| SME Graduate Employment Ltd | Administrative & support | 2020 |
| Smed Electrical Design Limited | Construction | 2004 |
| Smed Group Ltd | Wholesale & retail | 2022 |
| Smedley Interiors & Property Services Ltd | Construction | 2025 |
| Smellie Savage Computers Limited | Information & communication | 1999 |
| Smelly Werewolf Films Ltd | Information & communication | 2020 |
| Smeraldo Properties Ltd | Real estate | 2024 |
| SMF Compliance Ltd | Professional & scientific | 2023 |
| SMF Financial Management Ltd | Professional & scientific | 2020 |
| SMF Metal Finishes Ltd | Manufacturing | 2024 |
| SMH Enterprises Limited | Real estate | 1997 |
| SMI Investment Holdings UK Ltd | Real estate | 2020 |
| Smile Care 4U Ltd | Health & social care | 2013 |
| Smile Centre (Boston) Limited | Health & social care | 2010 |
| Smile Centre (Gainsborough) Limited | Health & social care | 2025 |
| Smile Centre (Grimsby) Limited | Health & social care | 2024 |
| Smile Centre (HDC) Limited | Health & social care | 2026 |
| Smile Centre (Lincoln) Limited | Health & social care | 2025 |
| Smile Centre (Louth) Limited | Health & social care | 2026 |
| Smile Centre (Scunthorpe) Limited | Health & social care | 2024 |
| Smile Centre (Syston) Limited | Health & social care | 2026 |
| Smile Centre (Yorkshire) Limited | Health & social care | 2024 |
| Smile Foster Care Limited | Health & social care | 2013 |
| Smile Grill Nottingham Limited | Hospitality | 2026 |
| Smile Reach Limited | Professional & scientific | 2024 |
| Smile Studio Walk in Centre Limited | Health & social care | 2017 |
| Smiles by AMJ Limited | Health & social care | 2025 |
| Smiles Risk Solutions Ltd | Financial services | 2020 |
| Smileys Home & Gift Limited | Wholesale & retail | 2008 |
| Smillie COX & Co Ltd | Real estate | 2025 |
| Smillie K9 Services Ltd. | Other services | 2020 |
| Smite Farms Limited | Agriculture & fishing | 2015 |
| Smith & Jones Property Ltd | Real estate | 2026 |
| Smith & Radford Ltd | Wholesale & retail | 2022 |
| Smith & Wright Coffee Co LLP | | 2023 |
| Smith Abodes Ltd | Real estate | 2023 |
| Smith and Bignall Ltd | Hospitality | 2025 |
| Smith Architecture Ltd | Professional & scientific | 2019 |
| Smith Catering Ltd | Hospitality | 2025 |
| Smith Consulting Engineers Limited | Professional & scientific | 2014 |
| Smith Cookson Accountants Limited | Professional & scientific | 2003 |
| Smith Cookson Financial Services Limited | Professional & scientific | 2003 |
| Smith DE Wint Limited | Information & communication | 1996 |
| Smith Grayson Limited | Administrative & support | 2006 |
| Smith Natural Solutions Limited | Professional & scientific | 2024 |
| Smith Student Properties Limited | Real estate | 2020 |
| Smith&Eve Ltd | Hospitality | 2024 |
| Smith's Bookeeping & Accountancy Services Limited | Professional & scientific | 2001 |
| Smithfield Buildings TIB Street RTM Company Limited | Households | 2026 |
| Smithfields (Telford) Limited | Hospitality | 2025 |
| Smithform Ltd | Construction | 2016 |
| Smithkin Limited | Financial services | 2023 |
| Smiths Jewellers (Nottm) Ltd | Wholesale & retail | 2017 |
| Smiths Plumbing, GAS & Renewables Limited | Construction | 2026 |
| Smithwell Ltd | Professional & scientific | 2013 |
| Smithy's Smoke Shack Ltd | Wholesale & retail | 2020 |
| Smith’S Property Services & Maintenance Limited | Construction | 2022 |
| Smixon Ltd | Other services | 2008 |
| SMJ Garden Services Limited | Administrative & support | 2002 |
| SMK Investment Management Ltd | Real estate | 2016 |
| SML Wealth Ltd | Real estate | 2020 |
| Smlbiz Limited | Professional & scientific | 2011 |
| SMM Building Solutions Ltd | Construction | 2022 |
| SMM Property Holdings Ltd | Real estate | 2023 |
| Smnd Limited | Wholesale & retail | 2025 |
| Smnexpress Ltd | Hospitality | 2026 |
| Smns Limited | Health & social care | 2002 |
| Smokealot Ltd | Wholesale & retail | 2025 |
| Smokehouse Grill Events Ltd | Hospitality | 2025 |
| Smokeybeats Ltd | Information & communication | 2022 |
| Smoosh Holdings Limited | Financial services | 2024 |
| Smooth Aesthetics by Kelly Ltd | Other services | 2020 |
| Smooth Heating Ltd | Construction | 2024 |
| Smooth Ride Driving School Ltd | Education | 2025 |
| SMR Media Productions Ltd | Wholesale & retail | 2019 |
| Smret Limited | Transport & logistics | 2024 |
| Smriti Ltd | Real estate | 2025 |
| Smrtworx Limited | Wholesale & retail | 2025 |
| SMS - Smart Made Simple Limited | Professional & scientific | 2018 |
| SMS Builders UK Limited | Construction | 2024 |
| SMS Electronics Limited | Manufacturing | 2002 |
| SMS Kitchens Ltd. | Wholesale & retail | 2005 |
| SMS Smart Ventures Limited | Professional & scientific | 2018 |
| Smtideswell Ltd | Construction | 2018 |
| Smudge Squad Ltd | Administrative & support | 2025 |
| Smujtrading Ltd | Wholesale & retail | 2025 |
| Smurfit Westrock Bristol Ltd | Manufacturing | 1986 |
| Smurfit Westrock Consumer Packaging Limited | Manufacturing | 2013 |
| Smurfit Westrock Consumer Packaging UK Limited | Manufacturing | 1991 |
| Smurfit Westrock Packaging Machinery Limited | Manufacturing | 2003 |
| Smw-Autoblok Telbrook Limited | Manufacturing | 1993 |
| Smwhere Limited | Wholesale & retail | 2023 |
| Smyrna Commerce Ltd | Wholesale & retail | 2023 |
| Smythe Heating & Plumbing Ltd | Construction | 2022 |
| SN Consultancy and Support Services Ltd | Professional & scientific | 2026 |
| SN Global Trading Ltd | Wholesale & retail | 2025 |
| SN Nottingham Ltd | Real estate | 2020 |
| SN Supporting Services Limited | Health & social care | 2022 |
| SN Taxi Rentals Ltd | Administrative & support | 2026 |
| SNA Total Building Maintenance Limited | Construction | 2015 |