# Commercial Plumbing Permits in St. Louis > How commercial plumbing permits and inspections work in St. Louis City, St. Louis County and St. Charles County — who issues them and who can pull them. Canonical: https://legacyplumbingmo.com/resources/commercial-plumbing-permits-st-louis-st-charles Last updated: 2026-10-27 [Resources](https://legacyplumbingmo.com/resources) Compliance How commercial plumbing permits and inspections work in St. Louis City, St. Louis County and St. Charles County — who issues them and who can pull them. October 27, 2026 4 min read Written and reviewed by the Legacy Plumbing field & estimating team Last reviewed: October 2026 · Legacy Plumbing is a union commercial plumbing contractor serving St. Louis since 1996. In the St. Louis metro, commercial plumbing permits are issued by the local jurisdiction where the building sits — the City of St. Louis, St. Louis County or the municipality, [St. Charles County](https://legacyplumbingmo.com/locations/st-charles-county) , or a city inside St. Charles County — and in most cases the permit must be pulled by a plumbing contractor licensed by that jurisdiction. There is no single metro-wide permit, so the first step on any commercial job is to confirm who has authority over the address. This post explains how the process works in each area based on what the jurisdictions publish. Rules, portals and requirements change, so confirm current requirements with the jurisdiction before you schedule work. We have left out fees and review times on purpose; get those directly from the permitting office. ## Who issues plumbing permits in the City of St. Louis? The City of St. Louis Building Division handles plumbing permits. According to the city, plumbing permits are issued to licensed plumbing contractors who are certified by the City of St. Louis. To pull one, a contractor needs a plumbing contractor's license issued by the city's Building Division and a registered trades contractor account on the STL City Permits website. - Apply online through the contractor's STL City Permits account, or in person at the Building Division's Plumbing Section in City Hall - Work the city lists as requiring permits and inspections includes new plumbing fixtures, soil pipe connections, and replacement of sewer laterals, soil stacks, vent pipes and water supply lines - Once a permit is approved, the contractor prints it and schedules inspections through the online dashboard For a commercial project, building plan review is a separate process. Ask the Building Division what plumbing drawings it needs with the building permit submittal. ## How does plumbing permitting work in St. Louis County? St. Louis County is more complicated because it includes unincorporated areas and dozens of municipalities. Many municipalities adopt the County's plumbing code and rely on the County for plumbing enforcement. A 2021 review by St. Louis REALTORS found that municipalities often adopt the County's codebook for electrical, mechanical and plumbing work, and that developers may need permits from both a city and St. Louis County for plumbing. Some municipalities take plumbing permit applications themselves while still relying on County licensing. [University City](https://legacyplumbingmo.com/service-area/university-city-mo) , for example, states that plumbing permits are issued to master plumbers or drainlayers licensed by St. Louis County, and that applications are submitted to the city's Community Development Department. - Confirm whether the address is unincorporated or inside a municipality - Ask the municipality whether it issues plumbing permits or sends you to St. Louis County - Confirm the contractor holds the St. Louis County license the permit requires - Ask which plumbing code edition applies and whether there are local amendments ## How does plumbing permitting work in St. Charles County? [St. Charles](https://legacyplumbingmo.com/locations/st-charles) County's Building and Code Enforcement Division states that plumbers are required to have a license through the division before doing any work in the county that requires a permit. The county's mechanical, electrical and plumbing permit is applied for through its online Citizenserve portal and asks for the names of the contractors doing the work and the estimated cost of construction. Related service: [Commercial New Construction Plumbing](https://legacyplumbingmo.com/services/new-construction) The county says at least one inspection is required, and inspections must be requested through the Community Development office by 5 p.m. the business day before the desired date. The permit must be posted where it is visible from the street. ### Cities inside St. Charles County Cities such as [O'Fallon](https://legacyplumbingmo.com/locations/ofallon) , St. Charles, [St. Peters](https://legacyplumbingmo.com/locations/st-peters) and [Wentzville](https://legacyplumbingmo.com/locations/wentzville) run their own building departments. O'Fallon, for example, states that commercial permits are required for any new commercial project, including alterations and additions, and that its Building Division performs plan review and inspections on new commercial properties. O'Fallon takes submittals and inspection requests through its CitizenServe portal and says inspections scheduled through the portal are typically completed the next day. Check licensing and registration requirements with each city as well as the county. ## What inspections should you plan for on a commercial job? The exact list depends on the jurisdiction and the scope, but commercial plumbing typically moves through these stages: - Underground — drain, waste and vent and water piping below the slab, tested and inspected before backfill - Rough-in — above-ground piping tested and inspected before walls and ceilings are closed - Gas piping — tested and inspected where gas is in the plumbing scope - Backflow — assemblies installed and tested, with reports filed as the water supplier requires - Final — fixtures set, systems working, and the permit closed out before occupancy ## How do you keep permits from holding up the schedule? - Confirm the permitting authority for the exact address before bidding - Make sure your plumbing contractor is licensed in that jurisdiction and pulls the permit directly - Ask the jurisdiction about current plan review requirements and timing instead of assuming - Request inspections on the jurisdiction's lead time, and leave room for a re-inspection - Keep the approved drawings and the permit on site for every inspection Legacy Plumbing works across St. Louis City, St. Louis County and St. Charles County and handles permitting and inspection coordination for the plumbing scope. Send your drawings and project address for a bid — commercial bids are returned within one business day — or call (636) 978-0120. ## Related services & projects - [Service areas](https://legacyplumbingmo.com/service-areas) - [Plumbing for general contractors](https://legacyplumbingmo.com/general-contractors) - [Backflow prevention & testing](https://legacyplumbingmo.com/commercial/backflow-prevention) - [Middle School Renovation in St. Charles (St. Charles, MO)](https://legacyplumbingmo.com/projects/middle-school-renovation-st-charles-mo) - [Retail Plumbing in South St. Louis County (St. Louis, South St. Louis County)](https://legacyplumbingmo.com/projects/retail-building-plumbing-south-st-louis-county) - [Facility Water Heater & Backflow Program (Regional Portfolio)](https://legacyplumbingmo.com/projects/facility-water-heater-backflow-program) Service Area Commercial Plumbing in St. Louis, MO See local coverage ## Talk to a St. Louis commercial plumber Send drawings or a scope and we'll return a written bid within one business day. [636-978-0120](tel:+16369780120) [Contact Us](https://legacyplumbingmo.com/contact-us) ## More Resources - [How to Choose a Commercial Plumbing Company in St. Louis](https://legacyplumbingmo.com/resources/how-to-choose-a-commercial-plumbing-company-st-louis) What facility managers, GCs and owners should check before hiring a commercial plumber in St. Louis — licensing, union labor, service capacity, safety and pricing. - [Commercial Hydro Jetting vs. Drain Snaking: Which Does Your Building Need?](https://legacyplumbingmo.com/resources/commercial-hydro-jetting-vs-snaking-st-louis) When to hydro jet commercial drain lines in St. Louis instead of snaking them — grease, scale and roots, how often to jet, and what a camera inspection adds. - [Commercial Water Heater Replacement in St. Charles County: A Planning Guide](https://legacyplumbingmo.com/resources/commercial-water-heater-replacement-st-charles-county) Planning a commercial water heater replacement in St. Charles or St. Louis? Signs it's time, tank vs. tankless, sizing, permits, and how to avoid downtime. ## Need a Plumber in St. Louis or the Surrounding Area? Written bids within one business day, scheduled service Monday–Friday 7am–4pm, and union-trained crews since 1996 across the St. Louis metro and a 2-hour radius. [Get Free Estimate](https://legacyplumbingmo.com/contact-us) [636-978-0120](tel:+16369780120) ## Related - [Contact Legacy Plumbing](https://legacyplumbingmo.com/contact-us) - [Company facts](https://legacyplumbingmo.com/company-facts) - [All pages (llms.txt)](https://legacyplumbingmo.com/llms.txt)