Professional Employment Documents Everything you need to work with Career Concepts Staffing Services: Form W-4 Click here to download Form W-4, Employee’s Withholding Allowance Certificate. Form I-9 Click here to download the form I-9, Employment Eligibility Verification. Plan 1 – Change Form (English) Click here to download the form regarding your health insurance designations. Plan 1 – Formulario De Cambios (Español) Haga clic aquí descargar el de considerar a sus designaciones de seguros de salud. Change of Address Form Click here to change your address with Career Concepts Staffing Services. Paychecks by Mail Form Click here to download the form to specify your paycheck preferences.