STATE LICENSE
ConditionalOhio Construction Industry Licensing Boar…
Plumbing follows the OCILB split: the state plumbing contractor license is required on commercial 'construction projects' but not on one-, two- and three-family dwellings (R.C. 4740.01(F)). Hydronics (steam and hot water) is a separate OCILB license. Cities decide the residential side — Columbus, Cincinnati, Toledo and Dayton require the state license to register a plumbing contractor, Cleveland requires it for new and commercial registrations, and Columbus also licenses individual journeyperson plumbers.
One statewide rule cuts across the split: under R.C. 3703.21, no individual may install, test or repair an isolation backflow prevention device without a backflow technician certificate from the Division of Industrial Compliance. Class A covers any device and requires five years with a licensed plumbing or hydronics contractor (or a plumbing inspector certification).
The state sets the license floor; the county or city permit office controls filing, inspections, and local rules wherever the job site sits.
Because R.C. 4740.01(F) carves one-, two- and three-family dwellings out of 'construction project', the state license is legally commercial-only — but OCILB itself warns that local building departments may require it for residential work, and Ohio's big cities do. R.C. 4740.12(A) shapes how: no political subdivision may charge a contractor registration or license fee for these trades unless its ordinance also requires the registrant to hold the state license, while 4740.12(B) leaves cities free to regulate the installation work itself and to register tradespersons. In practice: Columbus will not register an electrical, HVAC, refrigeration, hydronics or plumbing contractor who is not state-licensed, charges a $350 annual registration fee, and separately licenses journeyperson plumbers. Cleveland requires every new or commercial trade registration to attach the state license ($150 new, $120 renewal, $25,000 bond, $200,000 insurance, expiring December 31); its form offers a '1, 2, 3 Family Only' scope alongside 'All Work', and older registrants renewing without a state license are held to residential-only work. Cincinnati registers OCILB contractors in their own class under Municipal Code Chapter 1106 ($131.25 a year, up to three years, expiring on the state license date). Toledo's trade registration ($200 application) requires a copy of the current state license, including for its separate 'Electrical Contractor Residential' class. Dayton's 2026 trade registrations require the state license, a $10,000 bond expiring December 31, and $100,000/$300,000 liability insurance. Akron requires every contractor whose work needs a permit to register, attach any state license the trade requires, and carry $3 million in liability coverage. Outside these cities, whether a residential trade contractor needs any credential depends entirely on the local building department.
The local offices section below names the exact permit desk for every Ohio county on file.
Each row names the issuing authority, cost, timeline, citation, and status behind the requirement — verified against the official source.
Published fees from the issuing authorities, as of October 2026. Local permit fees vary by project and jurisdiction — the basis is stated where a flat number does not exist.
OCILB's experience proof accepts one permit per year for five years from your employer — but sewer service, water service, gas service and drain cleaning permits do not count.
Even an OCILB plumbing licensee needs a separate backflow technician certificate to install, test or repair isolation backflow preventers; renewal is every three years with an 8-hour course.
Dayton plumbing registration requires a $10,000 bond running January 1 to December 31 and $100,000/$300,000 liability with completed operations.
A practical sequence for a new plumbing contractor in Ohio. Actual agency processing times are noted in the ledger above.
Each item names the issuing authority, cycle, and citation.
Statutory consequences with their citations — not estimates, not “commonly cited” guesses.
Acting as or claiming to be a plumbing contractor without the OCILB license.
No individual may install, test or repair an isolation backflow prevention device without certification.
Suspension, revocation or refusal of the license, added CE, or a fine.
Inside city limits, the city office listed here issues the permit; the county office serves unincorporated areas. Every office links to its official page.
Every fact in this file was checked against these official sources on October 2026.
Pending verification: PSI exam vendor fee (not published on com.ohio.gov) · Dayton's journeyman plumber registration fee and requirements (form listed but not retrieved) · Which agency inspects residential plumbing in jurisdictions without a city plumbing program (varies by county)
General information, not legal advice. Always confirm requirements, deadlines, and forms with the issuing authority before filing or contracting.
Store licenses, permits, policies, and renewal dates in one place.