Submitting this form only withholds Pennsylvania state income tax from your pay. Complete Form REV-419 so that your employer can withhold the correct.Pennsylvania personal income tax from your pay. What are Pennsylvania's employer withholding requirements? Complete Form W-4 so that your employer can withhold the correct federal income tax from your pay. Give Form W-4 to your employer. As a part-year resident, you are subject to PA tax on ALL income earned, received, or credited for that part of the year you were a PA resident. Purpose. Complete Form REV-419 so that your employer can withhold the correct Pennsylvania personal income tax from your pay. The most common Pennsylvania income tax form is the PA-40. If you must amend an Earnings Tax return, complete a new return with the updated amount.