| Slawston Investments Ltd | Financial services | 2014 |
| Slawston Limited | Financial services | 2014 |
| Slawston Properties Ltd | Real estate | 2014 |
| Slaynrise Design Ltd | Wholesale & retail | 2020 |
| Slayvend Ltd | Wholesale & retail | 2025 |
| SLB 2024 Limited | Arts & recreation | 2024 |
| SLB Distribution and Promotion Services Limited | Administrative & support | 2004 |
| SLC Cleaning Services Ltd | Administrative & support | 2023 |
| SLC Property Maintenance Ltd | Administrative & support | 2021 |
| SLC Property Management (Leicester) Ltd | Real estate | 2018 |
| SLC Property Renovations Ltd | Construction | 2021 |
| SLE Merchant Ltd | Construction | 2025 |
| Sleath Holdings Ltd | Financial services | 2022 |
| Sleep Styler Ltd | Professional & scientific | 2021 |
| Sleepcare Clinics Ltd | Health & social care | 2021 |
| Sleepless Marshmallows Ltd | Arts & recreation | 2022 |
| Sleepytime Beds Ltd | Wholesale & retail | 2022 |
| Slewof Limited | Professional & scientific | 2013 |
| Sleys Carrier Ltd | Transport & logistics | 2022 |
| SLH Planning Solutions Ltd | Other services | 2016 |
| Slice Finance Technologies Limited | Information & communication | 2025 |
| Slick Digital Ltd | Information & communication | 2016 |
| Slick Logic Ltd | Information & communication | 2010 |
| Slick Trade Limited | Wholesale & retail | 2024 |
| Slide Works Ltd | Manufacturing | 2023 |
| Slimmer Testing Solutions Group Holdings Limited | Professional & scientific | 2005 |
| Sline Marketing Management Ltd | Other services | 2025 |
| SLJ 21 Limited | Manufacturing | 2021 |
| SLJ Developments Limited | Real estate | 2002 |
| SLL Property Ltd | Real estate | 2023 |
| SLM Percival Holdings Ltd | Financial services | 2019 |
| SLM Percival Ltd | Agriculture & fishing | 2019 |
| Slmro Limited | Wholesale & retail | 2022 |
| Sloane Exports Ltd | Wholesale & retail | 2019 |
| Sloane's Hair and Beauty Salon Ltd | Other services | 2024 |
| Slosad Limited | Transport & logistics | 2017 |
| Slosh Media Ltd | Professional & scientific | 2024 |
| Slough Vans Ltd | Wholesale & retail | 2023 |
| SLS Builders (Leic) Ltd | Construction | 2024 |
| SLS Linen & Laundry Solutions Ltd | Administrative & support | 2018 |
| SLS Services Limited | Construction | 2019 |
| SLT Trustees Limited | Professional & scientific | 1977 |
| Slup Ltd | Wholesale & retail | 2026 |
| Slurp Kahvi Ltd | Wholesale & retail | 2020 |
| SLW Psychology Limited | Health & social care | 2021 |
| SLY Community Arts Limited | Manufacturing | 1997 |
| SLY Property Ltd | Real estate | 2025 |
| Slyde Holdings Limited | Financial services | 2019 |
| SM & V Sharma Management & Leadership Consultants Limited | Professional & scientific | 2016 |
| SM 90 Ltd | Professional & scientific | 2025 |
| SM Athletic Limited | Arts & recreation | 2017 |
| SM Candle Studio Ltd | Wholesale & retail | 2023 |
| SM Comms Limited | Construction | 2021 |
| SM Electric ENG Ltd | Construction | 2025 |
| SM Emporium Ltd | Wholesale & retail | 2024 |
| SM Enterprises Trading Ltd | Health & social care | 2021 |
| SM ER Ltd | Wholesale & retail | 2025 |
| SM Life Care Ltd | Health & social care | 2022 |
| SM Private Care Ltd | Health & social care | 2021 |
| SM Properties (Leicester) Limited | Real estate | 2004 |
| SM Property Services Leicester Ltd | Real estate | 2022 |
| SM Quality Consulting Limited | Professional & scientific | 2025 |
| SM Reviews Limited | Administrative & support | 2012 |
| SM Robinson Construction Limited | Construction | 2014 |
| SM SK Medical Ltd | Health & social care | 2016 |
| SM UK Courier Ltd | Transport & logistics | 2025 |
| SM Veloce Systems Ltd | Wholesale & retail | 2025 |
| SM Vision Solutions Ltd | Wholesale & retail | 2025 |
| SM2 Ltd | Real estate | 2022 |
| SMA Estate Holdings Limited | Real estate | 2012 |
| SMA Estate Maintenance Limited | Real estate | 2012 |
| Smach Design Ltd | Professional & scientific | 2017 |
| Smah Real Estate Limited | Real estate | 2025 |
| Smahh Constructions Ltd | Construction | 2024 |
| Smahh Properties Ltd | Real estate | 2024 |
| Small ARC Services Ltd | Professional & scientific | 2023 |
| Small Contractor Solutions Limited | Administrative & support | 2025 |
| Small Steps to Allah Ltd | Information & communication | 2021 |
| Smallfusion Ltd | Information & communication | 2017 |
| Smallman & SON Limited | Manufacturing | 2000 |
| Smallsteps Group Ltd | Manufacturing | 2020 |
| Smamz Limited | Wholesale & retail | 2021 |
| Smart Accountancy & Tax Limited | Professional & scientific | 2014 |
| Smart Accounting and Consultancy Ltd | Professional & scientific | 2021 |
| Smart Adobe Ltd | Other services | 2025 |
| Smart and Quick Transports Services Ltd | Transport & logistics | 2024 |
| Smart Auto Body Works Ltd | Wholesale & retail | 2026 |
| Smart Bolster Limited | Professional & scientific | 2025 |
| Smart Budget Cars UK Ltd | Wholesale & retail | 2021 |
| Smart Business Recovery Limited | Professional & scientific | 2018 |
| Smart Bustle Limited | Professional & scientific | 2025 |
| Smart Buy (Bakewell) Limited | Professional & scientific | 2008 |
| Smart Buy Ltd | Wholesale & retail | 2024 |
| Smart Choice Living Ltd | Real estate | 2024 |
| Smart Communications (Leicester) Limited | Wholesale & retail | 2018 |
| Smart Cook Ltd | Hospitality | 2018 |
| Smart Double Glazing Ltd | Manufacturing | 2021 |
| Smart Dragon Limited | Wholesale & retail | 2008 |
| Smart Driving Academy Limited | Education | 2022 |
| Smart DT Solutions Ltd | Wholesale & retail | 2021 |