| Smart Constantin Limited | Transport & logistics | 2018 |
| Smart Construction Solutions Ltd | Construction | 2024 |
| Smart Construction Work Ltd | Construction | 2024 |
| Smart Creations and Security Services Limited | Construction | 2021 |
| Smart Energy AID Ltd | Construction | 2025 |
| Smart Haulage Academy Ltd | Other services | 2024 |
| Smart Home Surveyors Limited | Professional & scientific | 2012 |
| Smart Homes Ltd | Construction | 2025 |
| Smart Investments (PVT) Ltd | Real estate | 2021 |
| Smart IT Solutions Ltd | Information & communication | 2017 |
| Smart Link Accessories Ltd | Wholesale & retail | 2026 |
| Smart Linkx Ltd | Information & communication | 2023 |
| Smart Logistics Manager Ltd | Information & communication | 2019 |
| Smart Network NG Limited | Information & communication | 2024 |
| Smart Properties Developments Limited | Real estate | 2018 |
| Smart Properties Harehills Ltd | Real estate | 2020 |
| Smart Reamer Drilling Systems Ltd | Mining & quarrying | 2009 |
| Smart Selling Ltd | Wholesale & retail | 2022 |
| Smart Service Management Ltd | Information & communication | 2014 |
| Smart Services Limited | Information & communication | 2008 |
| Smart Skills Builder Ltd | Construction | 2023 |
| Smart Tech Engineers Ltd | Construction | 2025 |
| Smart Testing Solutions Ltd | Information & communication | 2017 |
| Smart Vend Ltd | Wholesale & retail | 2026 |
| Smart View Home Improvements Ltd | Construction | 2025 |
| Smartbird Europe Ltd | Wholesale & retail | 2015 |
| Smartclean Pro Ltd | Administrative & support | 2026 |
| SMARTDROPSHIP25 Limited | Wholesale & retail | 2025 |
| Smartdry Technologies Limited | Information & communication | 2026 |
| Smartech Motors Ltd | Wholesale & retail | 2024 |
| Smartech Security Limited | Construction | 2016 |
| Smartenergy House Ltd | Construction | 2025 |
| Smartflow Pneumatics Limited | Energy | 2020 |
| Smarthire Recruitment UK Limited | Information & communication | 2022 |
| Smartj Ltd | Wholesale & retail | 2021 |
| Smartly.Io Solutions Ltd | Information & communication | 2018 |
| Smartmove Enterprises Limited | Real estate | 2020 |
| Smartmove Homes Limited | Health & social care | 1999 |
| Smartone Tech UK Limited | Other services | 2017 |
| Smarts Cleaners Ltd | Administrative & support | 2025 |
| Smartscratch Ltd | Wholesale & retail | 2022 |
| Smartview Property Ltd | Real estate | 2019 |
| Smartwave Innovations Ltd | Information & communication | 2024 |
| Smartzit Ltd | Information & communication | 2019 |
| Smaze Ltd | Real estate | 2024 |
| Smbh Properties Limited | Real estate | 2026 |
| Smcg Networks Ltd | Professional & scientific | 2026 |
| SMD Design and Build Ltd | Construction | 2025 |
| SMG Builders & Developers Ltd | Construction | 2019 |
| Smiit Ltd | Information & communication | 2012 |
| Smile Align Planning Ltd | Information & communication | 2023 |
| Smile Care (Cornwall) Ltd | Health & social care | 2013 |
| Smile Care (Plymouth City) Limited | Health & social care | 2013 |
| Smile Care 24 Limited | Health & social care | 1999 |
| Smile Care Aberdeen Limited | Health & social care | 2013 |
| Smile Care Boscombe Ltd | Health & social care | 2021 |
| Smile Care Cippenham Ltd | Health & social care | 2012 |
| Smile Care Devon Ltd | Health & social care | 2025 |
| Smile Care Dorset Ltd | Health & social care | 2012 |
| Smile Care Eastleigh Ltd | Administrative & support | 2019 |
| Smile Care Gosport Ltd | Administrative & support | 2020 |
| Smile Care Havant Ltd | Administrative & support | 2019 |
| Smile Care Holbury Ltd | Administrative & support | 2020 |
| Smile Care Hold 21 Ltd | Administrative & support | 2021 |
| Smile Care North Ltd | Health & social care | 2012 |
| Smile Care Oxford Ltd | Health & social care | 2024 |
| Smile Care Paignton Ltd | Health & social care | 2012 |
| Smile Care Plymouth Ltd | Health & social care | 2012 |
| Smile Care Portsmouth Ltd | Administrative & support | 2020 |
| Smile Care Redruth Ltd | Health & social care | 2024 |
| Smile Care South PPP Limited | Administrative & support | 2018 |
| Smile Care Suffolk Ltd | Health & social care | 2026 |
| Smile Care Swanage Ltd | Administrative & support | 2020 |
| Smile Care Swindon Limited | Health & social care | 2012 |
| Smile Care Torbay Ltd | Health & social care | 2025 |
| Smile Care Totton Ltd | Administrative & support | 2020 |
| Smile Care Twyford Limited | Health & social care | 2012 |
| Smile Care Woolston Ltd | Administrative & support | 2020 |
| Smile Dental Ltd | Administrative & support | 2019 |
| Smile Dental Services Ltd | Health & social care | 2025 |
| Smile Engineer Ltd | Health & social care | 2026 |
| Smile Services London Ltd | Administrative & support | 2020 |
| Smilecart Limited | Wholesale & retail | 2025 |
| Smiles Cart Limited | Wholesale & retail | 2026 |
| Smiles Homes UK Ltd | Real estate | 2016 |
| Smith & Massen Limited | Health & social care | 2014 |
| Smith FX Ltd | Information & communication | 2024 |
| Smitham Residences Ltd | Real estate | 2021 |
| Smiths Business Information Services Limited | Information & communication | 1996 |
| Smiths Group Holdings Netherlands B.V. | | 2008 |
| Smooth Feathers Limited | Professional & scientific | 2014 |
| Smoothflow Controls Limited | Extraterritorial | 2011 |
| SMP Houses Limited | Real estate | 2024 |
| Smpk Limited | Manufacturing | 2016 |
| Smrg Properties Ltd | Real estate | 2025 |
| Smriti IT Solutions Limited | Information & communication | 2021 |
| SMS Holdings (UK) Limited | Real estate | 2001 |
| SMS Traders Ltd | Wholesale & retail | 2016 |
| Smyk Properties Ltd | Real estate | 2018 |
| SN & B Ltd | Transport & logistics | 2022 |