| Smith Properties Limited | Real estate | 2012 |
| Smith Robinson Ltd | Financial services | 1979 |
| Smith Settle Printing & Bookbinding Limited | Manufacturing | 1987 |
| Smith Taylor Natural Products Limited | Manufacturing | 1995 |
| Smith Wessex Ltd | Information & communication | 2016 |
| Smith Worldwide Data Limited | Information & communication | 2022 |
| Smithfield Holdings | | 1992 |
| Smiths Commercials Limited | Wholesale & retail | 2024 |
| Smiths of Weston Ltd | Information & communication | 2016 |
| Smithurst Solutions Limited | Professional & scientific | 2020 |
| Smitin Hair Design Limited | Other services | 2013 |
| SMK Portfolio Holdings Ltd | Real estate | 2025 |
| SML Noble Investments Ltd | Construction | 2020 |
| SML Northern Limited | Construction | 2015 |
| SML Solutions Ltd | Administrative & support | 2012 |
| Smmmile Bristol Limited | Health & social care | 2022 |
| Smmmile Glasgow Limited | Health & social care | 2024 |
| Smmmile Leeds Limited | Health & social care | 2022 |
| Smmmile Newcastle Limited | Health & social care | 2022 |
| Smmmile Nottingham Limited | Health & social care | 2025 |
| Smmmile Shelfco Limited | Health & social care | 2022 |
| Smmmile Shelfco Two Limited | Health & social care | 2023 |
| Smoenterprise Ltd | Wholesale & retail | 2025 |
| Smoke N Timber Limited | Hospitality | 2026 |
| Smoke Signals Taqueria Ltd | Hospitality | 2025 |
| Smoke Vent Solutions International Ltd | Administrative & support | 2016 |
| Smokestack Cocktails Limited | Wholesale & retail | 2021 |
| Smola Transport Ltd | Transport & logistics | 2020 |
| Smooth Commercial Law Limited | Professional & scientific | 2016 |
| Smooth Industrial Products Limited | Wholesale & retail | 1992 |
| Smooth Operator (Corporate Events) Limited | Other services | 1994 |
| Smooth Track Solutions Ltd | Professional & scientific | 2020 |
| Smoothwall Limited | Information & communication | 2001 |
| Smoyo Ltd | Health & social care | 2014 |
| SMP Finance Ltd | Professional & scientific | 2025 |
| SMR Tradings (Yorkshire) Ltd | Hospitality | 2017 |
| Smrc Estate Ltd | Real estate | 2023 |
| Smrc Technologies Limited | Information & communication | 2022 |
| SMS Contract Services Ltd | Construction | 2016 |
| SMT Mobile & Computers Ltd | Wholesale & retail | 2023 |
| SMU Engineering Ltd | Professional & scientific | 2017 |
| Smudge Consultants Ltd | Professional & scientific | 2021 |
| Smuk (Leeds) Limited | Financial services | 2021 |
| Smuk (Properties) Limited | Financial services | 2021 |
| Smuve Global Ltd | Transport & logistics | 2023 |
| SMW Mottors Ltd | Administrative & support | 2011 |
| Smwr Ltd | Manufacturing | 2024 |
| SMY Parcels Limited | Transport & logistics | 2026 |
| SN Housing Ltd | Real estate | 2024 |
| SN Pharma Limited | Health & social care | 2022 |
| SNA Financials Limited | Professional & scientific | 2023 |
| SNA Suppliers Ltd | Wholesale & retail | 2024 |
| Snack in a Box Limited | Extraterritorial | 2018 |
| Snack in the Box Limited | Extraterritorial | 2018 |
| Snack Right Vending Solutions Ltd | Wholesale & retail | 2019 |
| Snack Snap Ltd | Administrative & support | 2025 |
| Snaith Engineering Associates Ltd | Construction | 2014 |
| Snap & Stock Ltd | Wholesale & retail | 2025 |
| Snap and FIX Ltd | Wholesale & retail | 2026 |
| Snap Diagnostics Ltd | Real estate | 2022 |
| Snap Enterprise Ltd | Wholesale & retail | 2024 |
| Snap Hook Limited | Wholesale & retail | 2025 |
| Snap Residential Ltd | Real estate | 2024 |
| Snap Your Moment Ltd | Arts & recreation | 2025 |
| Snapdragon Inc. Ltd | Manufacturing | 2019 |
| Snapdragon Properties Limited | Real estate | 2003 |
| Snappy Collective Ltd | Arts & recreation | 2023 |
| Snappy FOX Limited | Professional & scientific | 2024 |
| Snapsales Limited | Information & communication | 2017 |
| SNB Electronic Services Limited | Professional & scientific | 1998 |
| SNB Engineering Limited | Extraterritorial | 2003 |
| SNB Limited | Extraterritorial | 2007 |
| SNB Properties Ltd | Real estate | 2015 |
| SNC Commercial Group Limited | Financial services | 2026 |
| SND Electrical Limited | Construction | 2020 |
| Sneakers ETC Ltd | Administrative & support | 2016 |
| Sneaky Duck Limited | Information & communication | 2019 |
| Sneaky Rascal Games Ltd | Information & communication | 2024 |
| Sneh Property Investments Ltd | Real estate | 2021 |
| SNG Building Contractors Limited | Construction | 2003 |
| Sngodsblessings Limited | Health & social care | 2023 |
| Snivers Ltd | Real estate | 2023 |
| SNK (Leeds) Limited | Hospitality | 2011 |
| Snooze & Smile Ltd | Health & social care | 2026 |
| Snooze Best Beds Limited | Manufacturing | 2024 |
| Snow Camps Business Limited | Administrative & support | 2025 |
| Snow White Property Limited | Real estate | 2021 |
| Snowball 49 Ltd | Information & communication | 2022 |
| Snowball Media Ltd | Information & communication | 2022 |
| Snowden Leather Supplies Ltd | Manufacturing | 2005 |
| Snowdrop House (Roundhay) Management Company Limited | Households | 2006 |
| Snowed in Movie Ltd | Information & communication | 2024 |
| Snowflake Properties Ltd | Real estate | 2014 |
| Snowy Properties Ltd | Real estate | 2024 |
| Snoxer Holding Limited | Wholesale & retail | 2021 |
| SNR Electrics Limited | Construction | 2020 |
| SNS Detailing Ltd | Administrative & support | 2022 |
| SNS Leeds Ltd | Health & social care | 2021 |
| SNT (UK) Limited | Information & communication | 2003 |
| SNT Assets (UK) Limited | Information & communication | 2013 |