| Spectra Tech Group Ltd | Wholesale & retail | 2025 |
| Spectrum Building Services Limited | Construction | 2020 |
| Speed 6 Collections Ltd | Wholesale & retail | 2024 |
| Speed 6 Holdings Ltd | Real estate | 2024 |
| Speed 6 Investments Ltd | Real estate | 2024 |
| Speedy Fasteners Limited | Wholesale & retail | 2013 |
| Speedy Shift Ltd | Transport & logistics | 2025 |
| Speedy Wheels 2 Limited | Transport & logistics | 2025 |
| Spembly 11 Limited | Construction | 2021 |
| Spembly 17 Limited | Construction | 2021 |
| Spembly 19 Limited | Construction | 2021 |
| Spembly 23 Limited | Construction | 2019 |
| Spembly 3 Limited | Construction | 2020 |
| Spembly 6 Limited | Construction | 2019 |
| Spencer Care Solutions Limited | Professional & scientific | 2025 |
| Spencer Park (Block a) Freehold Limited | Other services | 2003 |
| Spencer Road Residents' Association Limited | Households | 1972 |
| Spencer Walk Residents Association Limited | Households | 1983 |
| Spencers Wood Apartments (Reading) Management Company Limited | Households | 2005 |
| SPG Training Academy Ltd | Education | 2018 |
| Spha Moving ADS Limited | Information & communication | 2016 |
| Sphaerica Limited | Wholesale & retail | 2016 |
| Sphere Apartments Limited | Real estate | 2021 |
| Spice & Vibes Central Ltd | Hospitality | 2025 |
| Spice Kitchen Surrey Limited | Hospitality | 2023 |
| Spice Land Croydon Ltd | Hospitality | 2018 |
| Spice of Brasil Limited | Arts & recreation | 2015 |
| Spices (Shirley) SS Ltd | Hospitality | 2019 |
| Spices Croydon Ltd | Hospitality | 2025 |
| Spicy Villa Limited | Hospitality | 2026 |
| Spiddi & Styl Ltd | Professional & scientific | 2011 |
| Spill & Clean Ltd | Administrative & support | 2025 |
| Spin 2 WIN Entertainments Limited | Arts & recreation | 2006 |
| Spinmedia Marketing Ltd | Information & communication | 2012 |
| Spiral Bytes Limited | Wholesale & retail | 2023 |
| Spiral Designs Limited | Manufacturing | 2023 |
| Spiral Direct Developments Limited | Wholesale & retail | 2006 |
| Spire Lifts Limited | Manufacturing | 2024 |
| Spires Supermarket Ltd | Wholesale & retail | 2016 |
| Spireswood Grange (Hurstpierpoint) Management Company Limited | Households | 2015 |
| Spitfire Community Project CIC | Real estate | 2026 |
| SPJ Climbing Three Limited | Arts & recreation | 2023 |
| SPK Services Limited | Wholesale & retail | 2015 |
| Splasharts C.I.C. | Arts & recreation | 2020 |
| Splat Decorating Ltd | Construction | 2002 |
| Splendid Care Limited | Administrative & support | 2012 |
| Splitsix Poker Ltd | Information & communication | 2025 |
| SPM Development Services Limited | Education | 2013 |
| SPN Retail Limited | Wholesale & retail | 2026 |
| Spookylady Ltd | Wholesale & retail | 2021 |
| Sport and Health Academy Limited | Arts & recreation | 2013 |
| Sporting Goals Limited | Arts & recreation | 2001 |
| Sports Elite Limited | Education | 2017 |
| Sportscom Media Limited | Administrative & support | 2000 |
| Spotless Cleaning and Maintenance Limited | Administrative & support | 2025 |
| Spotless Special Cleaning Services Limited | Administrative & support | 2018 |
| Spotlight Community Arts CIC | Information & communication | 2026 |
| Spotlight Events Limited | Administrative & support | 2026 |
| SPR3D Limited | Professional & scientific | 2018 |
| Sprimont Limited | Real estate | 2023 |
| Spring BEA Ltd | Real estate | 2020 |
| Spring Operations Limited | Real estate | 2015 |
| Spring Park Medical Centre Limited | Health & social care | 2013 |
| Spring Techlab Limited | Information & communication | 2024 |
| Springbank Management Limited | Households | 1991 |
| Springfield Court (Upminster) Management Limited | Households | 2021 |
| Springfield Global Properties Ltd | Real estate | 2019 |
| Springhill Care Limited | Health & social care | 2022 |
| Springhill Facility and Construction Management Services Ltd | Construction | 2024 |
| Springhill Well Being Community Interest Company | Education | 2023 |
| Springlands (Streatham) Management Co. Limited | Households | 1996 |
| Springmove Limited | Real estate | 2019 |
| Springview Holdco 1 Limited | Real estate | 2024 |
| Springview Holdco 2 Limited | Real estate | 2024 |
| Springview Investments Ltd | Real estate | 2016 |
| Springview Subco Limited | Real estate | 2024 |
| Spritu Ltd | Transport & logistics | 2022 |
| Sprucespace Property Management Limited | Households | 1991 |
| Spruceunit Property Management Limited | Households | 1991 |
| Spuddydis Ltd | Information & communication | 2024 |
| Spun Arrow Creative Limited | Professional & scientific | 2025 |
| Spurstowe Terrace RTM Company Limited | Households | 2014 |
| Spurz Autos Ltd | Wholesale & retail | 2018 |
| SPV Limited | Professional & scientific | 2019 |
| SQ Dwellings Limited | Real estate | 2018 |
| SQ Point Limited | Hospitality | 2010 |
| Sqrx Ltd | Information & communication | 2024 |
| Squadlead Management Consultants UK Limited | Real estate | 2021 |
| SQUAR3D SOLUT1ONS Ltd | Professional & scientific | 2025 |
| Square 74 Management Company Limited | Households | 2001 |
| Squires Court (Camberley) M.C. Limited | Households | 1999 |
| Squish Enterprises Ltd | Other services | 2018 |
| Sqwzl Limited | Information & communication | 2013 |
| SR Business Consultancy Services Limited | Professional & scientific | 2020 |
| SR Life Coaching Limited | Professional & scientific | 2018 |
| SR Logex Ltd | Wholesale & retail | 2026 |
| SR Prestige Valeting Services Limited | Administrative & support | 2020 |
| Sr&R Limited | Professional & scientific | 2016 |
| SR7 Ltd | Wholesale & retail | 2016 |
| Sraymax London Ltd | Construction | 2017 |