| SK5 Ltd | Real estate | 2023 |
| SK7 Properties Ltd | Real estate | 2024 |
| Skaci and Sons Limited | Construction | 2016 |
| Skakkos Limited | Administrative & support | 2014 |
| Skand Properties Ltd | Real estate | 2023 |
| Skar & Sons Group Ltd | Real estate | 2025 |
| Skat Logistics Ltd | Transport & logistics | 2017 |
| SKB Legal Ltd. | Professional & scientific | 2019 |
| SKC Pharma Ltd | Health & social care | 2025 |
| Skdh Limited | Real estate | 2021 |
| Sketch Limited | Hospitality | 2016 |
| SKF (U.K.) Limited | Manufacturing | 1910 |
| Skfi Limited | Financial services | 2023 |
| SKH Solutions Ltd | Wholesale & retail | 2021 |
| Skhan Food Ltd | Hospitality | 2025 |
| Skifteri Limited | Construction | 2025 |
| Skill Merchants Limited | Information & communication | 2013 |
| Skilled Electrical and IT Ltd | Construction | 2023 |
| Skillforge Global Ltd | Professional & scientific | 2025 |
| Skillshub Direct Limited | Wholesale & retail | 2018 |
| Skin & Clear Ltd | Other services | 2022 |
| Skin & Hair Manufacturing Hub Ltd | Manufacturing | 2011 |
| Skin House UK Ltd | Other services | 2021 |
| Skinastute Distribution Limited | Wholesale & retail | 2020 |
| Skinastute Limited | Other services | 2018 |
| Skint Ltd | Information & communication | 2011 |
| SKJ Healthcare Consulting Limited | Professional & scientific | 2015 |
| Skkzx Ltd | Wholesale & retail | 2026 |
| SKL Advisory Limited | Professional & scientific | 2025 |
| Skmotorz Ltd | Wholesale & retail | 2026 |
| Skoolwork Ltd | Other services | 2018 |
| SKP8 Limited | Wholesale & retail | 2025 |
| SKR Driving School Ltd | Education | 2026 |
| Skrb Services Ltd | Health & social care | 2024 |
| Skrt London Ltd | Wholesale & retail | 2022 |
| SKS Builders Ltd | Construction | 2023 |
| SKS Transport (UK) Ltd | Transport & logistics | 2013 |
| SKT Chaii Garden London Ltd | Wholesale & retail | 2025 |
| Sktrans Group Ltd | Transport & logistics | 2019 |
| Sky Autoz Ltd | Wholesale & retail | 2025 |
| Sky Computing Limited | Information & communication | 2014 |
| Sky Distributor Ltd | Wholesale & retail | 2023 |
| Sky Dunstable Cars Ltd | Transport & logistics | 2017 |
| Sky Grill Limited | Hospitality | 2026 |
| Sky Investments (UK) Limited | Real estate | 2013 |
| Sky Lence IT Ltd | Information & communication | 2026 |
| Sky Parade Limited | Hospitality | 2019 |
| Sky Tech Research Limited | Information & communication | 2026 |
| Sky Watch Security Services Limited | Construction | 2025 |
| Sky Worker Access Group Ltd | Construction | 2021 |
| Sky-Klean Services Ltd | Administrative & support | 2022 |
| SKY9 Ltd | Wholesale & retail | 2018 |
| Skylance Projects Limited | Real estate | 2024 |
| Skyline Assets Limited | Real estate | 2018 |
| Skyline Carz Ltd | Wholesale & retail | 2023 |
| Skyline Carzz Ltd | Wholesale & retail | 2026 |
| Skyline Propertylink Ltd | Real estate | 2020 |
| Skyline Roofers and Contractors Ltd | Construction | 2024 |
| Skyline Solicitors Ltd | Professional & scientific | 2024 |
| Skyline UK Services Ltd | Other services | 2026 |
| Skyline Vector Ltd | Construction | 2026 |
| Skylinebetterhomes Limited | Construction | 2025 |
| Skymax Limited | Arts & recreation | 2005 |
| Skyn by SIM Ltd. | Other services | 2023 |
| Skyrise Solutions Ltd | Construction | 2024 |
| Skyswood Management Limited | Households | 1978 |
| Skytech Commerce UK Ltd | Real estate | 2024 |
| Skyward Consulting Ltd | Professional & scientific | 2017 |
| Skywiings Ltd | Information & communication | 2024 |
| SL - Automotive Ltd | Wholesale & retail | 2020 |
| SL Couriers Limited | Transport & logistics | 2020 |
| SL HR Consultancy Ltd | Administrative & support | 2021 |
| SL Luton Limited | Professional & scientific | 2025 |
| SL SAI Ltd | Transport & logistics | 2021 |
| Slam Food Ltd | Hospitality | 2023 |
| Slamburger Luton Ltd | Hospitality | 2023 |
| Slap Sauce Ltd | Wholesale & retail | 2023 |
| Slarr Holdings Ltd | Financial services | 2023 |
| Slate Campaigns Limited | Professional & scientific | 2014 |
| Slawek's Custom Carpentry LDN Ltd | Construction | 2025 |
| Slayritefashion Ltd | Professional & scientific | 2023 |
| SLC Cleaning Ltd | Administrative & support | 2023 |
| Sleek Bedrooms Limited | Wholesale & retail | 2014 |
| Sleeproot Ltd | Wholesale & retail | 2025 |
| Sleeve Section Limited | Wholesale & retail | 2026 |
| SLG Locations Ltd | Real estate | 2025 |
| Slice Supply UK Ltd | Wholesale & retail | 2026 |
| Slice&Spice Limited | Hospitality | 2024 |
| Slim Charles Collectibles Ltd | Wholesale & retail | 2026 |
| Slings Logistics Ltd | Transport & logistics | 2026 |
| Sloane Property Services Limited | Construction | 2007 |
| Slotavio Limited | Information & communication | 2023 |
| SLS Security Solutions Ltd | Administrative & support | 2025 |
| Sls-Av Ltd | Wholesale & retail | 2023 |
| Slush and Sips Ltd | Wholesale & retail | 2019 |
| SLW Services Ltd | Professional & scientific | 2023 |
| SM Caring Services Limited | Health & social care | 2021 |
| SM CON Ltd Ltd | Construction | 2025 |
| SM Constructions Services Limited | Construction | 2021 |
| SM Consultants Ltd | Professional & scientific | 2022 |