| Storer Electrical Communications Limited | Construction | 2023 |
| Stradywear Limited | Wholesale & retail | 2024 |
| Straight UP AI Limited | Information & communication | 2026 |
| Strategic Support Solutions Ltd | Administrative & support | 2026 |
| Striker TEC Ltd | Manufacturing | 2024 |
| Stronghands Ltd | Real estate | 2023 |
| STS Structural Engineering Ltd | Professional & scientific | 1991 |
| Studio Flora Ltd | Wholesale & retail | 2025 |
| Study Location Limited | Education | 2021 |
| Stylesparkle Wade Ltd | Wholesale & retail | 2024 |
| Summit Render Supplies London Limited | Construction | 2021 |
| Sunbeams Childcare Limited | Education | 2002 |
| Sunny Barhey Limited | Real estate | 2026 |
| Sunrise Networking Limited | Information & communication | 2014 |
| Supastrikers WEL HAT Ltd | Arts & recreation | 2022 |
| Super Engineering Ltd | Wholesale & retail | 2012 |
| Supplied and Fitted UK Limited | Administrative & support | 2015 |
| Suppro Ltd | Wholesale & retail | 2025 |
| Supreme Carpet Care (MK) Ltd | Administrative & support | 2016 |
| Sure Shift Motors Ltd | Wholesale & retail | 2026 |
| Suretest-Solutions Ltd | Manufacturing | 2021 |
| Surewinpath Limited | Information & communication | 2024 |
| Surrey Pharma Ltd | Manufacturing | 2012 |
| SV Grounds Limited | Construction | 2015 |
| Sweepsmart Limited | Administrative & support | 2018 |
| Sweet Spaces Limited | Real estate | 2021 |
| Sweets Without Ltd | Wholesale & retail | 2018 |
| Swiftsystem Limited | Information & communication | 1984 |
| Swim Shady Limited | Wholesale & retail | 2026 |
| SY Stander Limited | Financial services | 2016 |
| Sycamore Living Limited | Administrative & support | 2016 |
| Sykose Limited | Wholesale & retail | 2013 |
| Systime Properties Ltd | Real estate | 2021 |
| T & J Fire & Security Limited | Administrative & support | 2010 |
| T & J Fire Alarms Limited | Financial services | 1988 |
| T D & H Limited | Other services | 2015 |
| T J Fire Limited | Extraterritorial | 2015 |
| T-Mobile (UK) Limited | Professional & scientific | 2002 |
| T-Mobile (UK) Retail Limited | Professional & scientific | 1992 |
| T-Mobile International Limited | Professional & scientific | 2001 |
| T-Mobile International UK Pension Trustee Limited | Financial services | 2010 |
| T-Mobile Limited | Professional & scientific | 2002 |
| T. & J. Fire Limited | Administrative & support | 1973 |
| TA Property Rentals Ltd | Real estate | 2023 |
| Tafe Services Ltd | Information & communication | 2015 |
| Takestock Valuers Ltd | Professional & scientific | 2000 |
| Talia Marketing Ltd | Information & communication | 2026 |
| Talk-In-Herts Counselling Services C.I.C. | Health & social care | 2011 |
| Talon Security Systems Ltd | Wholesale & retail | 2026 |
| Tanksafe South Ltd | Transport & logistics | 2025 |
| Tapesilver Limited | Administrative & support | 2004 |
| Taptaf.Com Ltd | Health & social care | 2014 |
| Tarmaci Driving Services Ltd | Transport & logistics | 2011 |
| TAS Holdings Group Ltd. | Professional & scientific | 2019 |
| TAS Property Holdings Ltd | Real estate | 2019 |
| Tasen Consulting Ltd | Professional & scientific | 2023 |
| Tashes'N'Tails Limited | Wholesale & retail | 2008 |
| Taste of Africa Food and Culture CIC | Education | 2025 |
| Taste of Asia Ltd | Hospitality | 2025 |
| Tatum-Rose Limited | Hospitality | 2025 |
| Tawny Properties FIC Limited | Real estate | 2026 |
| Tawny Properties LLP | | 2020 |
| TC55 Investments Limited | Real estate | 2024 |
| TDN Service Limited | Other services | 2014 |
| Tdnc Care Group Limited | Health & social care | 2026 |
| TEACHINGHOW2S Ltd | Education | 1998 |
| Tecat Ltd | Information & communication | 2021 |
| Tech Tiger Group Ltd | Information & communication | 2021 |
| Tech Zion Limited | Information & communication | 2011 |
| Technovate Consulting Limited | Information & communication | 2021 |
| Tecna Solutions Ltd | Wholesale & retail | 2025 |
| Teesport (GP) Limited | Administrative & support | 2008 |
| TEL Tech Installations Ltd | Information & communication | 2001 |
| Templeton Broadcast Installations Limited | Information & communication | 2008 |
| Tempsford TEN Ltd | Professional & scientific | 2019 |
| TEN Distribution Ltd | Information & communication | 2008 |
| Terrick Investments Limited | Real estate | 2025 |
| Tesco Atrato (1LP) Limited | Administrative & support | 2009 |
| Tesco Atrato (GP) Limited | Administrative & support | 2009 |
| Tesco Atrato (Nominee 1) Limited | Administrative & support | 2009 |
| Tesco Atrato (Nominee 2) Limited | Administrative & support | 2009 |
| Tesco Atrato (Nominee Holdco) Limited | Administrative & support | 2009 |
| Tesco Atrato Depot Propco Limited | Administrative & support | 2009 |
| Tesco Blue (3LP) Limited | Administrative & support | 2016 |
| Tesco Blue (GP) Limited | Administrative & support | 2006 |
| Tesco Blue (Nominee 1) Limited | Professional & scientific | 2006 |
| Tesco Blue (Nominee 2) Limited | Professional & scientific | 2006 |
| Tesco Blue (Nominee Holdco) Limited | Professional & scientific | 2006 |
| Tesco Coral (GP) Limited | Administrative & support | 2008 |
| Tesco Coral (Nominee) Limited | Administrative & support | 2008 |
| Tesco Corporate Treasury Services PLC | Professional & scientific | 2013 |
| Tesco Depot Propco Limited | Administrative & support | 2008 |
| Tesco Distribution Holdings Limited | Professional & scientific | 1996 |
| Tesco Distribution Limited | Transport & logistics | 1994 |
| Tesco Dorney (1LP) Limited | Administrative & support | 2012 |
| Tesco Dorney (GP) Limited | Administrative & support | 2012 |
| Tesco Dorney (Nominee 1) Limited | Administrative & support | 2012 |
| Tesco Dorney (Nominee 2) Limited | Administrative & support | 2012 |
| Tesco Dorney (Nominee Holdco) Limited | Administrative & support | 2012 |
| Tesco Employees' Share Scheme Trustees Limited | Professional & scientific | 1993 |