How do i get a wholesale license in illinois? How to Get a Wholesale License in Illinois. Fill out the Illinois Business Registration application. You can do this online at the Illinois Department of Revenue website (see Resources), or you can print out a copy of the REG-1 form (see Resources) and mail it to the address at the bottom of the form.How do i contact the illinois tax office for assistance? To receive assistance by phone, please call 800 732-8866 or 217 782-3336. Representatives are available Monday through Friday, 8 am - 5 pm. Our TDD (telecommunication device for the deaf) number is 800 544-5304. To receive assistance by email, use the information below. Inpidual Income Tax [email protected] Local Tax Allocation DivisionHow do i contact the illinois comptroller of illinois? Office of the Comptroller - Springfield. 325 West Adams. Springfield, Illinois 62704. (217) 782-6000. Records Center: (800) 877 8078. Office of the Comptroller - Chicago.What is this directory of illinois products for? This directory of Illinois products is provided for the assistance of designers and contractors doing business with CDB. The products listed are manufactured, fabricated or assembled in Illinois. The companies may not be headquartered in Illinois but manufacture some products in Illinois.