Licensing is essential for working legally on construction projects across Illinois, with most contractor licenses issued at the city or county level. Roofing contractors must be licensed by the Illinois Department of Financial and Professional Regulation (IDFPR), while plumbers are licensed through the Illinois Department of Public Health (IDPH). Electricians and general contractors are typically licensed locally, such as through the City of Chicago or other municipal departments. Proper licensing ensures compliance, builds trust, and opens the door to larger, higher-paying projects.