Requirements to Withhold Connecticut Income Tax: If you maintain an office or transact business in Connecticut and you are considered an employer for federal withholding purposes, you must withhold Connecticut income tax whether or not your payroll department is located in Connecticut. Special rules apply to payers of nonpayroll amounts and payers of compensation to professional athletes and entertainers.

Registering to Withhold Income Tax: If you are required to withhold Connecticut income tax, you must register for withholding tax with DRS.

• If your business has a valid Connecticut tax registration number from the Connecticut Department of Revenue Services, you may add withholding tax to the existing registration by logging into the Taxpayer Service Center (TSC-BUS) using your existing CT Tax Registration number and selecting "Register for Additional Tax Types" on the left toolbar.
• If your business does not have a Connecticut tax registration number from the Connecticut Department of Revenue Services, you must complete Form REG-1, Business Taxes Registration Application.

IMPORTANT: Employers are also required to register with the Connecticut Department of Labor for unemployment and workers compensation taxes. Please telephone that agency at 860-263-6000 or visit that the DOL website.