What You Should Know about Hiring a Contractor in Illinois In Illinois, the licensing process for contractors varies by locality. Individuals or entities engaged in construction or plumbing work should verify the licensing status of any contractors with the relevant city or county authorities, or the Illinois Department of Public Health (IDPH) and the Illinois Department of Financial and Professional Regulation (IDFPR), particularly for plumbing and roofing contractors. When engaging contractors, it is essential to thoroughly review insurance and bonding requirements, and obtain multiple quotes. It is imperative to insist on written contracts and exercise caution against scams, especially those involving high-pressure tactics.