Employees who have questions about their paychecks, need a replacement W-2 or have related concerns can call ADP Resource's toll-free Employee Service Center hotline. ADP Resource employee service representatives are available Monday through Friday, 8 am to 10 pm, Eastern Time. In most cases, they are able to provide immediate answers and assistance. If not, they either get back to the employee within a short time with a resolution or refer the employee to the appropriate resource.