| SMG Mortgage & Protection Services Ltd | Financial services | 2025 |
| SMG Painting Ltd | Construction | 2019 |
| SMH Hospitality Limited | Hospitality | 2026 |
| SMI Property Investment Ltd | Real estate | 2024 |
| Smig Holdings Ltd | Administrative & support | 2021 |
| Smile & Implant Ltd | Health & social care | 2014 |
| Smile Bright Ltd | Health & social care | 2006 |
| Smile Centre Ltd | Health & social care | 2009 |
| Smile Design Centre Limited | Health & social care | 2009 |
| Smile Design Suite and Aesthetics by Shireen Ltd | Health & social care | 2021 |
| Smile Health Holdings Limited | Real estate | 2023 |
| Smile Health Ltd | Administrative & support | 2009 |
| Smile Perfections Limited | Health & social care | 2019 |
| Smile Together | Education | 2015 |
| Smile Zeal Ltd | Health & social care | 2018 |
| Smile Zone Ltd | Health & social care | 2007 |
| Smileart Dental Laboratory Limited | Manufacturing | 2023 |
| Smiles 4 Orphans Ltd | Wholesale & retail | 2024 |
| Smiles by Gurms Ltd | Health & social care | 2020 |
| Smiles Nurseries Ltd | Health & social care | 2016 |
| Smiles of Quorn Limited | Education | 2018 |
| Smileshare Ltd | Information & communication | 2021 |
| Smilexcel Limited | Education | 2018 |
| Smith & Dorrien Ltd | Information & communication | 2020 |
| Smith & Johnson Heating and Technical Solutions Limited | Construction | 2009 |
| Smith 'N' Sons Ltd | Wholesale & retail | 2023 |
| Smith Blackmore Property Ltd | Construction | 2022 |
| Smith Brothers (Leicester) Limited | Manufacturing | 1907 |
| Smith Brothers Stores Limited | Wholesale & retail | 1969 |
| Smith by Smyth Ltd | Professional & scientific | 2022 |
| Smith Enterprises Ltd | Financial services | 2024 |
| Smith Hannah Tax Limited | Professional & scientific | 2019 |
| Smith Plus Consultancy Ltd | Professional & scientific | 2026 |
| Smith Plus Properties Ltd | Real estate | 2025 |
| Smith Prestige Motors Ltd | Wholesale & retail | 2026 |
| Smith Sample Cases Limited | Extraterritorial | 1959 |
| Smith's Jewellers Leicester Limited | Wholesale & retail | 2024 |
| Smithaleigh Haulage Ltd | Transport & logistics | 2014 |
| Smithincott Ltd | Transport & logistics | 2015 |
| Smiths (the T.V. Specialists) 1975 Limited | | 1975 |
| Smithsclean Ltd | Administrative & support | 2024 |
| SMJ Lead Limited | Administrative & support | 2025 |
| SMK Accountancy Limited | Professional & scientific | 2008 |
| Smks Properties Ltd | Real estate | 2023 |
| SML Consulting (Leicester) Ltd | Financial services | 2025 |
| SML Geospatial Ltd | Professional & scientific | 2001 |
| SML Geotechnical Ltd | Extraterritorial | 2023 |
| SML Group Limited | Professional & scientific | 2015 |
| SML Laboratories Ltd | Professional & scientific | 2024 |
| SML Payroll Limited | Extraterritorial | 2015 |
| SML Praksh Trading Limited | Wholesale & retail | 2023 |
| SML Subsidence Ltd | Professional & scientific | 2007 |
| SML Surveys Limited | Extraterritorial | 2015 |
| Smms Developments Limited | Construction | 2017 |
| Smoke & Fire Curtains Limited | Manufacturing | 2009 |
| Smoking Helps Ltd | Wholesale & retail | 2026 |
| Smoky Fades Ltd | Other services | 2025 |
| Smooth 7 Construction Ltd | Construction | 2020 |
| Smooth Contracting Ltd | Administrative & support | 2025 |
| Smooth Street Limited | Administrative & support | 2014 |
| SMP Property LLP | | 2016 |
| SMR Electrical Ltd | Energy | 2024 |
| SMR Solutions Limited | Information & communication | 2026 |
| Smrk Assets Limited | Real estate | 2025 |
| SMS Builders Leicester Ltd | Construction | 2021 |
| SMS Estates Limited | Real estate | 2018 |
| SMS UK Hospitality Limited | Hospitality | 2023 |
| Smsdd Limited | Financial services | 2020 |
| SMT Unique Interiors Ltd | Manufacturing | 2021 |
| SMV Building Services Limited | Construction | 2015 |
| SMV PVT Ltd | Health & social care | 2013 |
| Smys Healthcare Ltd | Health & social care | 2015 |
| Smyth & Co Luxury Consultants Ltd | Professional & scientific | 2019 |
| Smyth & Co NOT for Profit Ltd | Professional & scientific | 2022 |
| SN Consultancy Services Limited | Health & social care | 2007 |
| SN Express Ltd | Wholesale & retail | 2026 |
| SNA Express Ltd | Transport & logistics | 2021 |
| Snack 'N' Roll Limited | Hospitality | 2019 |
| Snack Shop Leics Ltd | Wholesale & retail | 2025 |
| Snackco Ltd | Hospitality | 2019 |
| Snailvans Ltd. | Manufacturing | 2013 |
| Snam Global Ltd | Wholesale & retail | 2026 |
| Snap Apparel Limited | Manufacturing | 2019 |
| Snap N Load Ltd | Wholesale & retail | 2025 |
| Snap on Autos Limited | Wholesale & retail | 2023 |
| Snapmarketing Enterprise Ltd | Transport & logistics | 2025 |
| Snaps.Digital Ltd | Information & communication | 2025 |
| Snapshoot Photography Studio Ltd | Professional & scientific | 2025 |
| Snapshot Live Ltd | Manufacturing | 2025 |
| Snapwell Photo & Video Limited | Professional & scientific | 2014 |
| Snargate Ltd | Transport & logistics | 2015 |
| Snarstone Ltd | Transport & logistics | 2015 |
| Snatched by Shuv Ltd | Arts & recreation | 2024 |
| SNB Consulting Services Ltd | Professional & scientific | 2024 |
| SNB Trading Limited | Wholesale & retail | 2020 |
| SNB Vision Care Ltd | Health & social care | 2020 |
| SNC Exterior Cleaning Ltd | Administrative & support | 2025 |
| SND Streetwear Ltd | Manufacturing | 2025 |
| Sndfx Beats Limited | Administrative & support | 2025 |
| Sneaker Fresh UK Ltd | Other services | 2020 |