How to Hire a Licensed Plumber in Illinois: A 2026 Checklist

Illinois is one of the stricter states for plumber licensing. Plumbers are licensed at the state level through the Illinois Department of Public Health (IDPH), and they must follow the Illinois Plumbing Code. The City of Chicago runs its own separate licensing and inspection program inside city limits.

A licensed plumber has met training and exam requirements and carries accountability if something goes wrong. An unlicensed handyman may be cheaper today and far more expensive after a failed repair floods a finished basement.

Run through these seven items for every plumber you are considering.

1. 1License. Ask for the IDPH plumber or plumbing-contractor license number, plus the Chicago license if the job is in the city.
2. 2Insurance and bond. Confirm general liability insurance and bonding, and ask for a certificate if the job is large.
3. 3Written estimate. Require an itemized, written estimate before work begins. See typical numbers in our drain cleaning cost guide.
4. 4Reputation. Read recent reviews and ask for references on bigger jobs.
5. 5Permits. For water heaters, repipes, sewer work, and gas lines, a permit and inspection are often required. A pro who skips permits is a warning sign.
6. 6Warranty. Ask what is warrantied, for how long, and whether it covers both parts and labor.
7. 7Payment terms. Reasonable deposits are normal on large jobs. Full payment in cash before any work is not.

You do not have to take a plumber's word for it. Both the state and the city publish public lookups.

State (IDPH) license

Search the IDPH Plumbing Program for the license number the plumber gives you, and confirm the name matches the business.

Chicago license

For work inside Chicago, check the City of Chicago Department of Buildings contractor and permit lookups. Every business in our directory shows the public registry data we matched it to, and you can read how we do that on our verification page.

• Refuses to provide a license number or proof of insurance
• Will only give a price in person and pressures you to decide on the spot
• Demands full payment in cash before starting
• Has no written estimate or contract
• Wants to skip permits on work that legally needs them
• Quotes a price far below every other bid, which often means an unlicensed crew

If you are dealing with a true emergency such as a burst pipe, the pressure is real, but the fundamentals still apply. Our plumbing emergency guide explains how to act fast without getting taken advantage of.

A short conversation prevents most disputes.

• Is this price flat-rate or hourly, and what could change it?
• Who pulls the permit, and is the inspection included?
• What warranty comes with the parts and the labor?
• Will you haul away the old water heater, fixture, or debris?
• Who is the actual licensed person on site, not just the company name?

Keep the signed estimate, the permit, and the final invoice together. If a repair fails inside the warranty window, those documents are your leverage.

When you are ready, you can browse licensed Illinois plumbers by city, or learn the early signs you need a plumber so you call before a small issue becomes an emergency.