| Skystalker Limited | Information & communication | 2018 |
| Skystay Suites Ltd | Real estate | 2024 |
| Skyway Property Ltd | Real estate | 2026 |
| SL Electrics MK Limited | Construction | 2025 |
| SL Evolution Limited | Financial services | 2018 |
| SL Hair & Beauty Ltd | Other services | 2025 |
| SL Music Limited | Information & communication | 2018 |
| SL Trucking Ltd | Extraterritorial | 2014 |
| SL2 Group Ltd | Wholesale & retail | 2018 |
| Slamjam Ltd | Information & communication | 2005 |
| Slater & Slater PUB Co Ltd | Hospitality | 2020 |
| Slater Hogg Mortgages Limited | Financial services | 2001 |
| Slav K9 Ltd | Administrative & support | 2022 |
| Slayhouse Ltd | Other services | 2019 |
| SLD Test Solutions Limited | Professional & scientific | 2012 |
| Sleekay Limited | Administrative & support | 2021 |
| Sleep Penguin Limited | Wholesale & retail | 2022 |
| Sleepworks Ltd | Health & social care | 2020 |
| Slengra Limited | Information & communication | 2012 |
| SLG Office Furniture & Interiors Ltd. | Wholesale & retail | 2014 |
| SLH Plumbing and Heating Limited | Construction | 2018 |
| Slice of Skye Ltd | Construction | 2025 |
| Slick Financial Solutions Ltd | Financial services | 2009 |
| Slick the Dragon Ltd | Information & communication | 2010 |
| Slika Media Limited | Information & communication | 2013 |
| Sling Aircraft (UK) Ltd. | Manufacturing | 2016 |
| Slingstone Limited | Information & communication | 2001 |
| Slmartin Limited | Professional & scientific | 2004 |
| Slotconsults Ltd | Information & communication | 2023 |
| SLQ Skills Limited | Wholesale & retail | 2005 |
| SLS Accounts & Tax Limited | Professional & scientific | 2022 |
| SLS Interiors Ltd | Professional & scientific | 2020 |
| SLT MK Ltd | Hospitality | 2025 |
| SLT Motors Ltd | Wholesale & retail | 2024 |
| Sluice Box Media Group Ltd | Financial services | 2019 |
| SLV Properties Ltd | Real estate | 2019 |
| SM & RSB Ventures Limited | Hospitality | 2025 |
| SM Benefits Ltd | Wholesale & retail | 2026 |
| SM Car Rental Didcot Ltd | Wholesale & retail | 2026 |
| SM Carpentry Services Ltd | Construction | 2021 |
| SM Concierge Ltd | Professional & scientific | 2026 |
| SM IDC Limited | Professional & scientific | 2023 |
| SM Manufacturing Holdings Limited | Wholesale & retail | 2009 |
| SM Pharma Ltd | Wholesale & retail | 2022 |
| SM Rewards Ltd | Professional & scientific | 2025 |
| SM Studio Ltd | Information & communication | 2022 |
| SM Traderz Ltd | Wholesale & retail | 2026 |
| Sm@Rket Limited | Wholesale & retail | 2020 |
| SMA Dental Limited | Health & social care | 2023 |
| Small & Smart Limited | Information & communication | 2017 |
| Small Crocodile Ltd | Arts & recreation | 2018 |
| Small Stream Limited | Education | 2024 |
| Small Works Business Solutions Ltd | Professional & scientific | 2026 |
| Smaller Stream Limited | Real estate | 2025 |
| Smallford Land Limited | Financial services | 2012 |
| Sman MK Limited | Transport & logistics | 2021 |
| Smart 13 Limited | Real estate | 2017 |
| Smart Adviser Ltd | Professional & scientific | 2018 |
| Smart Build Homes Chesham Limited | Real estate | 2022 |
| Smart Build Homes Falmouth Limited | Real estate | 2024 |
| Smart Build Homes Limited | Construction | 2019 |
| Smart Choice Garage Ltd | Wholesale & retail | 2020 |
| Smart City MK CIC | Information & communication | 2022 |
| Smart Consulting Solutions Limited | Professional & scientific | 2023 |
| Smart Finance Hub Ltd | Education | 2026 |
| Smart FIX Auto Bodyworks Limited | Wholesale & retail | 2026 |
| Smart Grid Energy Solutions Ltd | Energy | 2024 |
| Smart Holder Solutions Limited | Manufacturing | 2017 |
| Smart Living Designs Limited | Construction | 2007 |
| Smart Lockers Installs Ltd | Construction | 2025 |
| Smart Move Estate Agents Ltd | Real estate | 2010 |
| Smart Nestlife Ltd | Wholesale & retail | 2024 |
| Smart Paint Crash Repair Ltd | Wholesale & retail | 2003 |
| Smart Project Solutions Ltd | Construction | 2025 |
| Smart Reactors UK Limited | Manufacturing | 2024 |
| Smart Recruitment 16 Ltd | Administrative & support | 2022 |
| Smart Solder Ltd | Other services | 2024 |
| Smart Solutions 4 ALL Limited | Wholesale & retail | 2013 |
| Smart Solutions Consultancy Limited | Professional & scientific | 2022 |
| Smart Stick Ltd | Other services | 2024 |
| Smart TEK Solutions Limited | Information & communication | 2010 |
| Smart UK Automotive Ltd | Wholesale & retail | 2021 |
| SMART1ELECTRICAL&GAS Ltd | Construction | 2025 |
| Smartbidet Ltd | Other services | 2024 |
| Smartbin Ltd | Other services | 2024 |
| Smartbrains Solutions Ltd | Information & communication | 2017 |
| Smartek WR Enterprises Ltd | Wholesale & retail | 2025 |
| Smarter Financial Planning Ltd | Financial services | 2014 |
| Smarter Inventories Ltd | Information & communication | 2015 |
| Smarter Property Services London Ltd | Professional & scientific | 2019 |
| Smartfit Construction Ltd | Construction | 2020 |
| Smartflux Energy Ltd | Other services | 2024 |
| Smartgraze Ltd | Other services | 2024 |
| Smartjacks Limited | Other services | 2014 |
| Smartkey Ltd | Other services | 2016 |
| Smartlancs Limited | Information & communication | 2017 |
| Smartoven Ltd | Other services | 2024 |
| Smartpill Ltd | Other services | 2024 |
| Smartrix Systems Ltd | Other services | 2023 |
| Smarttrend Venture Limited | Real estate | 2021 |