SIC code for plumbing: 1711, and the NAICS code 238220

This page is for plumbing contractors who need a code for an insurance or bank application, a license or vendor form, SAM.gov or a tax return, and for sellers building a list of plumbers. It covers the SIC and NAICS codes, the plumbing-adjacent work that's coded elsewhere, Census counts and the federal size standard.

The plumbing codes in both systems

The NAICS index for 238220 lists plumbers, plumbing contractors, pipe fitting and steam fitting contractors, gas fitting contractors, fire and lawn sprinkler system installation, water heater installation, water softener installation, sump pumps, bathroom fixture installation, and building sewer hookups. If you do any of that as your main work, 238220 is your code, whether the job is a new building or a repair call.

Plumbing-adjacent work with other codes

The septic, well, electrical-controls and repair-only rows come from the Census cross-references for 238220, and drain cleaning is listed in the index for 561790. On the SIC side, drain, sewer and septic cleaning were all repair services (7699), not plumbing.

How SIC 1711 maps to NAICS

SIC 1711 isn't a one-to-one match. The Census concordance splits it three ways:

Going the other way, 238220 draws on four SIC codes: 1711, 1791 (Structural Steel Erection), 1796 (Installation or Erection of Building Equipment, NEC) and 7699 (Repair Shops, NEC). Some data vendors also publish extended codes such as six- or eight-digit "1711" subdivisions for sewer cleaning; those are their own, not part of the 1987 SIC manual. If a UK Companies House form asks for a SIC code, it means the UK SIC 2007 list, where plumbing is 43220, Plumbing, heat and air-conditioning installation.

The SEC's SIC list has no 1711 at all. Public plumbing and mechanical contractors file under 1700, Construction Special Trade Contractors, or 1731, Electrical Work: Comfort Systems USA, a large mechanical contractor, is filed under 1731.

How many plumbing businesses there are

County Business Patterns counted 111,207 establishments in 238220 in 2023, with 1,214,761 employees and an annual payroll of $89.5 billion, about $73,700 per employee. CBP can't split plumbers from HVAC contractors; both are inside the same code.

The top states are California (11,686), Florida (9,353), Texas (8,966), New York (7,061) and Pennsylvania (4,154). CBP counts locations with paid employees, so a franchise with ten branches counts ten times and a plumber working alone isn't counted. CBP 2023 uses NAICS 2017; 238220 didn't change in 2022.

SBA size standard

From 13 CFR 121.201, effective March 17, 2023 and unchanged in the eCFR as of 28 October 2026. Receipts are averaged over your latest five complete fiscal years and include the parts and materials you bill: SBA's receipts rule allows only the exclusions it lists, and materials aren't one (13 CFR 121.104).

Where the code is used

• Federal contracts. A contract that's mostly plumbing is solicited under 238220, because SBA classifies a procurement by the component with the largest share of its value (13 CFR 121.402). If a maintenance contract mixes several trades and none is half its value, SBA classifies it as Building and Property Specialty Trade Services under 238990 instead, so list that too if you bid on maintenance.
• Tax returns. Schedule C uses 238220, the same as NAICS.
• Insurers and lenders. They group plumbing with HVAC under 238220, so if your business is plumbing-only, say so in the description; the code alone doesn't tell them.

Finding plumbing companies

The best names come from state plumbing license files, where your state publishes them, and from city permit records, which show who pulled permits recently. For public companies, EDGAR lists SIC 1700 and SIC 1731 registrants, and plumbing distributors under SIC 5070:

The contractors here do far more HVAC and commercial mechanical work than residential plumbing. Residential plumbing is almost entirely private, owner-run firms, which a Bebop search such as residential plumbing companies in Atlanta with 10 to 50 employees and a service fleet can list with the reason each fits.

Worked example

Illustrative example. The business and figures are invented.

Bluewater Plumbing & Drain (bluewater.example) earned $4.8 million last year: repair and repipe work $2.9 million (60%), drain and sewer cleaning without installation $1.3 million (27%), and septic system installs $0.6 million (13%).

Its primary code is 238220 (SIC 1711). Drain cleaning is a secondary code, 561790, and septic installs are 238910. The mix matters for federal work: drain cleaning has a $9.0 million size standard and plumbing $19.0 million. With five-year average receipts of $4.1 million, Bluewater is small under all three.

For a seller, the lesson is the opposite: a list pulled only on 238220 includes every HVAC contractor and misses drain specialists coded 561790. Search both codes and filter on what the company says it does.

Next step: see how the trades fit together in the NAICS code for construction guide.