| Payne Plumbing & Piping Inc | C36 | 2014 | Active |
| Peg Enterprise Inc | C36 + B, C10 | 2015 | Active |
| Peninsula Plumbing | C36 | 2025 | Active |
| Performance Automation Solutions Inc | C36 + B, C7, C10 +2 | 2010 | Active |
| Permanent Solutions Plumbing & Drain | C36 | 2024 | Active |
| Pipe Core Solutions Inc | C36 | 2025 | Active |
| Pipe Hero Plumbing Inc | C36 | 2025 | Active |
| Pipe Trades | C36 + C20 | 2014 | Renew by Nov 30, 2026 |
| Plumb Loco Inc | C36 | 1998 | Active |
| Plumberbill.Com | C36 | 2007 | Active |
| Plumbing & Air Star Heating | C36 + A, B, C20 | 2019 | Active |
| Plumbing Essentials | C36 | 2026 | Active |
| Plumbing Rehab Inc | C36 | 2026 | Active |
| Plumbtech LLC | C36 | 2026 | Active |
| PMC Construction Partners Inc | C36 + B, C21, C53 | 2026 | Active |
| Point Loma Electric, Plumbing, Heating & Air | C36 + B, C10, C20 | 2009 | Active |
| Powers Plumbing | C36 + A, B, C10 +1 | 2006 | Active |
| Precision Plumbing Solutions Inc | C36 | 2026 | Active |
| Premier Plumbing San Diego | C36 | 2025 | Active |
| Pronto Plumbing & Drains Inc | C36 | 2004 | Active |
| Protec Building Services | C36 + ASB, B, C33 | 2002 | Active |
| Pure Pro Plumbing | C36 + B | 2025 | Active |
| Quality Plumbing Services | C36 | 2010 | Active |
| Quick Water Heater Company | C36 + B | 2011 | Active |
| R D Plumbing | C36 | 2017 | Active |
| Ram Plumbing & Leak Detection | C36 | 2022 | Active |
| Ramona Pacific Plumbing Inc | C36 | 2007 | Active |
| Ranbar Plumbing Contractors Inc | C36 + A | 2004 | Active |
| Rapid Restorations Inc | C36 + B | 2009 | Active |
| Rayne Dealership Corporation | C36 | 2002 | Active |
| RDZ Plumbing And Drains | C36 | 2018 | Renew by Nov 30, 2026 |
| Re-Store Services | C36 + B | 2023 | Active |
| Reasonable Drain & Plumbing Repair Inc | C36 | 2005 | Active |
| Repipe On Time And Plumbing | C36 | 2024 | Renew by Nov 30, 2026 |
| RJC Compliance Ca Inc | C36 | 2026 | Active |
| RMR Plumbing Inc | C36 | 2018 | Active |
| Roasa Plumbing Inc | C36 + C10 | 2025 | Active |
| Robertson Mechanical Inc | C36 + B, C20 | 2010 | Active |
| Rockstar Plumbing Heating And Air Inc | C36 + B, C20 | 2013 | Active |
| Roper Rick Plumbing Inc | C36 | 1995 | Active |
| Route One Plumbing Inc | C36 | 2010 | Active |
| Saffa Contracting Co | C36 + B, C20 | 2025 | Active |
| Same Day Heating Cooling & Plumbing | C36 + C10, C20 | 2025 | Active |
| Same Day Heating Cooling Plumbing | C36 + C10, C20 | 2019 | Active |
| San Diego Backflow Testing | C36 + C4, C12, C34 +1 | 2019 | Active |
| San Diego Plumbing & Drain Solutions Inc | C36 | 2026 | Active |
| San Diego Pure Water | C36 | 2022 | Active |
| San Diego Sewer Contractor 911 Inc | C36 + A, B | 2023 | Active |
| Sandiegoplumbing.Com | C36 | 2025 | Active |
| Save Plumbing Co | C36 | 2025 | Active |
| Scotts Drain And Plumbing Inc | C36 | 2004 | Active |
| Scylla Plumbing & Drains Inc | C36 | 2025 | Active |
| SD Plumbing Solutions Inc | C36 | 2024 | Active |
| SDS Plumbing Inc | C36 | 2022 | Active |
| Seacoast Plumbing Inc | C36 | 2026 | Active |
| Servpro Of Centre City / Uptown | C36 + ASB, B, C21 +2 | 2018 | Active |
| Sheer Quality Plumbers | C36 | 2022 | Active |
| Sherwood Mechanical Inc | C36 + A | 2003 | Active |
| Shugarman's Bath | C36 + B | 2019 | Active |
| Smart Dry Restoration | C36 + B | 2020 | Active |
| Spahr Plumbing Inc | C36 | 1988 | Active |
| SPC Plumbing | C36 + B | 2021 | Active |
| Steam Diego | C36 + D35 | 1981 | Active |
| Steele Plumbing | C36 | 2024 | Active |
| Strong Construction Co Inc | C36 + B, C8, C9 +7 | 1974 | Active |
| Sun Plumbing | C36 | 2009 | Active |
| Sun West Plumbing | C36 | 1995 | Active |
| Super Drain Bros Inc | C36 | 2022 | Active |
| Superior Residential Plumbing | C36 | 2024 | Active |
| Switch Your Fixture | C36 + B, C10 | 2020 | Active |
| Switch Your Fixture Inc | C36 + C10 | 2024 | Active |
| T Kino's Plumbing Corp | C36 | 2024 | Active |
| Tankless Service Pro LLC | C36 | 2023 | Active |
| Tankless Works Inc | C36 | 2025 | Active |
| Tha Heating Air & Plumbing | C36 + A, B, C20 +1 | 1997 | Active |
| The White Glove Guys, Plumbing Drains Heating Air Conditioning | C36 + B, C10, C20 +1 | 1987 | Active |
| Thielman Properties Inc | C36 + B | 2007 | Active |
| Timeless Development | C36 + A, B, C6 +6 | 2000 | Active |
| Tom Dinardo Plumbing Inc | C36 | 2004 | Renew by Dec 31, 2026 |
| Top Quality Plumbing Inc | C36 | 1992 | Renew by Dec 31, 2026 |
| Top Rated Home Remodel And Design | C36 + B, C20 | 2022 | Active |
| Tradegroup Improvements | C36 + B | 2021 | Active |
| Trident Pipelining LLC | C36 | 2024 | Active |
| Trinidad Plumbing Inc | C36 | 2026 | Active |
| Troy Plumbing And Repairs Inc | C36 + C42 | 2018 | Renew by Dec 31, 2026 |
| Trustworthy Plumbing Inc | C36 | 2021 | Active |
| Twin Plumbing & Drain Cleaning Inc | C36 | 2001 | Active |
| Tyler Holding Group LLC | C36 + B | 2025 | Active |
| Unimaster Inc | C36 + C10, C20 | 2002 | Active |
| United Electric Plumbing Heating & Air | C36 + B, C10, C20 | 1976 | Active |
| US Stone & Cabinets Inc | C36 + C6, C54 | 2010 | Active |
| USA Jetting Drain Pros Inc | C36 | 1998 | Active |
| Utmost Plumbing | C36 | 2024 | Active |
| Valstrong Plumbing Inc | C36 | 2024 | Active |
| Vessel Plumbing Inc | C36 | 2020 | Active |
| Village Plumbing & Heating | C36 | 2005 | Active |
| Viper Plumbing & Pipe Lining Inc | C36 | 2026 | Active |
| Water Purification Systems Inc | C36 + C55 | 2016 | Active |
| Wave Plumbing | C36 | 2005 | Active |
| West County Mechanical | C36 + B, C4, C20 | 2008 | Active |