| Street Solution Services Ltd | Professional & scientific | 2023 |
| Streetbox London CIC | Manufacturing | 2020 |
| Stride Removals Ltd | Transport & logistics | 2020 |
| Strike Sports Management Limited | Professional & scientific | 2022 |
| Strikeforce Scaffolding Limited | Construction | 2017 |
| Stronghold Anchor Limited | Administrative & support | 2024 |
| Strongway Nominees Limited | Real estate | 1963 |
| Studio 152 (Borehamwood) Management Company Limited | Households | 2005 |
| Studio 152 Estate (Borehamwood) Management Company Limited | Households | 2005 |
| Studio 152 NO. 1 (Borehamwood) Management Company Limited | Households | 2007 |
| Studio 152 the Lair (Borehamwood) Management Company Limited | Households | 2007 |
| Studio Piot Ltd | Information & communication | 2025 |
| Suffolk Prestige Ltd | Wholesale & retail | 2025 |
| Sugardown Limited | Professional & scientific | 2023 |
| SUI Investments Limited | Real estate | 1982 |
| Sukanya Catering Company Ltd | Hospitality | 2025 |
| Sully & Cully Ltd | Information & communication | 2023 |
| Sultan & Dervis Ltd | Financial services | 2024 |
| Sunderland Road (Sandy) Management Company Limited | Households | 2013 |
| Sunny Days Nursery & Preschool Ltd | Education | 2014 |
| Sunoctal Ltd | Information & communication | 2014 |
| Sunshine Crew Limited | Construction | 2022 |
| Superfly Media Limited | Professional & scientific | 2020 |
| Superior Foods (Mexborough) Limited | Wholesale & retail | 1960 |
| Supreme Security Solutions Services Ltd | Administrative & support | 2019 |
| Sussex Fields (One) Management Company Limited | Households | 1993 |
| Sustainable Growth Studio Limited | Professional & scientific | 2025 |
| Suzan Management Ltd | Real estate | 2024 |
| SVS Cargo Ltd | Transport & logistics | 2023 |
| Swallow House Print Limited | Administrative & support | 1997 |
| Swallowfields (Nantwich) Management Company Limited | Households | 2004 |
| Swan Food Products Limited | Wholesale & retail | 1987 |
| Swan Foods International Limited | Wholesale & retail | 1978 |
| Swanlea Estates Limited | Real estate | 2009 |
| Swanlea SUB Ltd | Real estate | 2024 |
| Swansley Properties Limited | Real estate | 2026 |
| Swim Safety Ltd | Arts & recreation | 2010 |
| Swinbourne Grove Management Company Limited | Households | 2021 |
| Swinford Haulage Limited | Transport & logistics | 2015 |
| Sycamore Chase Flat Management Company Limited | Households | 2002 |
| Sycamore Manor (Whittle-Le-Woods) Management Company Limited | Households | 2021 |
| Sycamore Walk (Clitheroe) Management Company Limited | Households | 2017 |
| Syke Gardens (Tingley) Management Company Limited | Households | 1999 |
| Symonds Court Residents Limited | Households | 2006 |
| Synergy Commercial Lighting Limited | Manufacturing | 2018 |
| Synergy Lifts Limited | Manufacturing | 2014 |
| Syntero Scientific Limited | Professional & scientific | 2026 |
| Szerelmey (UK) Holdings Limited | Professional & scientific | 2014 |
| Szerelmey (UK) Limited | Construction | 2012 |
| T & R Builders Limited | Construction | 2009 |
| T & S Studios Ltd | Construction | 2018 |
| T D Eldridge Ltd | Construction | 2020 |
| T N S Estates Limited | Real estate | 2019 |
| T Stewart Investments Limited | Financial services | 2025 |
| T.M.K. Property Holdings Ltd | Real estate | 2026 |
| Tabforce Limited | Professional & scientific | 2007 |
| Tabley Green Management Company Limited | Households | 2017 |
| Tabley Park Residents Management Company Limited | Households | 2020 |
| Tagit Services Limited | Information & communication | 2008 |
| Tail Mill (Merriott) Residents Management Company Limited | Households | 2016 |
| Tailor Made Packaging Limited | Administrative & support | 2000 |
| Tailored Protection Limited | Financial services | 2013 |
| Talent Acquisition Bureau Ltd | Administrative & support | 2025 |
| Talented People TV Ltd | Administrative & support | 2017 |
| Talo Barbers Ltd | Other services | 2022 |
| Tamarinds Two (Colchester) Management Company Limited | Households | 2007 |
| Tamin Court Management Limited | Households | 1995 |
| Tanesaos Trading Co. Ltd | Wholesale & retail | 2019 |
| Tanrad Ltd | Transport & logistics | 2026 |
| Tapmedic IP Limited | Wholesale & retail | 2017 |
| Taprack Limited | Extraterritorial | 2019 |
| Tasty Cottage Ltd | Hospitality | 2024 |
| Tawnymoor Limited | Real estate | 1984 |
| Taylor's Chase Management Company Limited | Households | 2018 |
| Taylored Drainage Solutions Ltd | Water & waste | 2020 |
| TB Spark Ltd | Construction | 2017 |
| TCK IT Engineer Ltd | Information & communication | 2019 |
| TDC PR Limited | Professional & scientific | 2013 |
| TDD Hertfordshire Ltd | Construction | 2023 |
| TDD North & East London Ltd | Construction | 2023 |
| TDE London Limited | Construction | 2023 |
| TDS (Berkshire) Limited | Water & waste | 2021 |
| TDS Limited | Transport & logistics | 2008 |
| Team CG Limited | Professional & scientific | 2012 |
| Teardrop Communications Limited | Professional & scientific | 2015 |
| TEC Designs Ltd | Information & communication | 2025 |
| Tech Knowledge Consulting Ltd | Information & communication | 2025 |
| Techdelivery Ltd | Professional & scientific | 2018 |
| Techrubix Limited | Information & communication | 2025 |
| Teckna Ltd | Information & communication | 1995 |
| Teckwell Ltd | Administrative & support | 2000 |
| Tecworx Limited | Administrative & support | 2020 |
| Tejohn Limited | Real estate | 2014 |
| Tekky Football Ltd | Education | 2023 |
| Telefone Resources (UK) Ltd | Information & communication | 2004 |
| Tellisford Limited | Professional & scientific | 2003 |
| Tellisford UK Limited | Professional & scientific | 2008 |
| Temple Manufacturing Company Limited | Manufacturing | 2000 |
| TEN Talents Financial Stewardship Ltd | Professional & scientific | 2021 |
| Tendie Healthcare Limited | Health & social care | 2025 |