| Senator Wholesale Ltd | Wholesale & retail | 2026 |
| SENDIT4ME Limited | Wholesale & retail | 2015 |
| Sendmate Technology CIC | Information & communication | 2025 |
| Sendora Ltd | Wholesale & retail | 2024 |
| Senior Software Services Limited | Information & communication | 2023 |
| Seniorcise Ltd | Health & social care | 2018 |
| Sennen Properties Limited | Real estate | 2018 |
| Sennovera Limited | Wholesale & retail | 2025 |
| Senol & Senol Ltd | Manufacturing | 2017 |
| Sensory Energy Ltd | Professional & scientific | 2012 |
| Sensory International Limited | Construction | 2002 |
| Sentiments (Horwich) Ltd | Wholesale & retail | 2003 |
| Sentinel Care Limited | Administrative & support | 2001 |
| Senttra Limited | Financial services | 2025 |
| Senvori Ltd | Wholesale & retail | 2025 |
| Seon PVT Ltd | Professional & scientific | 2022 |
| Seowizard Ltd | Information & communication | 2025 |
| SEP Rail Benefits Ltd | Administrative & support | 2023 |
| Septaria Limited | Professional & scientific | 2002 |
| Sequoia Homes Developments Limited | Real estate | 2021 |
| Sera Catering Limited | Hospitality | 2014 |
| Seraphic Parfums Ltd | Wholesale & retail | 2026 |
| Seraphize Ltd | Wholesale & retail | 2024 |
| Serava Holdings Ltd | Financial services | 2025 |
| Seren Collective Limited | Professional & scientific | 2026 |
| Serene Healthcare Ltd | Other services | 2016 |
| Serene Media Ltd | Information & communication | 2026 |
| Serene Solace CIC | Health & social care | 2024 |
| Serenity Birth and Baby Limited | Education | 2023 |
| Serenity Fireplaces Ltd | Wholesale & retail | 2012 |
| Serenity Healthcare Services Limited | Health & social care | 2019 |
| Serenity Pet Funeral and Cremation Services Ltd | Other services | 2025 |
| Serenity Pet Funeral Services Ltd | Water & waste | 2019 |
| Serenity Retail Services Limited | Other services | 2018 |
| Serenity Salon & Spa Limited | Other services | 2015 |
| Serenity Technology Ltd | Information & communication | 2022 |
| Serenity Technology Solutions Ltd | Information & communication | 2024 |
| Seriona Care Ltd | Administrative & support | 2026 |
| Serious Immigration Lawyers Limited | Professional & scientific | 2016 |
| Serious Law LLP | | 2010 |
| Sero Properties Limited | Real estate | 2021 |
| Serora Ltd | Wholesale & retail | 2026 |
| Serpent and Scythe Tattoo Ltd | Administrative & support | 2017 |
| Servicecal Limited | Other services | 1996 |
| Servicelabs Ltd | Information & communication | 2026 |
| Servicewood Limited | Information & communication | 2014 |
| Servilog 41 Private Ltd | Real estate | 2023 |
| SES People FM Limited | Administrative & support | 2025 |
| SES People Limited | Administrative & support | 2024 |
| SES T2P Serv Limited | Administrative & support | 2025 |
| SES T2P Services Ltd | Administrative & support | 2025 |
| SET & Style Limited | Professional & scientific | 2011 |
| SET Clean Limited | Other services | 2025 |
| SET to Move Properties Management Limited | Real estate | 2024 |
| Seth Law Limited | Professional & scientific | 2011 |
| Seth Liberty Ltd | Real estate | 2024 |
| Seth Properties & Management Ltd | Real estate | 2024 |
| Seudocode Ltd | Information & communication | 2020 |
| Sevaline Care Homes Limited | Health & social care | 2013 |
| Sevaline Holdings Limited | Financial services | 2020 |
| Sevaline Limited | Health & social care | 2006 |
| Seven 07 (UK) Limited | Wholesale & retail | 2007 |
| Seven Bees Ltd | Wholesale & retail | 2025 |
| Seven Direct Ltd | Hospitality | 2019 |
| Seven Lines Ltd | Hospitality | 2025 |
| Seven Skys IT Developers Limited | Information & communication | 2025 |
| SEVEN29 Limited | Transport & logistics | 2024 |
| Seventeen Minutes Limited | Wholesale & retail | 2021 |
| Seventh Philosophy Ltd | Wholesale & retail | 2025 |
| SEVENTY7 Management Limited | Arts & recreation | 2023 |
| SEW Simple Workwear Limited | Manufacturing | 2017 |
| Seymour Road Nursery Ltd | Health & social care | 2021 |
| SFA Advisory Limited | Financial services | 2025 |
| Sfet UK Limited | Wholesale & retail | 2021 |
| SFH Consultancy Limited | Education | 2002 |
| SFJ Holdings Limited | Real estate | 2018 |
| SFK Britania Ltd | Wholesale & retail | 2023 |
| Sfold Ltd | Wholesale & retail | 2025 |
| SFP Transport Services Ltd | Transport & logistics | 2026 |
| SFW Business Consultants Limited | Financial services | 2019 |
| SG Business Consultants Limited | Professional & scientific | 2013 |
| SG Elite Contracts Ltd | Construction | 2020 |
| SG Smart Investment Ltd | Real estate | 2019 |
| SG Toplinker Ltd | Wholesale & retail | 2026 |
| SG Trade Windows Limited | Construction | 2020 |
| SGB Drainage Limited | Water & waste | 2021 |
| Sgci (UK) Ltd | Administrative & support | 2024 |
| SGK AMZ Ltd | Wholesale & retail | 2024 |
| SGM Mortgages Ltd | Financial services | 2022 |
| SGS Productions Ltd | Information & communication | 2016 |
| Sgtm Ltd | Financial services | 2022 |
| SGW Homes Ltd | Real estate | 2014 |
| SH Automotive Transportation Ltd | Transport & logistics | 2025 |
| SH Bolton Traders Ltd | Wholesale & retail | 2026 |
| SH Consultancy (NW) Limited | Professional & scientific | 2025 |
| SH Dental Laboratory Ltd | Health & social care | 2018 |
| SH Financial Enterprises Limited | Financial services | 2011 |
| SH H K Limited | Administrative & support | 2019 |
| SH Process Ltd | Professional & scientific | 2023 |
| SH Residential Holdings Ltd | Real estate | 2026 |