| Scrambler Digital Ltd | Information & communication | 2025 |
| Screaming Gecko Digital Ltd | Extraterritorial | 2023 |
| Screen Squirrel Limited | Information & communication | 2024 |
| Scsg Motorsport Limited | Arts & recreation | 2022 |
| Sculpture Active Ltd | Wholesale & retail | 2021 |
| Scuttle Skins Ltd | Manufacturing | 2024 |
| SD - Developments (Anglia) Ltd | Construction | 2024 |
| SD Fibre Consultants Ltd | Professional & scientific | 2024 |
| SD Fixing Ltd | Construction | 2025 |
| SD Legacy Properties Ltd | Real estate | 2026 |
| SD Medical Aesthetics Ltd | Health & social care | 2023 |
| SD Pharm Services Limited | Professional & scientific | 2023 |
| SD Solutions Midlands Ltd | Construction | 2025 |
| SDA Solutions Ltd | Information & communication | 2024 |
| SDD Properties Ltd | Construction | 2026 |
| Sdfx Trading Limited | Wholesale & retail | 2026 |
| Seabridge Ssas Limited | Professional & scientific | 2021 |
| Seabridge Ssas Trustees Limited | Professional & scientific | 2021 |
| Seafield Systems Consulting Limited | Information & communication | 2015 |
| Seagrass Projects Limited | Construction | 2024 |
| Sealed Media Management Ltd | Information & communication | 2023 |
| Seamans Group Limited | Financial services | 2021 |
| Search Eagle Ltd | Information & communication | 2022 |
| Search Ventures Ltd | Information & communication | 2017 |
| Searchnexus Ltd | Information & communication | 2025 |
| Seaside Towns Economic Partnership Development Company Ltd | Other services | 2012 |
| Seasider Projects Ltd | Administrative & support | 2010 |
| Seaton Cards Limited | Other services | 2019 |
| SEB V Margiotta Management Services Limited | Professional & scientific | 2026 |
| SEC2 Alarms Limited | Extraterritorial | 2023 |
| SEC2 FM Limited | Extraterritorial | 2021 |
| SEC2 Logistics Limited | Extraterritorial | 2019 |
| Secina Limited | Transport & logistics | 2010 |
| Second Address Group Holdings Ltd | Financial services | 2026 |
| Second Address Property Management Ltd | Real estate | 2026 |
| Second Step NW Limited | Administrative & support | 2019 |
| Secret Sauce Consulting Limited | Professional & scientific | 2024 |
| Section 59 Club Ltd | Other services | 2025 |
| Secure Radio Communications Limited | Wholesale & retail | 2026 |
| Securefleet (UK) Limited | Other services | 2006 |
| Securehands Recruitment Ltd | Administrative & support | 2025 |
| Securict.Net Limited | Information & communication | 2007 |
| Security Audio LLP | | 2017 |
| Security Consultants and Mitigators Ltd | Administrative & support | 2024 |
| Security Solutions International Ltd | Administrative & support | 2018 |
| Sedoxy Ltd | Arts & recreation | 2026 |
| Seesh-El Ltd | Real estate | 2024 |
| Seguro Holdings Limited | Real estate | 2026 |
| Segventa Data Extraction Limited | Manufacturing | 2026 |
| Selby Environmental Limited | Other services | 2025 |
| Select Installation Engineers Ltd | Construction | 2004 |
| Select Office Furniture Limited | Administrative & support | 2008 |
| Select Vanilla Trading Co Ltd | Wholesale & retail | 2026 |
| Selena Trans Logistik Ltd | Transport & logistics | 2022 |
| Selene Holden Holdings Limited | Financial services | 2016 |
| Selfound Ltd | Information & communication | 2025 |
| Selftute Ltd | Information & communication | 2020 |
| Seller Performance Ltd | Professional & scientific | 2011 |
| Sellercross Ltd | Wholesale & retail | 2025 |
| Selling Online Support Ltd | Professional & scientific | 2015 |
| Sellology Limited | Education | 2015 |
| Sellology Sales Training Ltd | Education | 2026 |
| Sellwave Audio Ltd | Wholesale & retail | 2025 |
| SEM Properties & Investments Ltd. | Real estate | 2023 |
| Sempergens Limited | Professional & scientific | 2020 |
| SEN Legal Limited | Professional & scientific | 2003 |
| Sencolo Ltd | Education | 2023 |
| Send a Dog a Bone Ltd | Wholesale & retail | 2020 |
| Sendat | Education | 2011 |
| Sendat Trading | Education | 2023 |
| Sengupta Medical Services Limited | Health & social care | 2017 |
| Senguru CIC | Information & communication | 2026 |
| Senirol Ltd | Administrative & support | 2024 |
| Senovos Ltd | Professional & scientific | 2025 |
| Senq Limited | Hospitality | 2020 |
| Sens Nutrition Limited | Agriculture & fishing | 2010 |
| Sensaré Well-Being Ltd | Manufacturing | 2024 |
| Sent With Art Ltd | Wholesale & retail | 2020 |
| Sentinel Defenders Network Ltd | Other services | 2024 |
| Sentinel Networked Limited | Wholesale & retail | 2026 |
| Sentinel Protocol Limited | Information & communication | 2026 |
| Sentium X Ltd | Information & communication | 2026 |
| Sentos Group Ltd | Construction | 2024 |
| Sentrix Risks Ltd | Professional & scientific | 2026 |
| SEO Service Care Ltd | Information & communication | 2025 |
| Seoglide Limited | Professional & scientific | 2025 |
| Sequorent Interaction LAB Ltd | Information & communication | 2026 |
| Seraphine Global UK Ltd | Wholesale & retail | 2026 |
| Serapid Limited | Construction | 2004 |
| Serbyro Ltd | Transport & logistics | 2024 |
| Seren Aviation Ltd | Transport & logistics | 2026 |
| Serene Harmony Homes Ltd | Construction | 2025 |
| Serene Vibrations Limited | Information & communication | 2020 |
| Serenesage Trading Co., Ltd | Wholesale & retail | 2025 |
| Serenity Cleaning Services Limited | Administrative & support | 2019 |
| Seriously FUN Limited | Arts & recreation | 2005 |
| Seriously FUN Swimming Schools LLP | | 2008 |
| Sermi Media NET Ltd | Information & communication | 2026 |
| Serotonin Ltd | Wholesale & retail | 2020 |
| Serp Squad Ltd | Information & communication | 2024 |