| Slowsoft Ltd | Professional & scientific | 2023 |
| SLP Building Services Ltd | Construction | 2025 |
| SLP Independent Living Ltd | Health & social care | 2024 |
| SLP Unity CIC | Health & social care | 2025 |
| Slyc Ltd | Transport & logistics | 2026 |
| SM Caterers Ltd | Hospitality | 2019 |
| SM Fight Club Ltd | Administrative & support | 2025 |
| SM Marketing Recruitment UK Ltd | Professional & scientific | 2025 |
| SM Plumbing & Heating (SW) Ltd | Construction | 2025 |
| SM Premium Cleaning Limited | Administrative & support | 2026 |
| Smaf Kids Ltd | Arts & recreation | 2023 |
| Small Car Centre Limited | Wholesale & retail | 2025 |
| Smalley Wellbeing Limited | Other services | 2021 |
| Smart Café Chelmsford Ltd | Hospitality | 2021 |
| Smart Caring Limited | Health & social care | 2021 |
| Smart Decision Paintwork Repair Specialists Ltd | Wholesale & retail | 2019 |
| Smart Endeavours Ltd | Manufacturing | 2017 |
| Smart Fuse Limited | Construction | 2021 |
| Smart Movers Limited | Transport & logistics | 1992 |
| Smart Pick Limited | Administrative & support | 2019 |
| Smart Raspberry Cookery School LLP | | 2015 |
| Smart Raspberry Limited | Education | 2011 |
| Smart Showers Limited | Wholesale & retail | 1995 |
| Smart Start Consulting Ltd | Education | 2023 |
| Smart Village Melksham Ltd | Other services | 2026 |
| Smart-Courier (Swindon) Ltd | Transport & logistics | 2021 |
| Smartcom UK LLP | | 2017 |
| Smarter 10 Ltd | Financial services | 2024 |
| Smarter 11 Ltd | Financial services | 2025 |
| Smarter 12 Ltd | Financial services | 2025 |
| Smarter 2 Ltd | Administrative & support | 2022 |
| Smarter 3 Ltd | Administrative & support | 2023 |
| Smarter 4 Ltd | Administrative & support | 2023 |
| Smarter 5 Ltd | Administrative & support | 2023 |
| Smarter 6 Ltd | Administrative & support | 2023 |
| Smarter 7 Ltd | Administrative & support | 2023 |
| Smarter 8 Ltd | Administrative & support | 2023 |
| Smarter 9 Ltd | Financial services | 2024 |
| Smarter Capital Ltd | Financial services | 2023 |
| Smarter Capital Partners LLP | | 2022 |
| Smarter Ecommerce Ltd | Financial services | 2024 |
| Smarter Export Ltd | Wholesale & retail | 2023 |
| Smarter Health & Wellbeing Ltd | Financial services | 2026 |
| Smarter Media Group Ltd | Administrative & support | 2023 |
| Smarter Packaging Ltd | Financial services | 2025 |
| Smartgreen Property Management Limited | Administrative & support | 1992 |
| Smartrak Facilities Management Ltd | Administrative & support | 2009 |
| Smartrak Holdings Limited | Real estate | 2019 |
| Smartsmash Ltd | Information & communication | 2026 |
| Smartway West Limited | Construction | 2022 |
| Smash Three (Swindon) Limited | Hospitality | 2019 |
| Smdljd Property Holdings Limited | Real estate | 2024 |
| SME Engineering Ltd | Professional & scientific | 2023 |
| SME Solutions Ltd | Professional & scientific | 2026 |
| Smileabout Limited | Health & social care | 2011 |
| Smith and Floyd Hospitality Limited | Hospitality | 2025 |
| Smith Brothers Property Holdings Ltd | Real estate | 2023 |
| Smiths Drywall Ltd | Construction | 2024 |
| Smiths News Distribution Limited | Professional & scientific | 2013 |
| Smiths News Holdings Limited | Professional & scientific | 2001 |
| Smiths News Instore Limited | Professional & scientific | 1997 |
| Smiths News Investments Limited | Professional & scientific | 2009 |
| Smiths News PLC | Professional & scientific | 2004 |
| Smiths News Trading Limited | Wholesale & retail | 1929 |
| Smiths Roofing Contractors Limited | Construction | 2000 |
| Smiths TCG Supplies Ltd | Wholesale & retail | 2025 |
| Smokinly Good BBQ Ltd | Hospitality | 2024 |
| Smorgasbord IT Limited | Information & communication | 2007 |
| SMP Decorators Ltd | Construction | 2003 |
| Smriti Cloths Limited | Wholesale & retail | 2026 |
| SMS Parcels Deliveries Ltd | Transport & logistics | 2023 |
| Smudges Wiltshire Ltd | Other services | 2023 |
| Smugmutts Limited | Wholesale & retail | 2019 |
| SMW Consulting Engineers Limited | Professional & scientific | 2009 |
| SMW777 Ltd | Transport & logistics | 2022 |
| SN Heating & Plumbing Ltd | Construction | 2019 |
| SN Refrigeration Ltd | Manufacturing | 2021 |
| SN Waste Removal Ltd | Water & waste | 2025 |
| SN1 Car Wash Ltd | Administrative & support | 2025 |
| SN1 Customs Limited | Wholesale & retail | 2019 |
| SN1 Promotions Ltd | Arts & recreation | 2024 |
| SN21 Watches Ltd | Wholesale & retail | 2023 |
| SN25 Sales Agency Limited | Wholesale & retail | 2022 |
| SN4 Ltd | Other services | 2018 |
| SN4 Venue Ltd | Hospitality | 2022 |
| SN5 Catering Ltd | Hospitality | 2024 |
| SN5 Food Services Ltd | Hospitality | 2024 |
| Snackerz Ltd | Hospitality | 2022 |
| Snackza Ltd | Wholesale & retail | 2025 |
| Snakeshead K9 Ltd | Wholesale & retail | 2025 |
| Snappy Van Hire Ltd | Administrative & support | 2021 |
| Snapyai Ltd | Information & communication | 2025 |
| Snds Estates Limited | Real estate | 2020 |
| Sneddon Homes Ltd | Real estate | 2021 |
| Snes Swindon Ltd. | Wholesale & retail | 2009 |
| Snipe Trading Limited | Information & communication | 2023 |
| SNM Electrical Ltd | Manufacturing | 2008 |
| Snowshill Services Ltd | Wholesale & retail | 2021 |
| Snvr Trans Ltd | Transport & logistics | 2016 |
| SNY Trans Ltd | Transport & logistics | 2019 |