Find the likely permit authority for any Illinois address
Enter a complete street address to see which county or municipal government is the likely starting point for a building or zoning permit — plus official contact information, sources, and what to confirm before you apply.
Address lookup
Confirm locally before you build
- A postal city or ZIP code does not establish legal jurisdiction — municipal and county boundaries can differ from mailing addresses.
- Intergovernmental agreements, delegated county permitting, or township building authority can change which office actually issues the permit.
- Separate permits may still be required for fire protection, septic/well or other health-department review, and driveway or road/right-of-way work.
This directory is informational and jurisdiction-reported. It is not legal advice and not a permit determination — verify current requirements with the listed authority before applying for or beginning work.
Permit process guide
Illinois building permit data
Municipality or county — it depends on the address
Depending on where a property actually sits, the permitting process may begin at a municipal building like a city or village hall, or at a county office such as a courthouse. Neither of the offices pictured below handles every permit in Illinois, and a courthouse is not necessarily where permits are issued — use the lookup above or the directory to confirm the correct office for a specific address.
Or browse the full directory
Why a ZIP code or mailing city isn't enough
ZIP codes are a postal delivery tool created by the U.S. Postal Service — they were never drawn to match municipal or county boundaries. Many Illinois ZIP codes and mailing-address "cities" cross into unincorporated county land, into a neighboring municipality, or span more than one taxing and permitting jurisdiction entirely.
The same is true of a postal city name: a property with a "Chicago, IL" or "Naperville, IL" mailing address may actually sit in unincorporated county territory, or inside a smaller neighboring village, because the post office assigns the nearest city name for mail routing rather than for legal jurisdiction.
This tool uses parcel-boundary geocoding from the U.S. Census Bureau to estimate the actual municipal or county boundary an address falls within. It is a helpful starting point, not a legal determination — always confirm with the local jurisdiction before applying for a permit.