Start with the actual company
Write the name exactly as the provider gives it, along with the license number. Ask whether the name on the proposal and invoice will match. If a different company is being dispatched, obtain that company's identity before authorizing work. A license belonging to an unrelated business does not answer who is responsible for your project.
The Illinois Department of Public Health plumbing page links the official verification system. Use that current route rather than a screenshot supplied without context. Compare the name and record details carefully, and ask IDPH about an unclear or conflicting result.
Check other project requirements separately
A state record does not, by itself, settle every local contractor-registration, permit, insurance, or scope requirement. Ask the Gurnee Building Division what applies to your address and work. Request appropriate insurance information from the actual provider when evaluating the project.
Keep evidence with the proposal
Record the date you checked, the name and number reviewed, and any clarification received. Keep that with the written estimate. If the business changes during the project, repeat the identity check instead of assuming the original record covers the replacement company.
IDPH also discusses license-number requirements for plumbing advertising. This publisher is not a substitute for a contractor's own identification. If the recipient will not clearly identify the business or resolve a mismatch, do not treat the referral as an endorsement that removes the need to check.