fund Administration. Depending upon the Union that you are dealing with, some of the fringe benefits could be subject to payroll taxes, while others are not. Most of the time fringes are calculated and paid based on the number of hours the employee works on the jobsite, occasionally, however, they are a based on a percentage of gross pay.