Part 1 – Complete this part to calculate your withholding allowances for New York State and Yonkers (line 1 of Form IT-2104). The questions on this web page are about the Treasury Offset Program, the program that withholds money to pay for a debt.Find tax withholding information for employees, employers and foreign persons. Instructs employers and federal agencies on how to process income withholding orders including examples of calculations. Employers generally must withhold federal income tax from employees' wages. To figure out how much tax to withhold, use the employee's Form W-4. If Withholding Tax Allowance was elected, you must file a RITA claim within 120 days of the following calendar year. You must give Form NJ-W4 to your employees to fill out and return to you. This form tells you how to withhold tax from your employee's pay. If you're an employer, you need to withhold Massachusetts income tax from your employees' wages.