| SW Finance Ltd | Financial services | 2013 |
| Swaledale Homes Limited | Hospitality | 2014 |
| Swanfield Limited | Hospitality | 1992 |
| Swanlands Consultancy Ltd | Professional & scientific | 2017 |
| SWEETSTORE1212 Limited | Wholesale & retail | 2026 |
| Swift Stunts Ltd | Arts & recreation | 2018 |
| Swifteats Limited | Transport & logistics | 2025 |
| Swinburne Properties Limited | Administrative & support | 2018 |
| Swindon Land Limited | Administrative & support | 2012 |
| Swingdeal Limited | Construction | 2000 |
| Swipesecure Limited | Administrative & support | 2026 |
| SWT Studios Limited | Arts & recreation | 2025 |
| SX Mortgages Limited | Financial services | 2023 |
| SYL Investment Limited | Financial services | 2016 |
| Sylvan Marketing Limited | Professional & scientific | 2003 |
| Symes Investments Limited | Real estate | 2021 |
| Symoqin Ltd | Wholesale & retail | 2024 |
| Synchronized Limited | Information & communication | 2001 |
| Synergy Construct Ltd | Construction | 2019 |
| Synerhub Ltd | Information & communication | 2019 |
| Synervit Limited | Health & social care | 2005 |
| Syno Associates Limited | Professional & scientific | 2023 |
| Syon Court Management Company Limited | Households | 2002 |
| Syranidis Limited | Wholesale & retail | 2025 |
| Sysco Infotech Ltd | Information & communication | 2021 |
| System Building Solutions Ltd | Construction | 2017 |
| Systemic Counselling Ltd | Health & social care | 2026 |
| T & S Commercial Repair Ltd | Wholesale & retail | 2007 |
| T & S Locum Consultancy Ltd | Health & social care | 2025 |
| T Davies Contracts Limited | Construction | 2012 |
| T F Rail Ltd | Construction | 2017 |
| T Force Ltd | Hospitality | 2016 |
| T Logistics Group Limited | Transport & logistics | 2023 |
| T Reed Electrical Services Limited | Energy | 2015 |
| T Tech Developments Ltd | Professional & scientific | 2022 |
| T. Braman Developments and Investments Limited | Real estate | 2010 |
| T.C.S. Janitorial Supplies Limited | Wholesale & retail | 2000 |
| T.J.S. Global Logistics Limited | Transport & logistics | 2007 |
| T.P.Holland & SON Limited | Other services | 1962 |
| T.R. Sterling Limited | Manufacturing | 1999 |
| T.T. Holdings & Investments Limited | Financial services | 2025 |
| Taac Asset Management Limited | Real estate | 2023 |
| Taac Rental Ltd | Real estate | 2023 |
| TAB Consulting Services Limited | Professional & scientific | 2019 |
| Tablespoon Limited | Hospitality | 2008 |
| Tabors Court Freehold Limited | Households | 1998 |
| Tack Electrical Solutions Limited | Construction | 2012 |
| Tack Room Limited | Real estate | 2021 |
| Tacltd Limited | Professional & scientific | 2024 |
| TAG Works Ltd | Manufacturing | 2025 |
| Tailormade Healthcare Ltd | Administrative & support | 2018 |
| Tain Limited | Administrative & support | 2017 |
| Taka 21 Ltd | Hospitality | 2025 |
| Talent 82 Limited | Administrative & support | 2018 |
| Talking Music Limited | Arts & recreation | 2011 |
| Tallack Road Developments Limited | Construction | 2015 |
| TAM Clean Ltd | Administrative & support | 2020 |
| Tamorah Properties Limited | Professional & scientific | 1994 |
| Tamp Trading Ltd | Hospitality | 2016 |
| Tanacchi Limited | Professional & scientific | 2010 |
| Tandoor Limited | Hospitality | 2015 |
| Tangent Management Limited | Information & communication | 2005 |
| Tangie Limited | Real estate | 2023 |
| Tapestry Stone Ltd | Manufacturing | 2018 |
| Taphaz Limited | Hospitality | 2021 |
| Tapp Renewables Ltd | Construction | 2021 |
| Taqdam Spectrum Ltd | Health & social care | 2015 |
| Taran Fashion UK Ltd. | Wholesale & retail | 2022 |
| Targeted Digital Solutions Ltd | Professional & scientific | 2021 |
| Tarj Construction Ltd | Construction | 2022 |
| Taskcove Limited | Administrative & support | 1998 |
| Tatham & Gallagher Limited | Construction | 1999 |
| Tax Care Accounting Services Ltd | Professional & scientific | 2023 |
| Taxi Two Hire Limited | Transport & logistics | 2019 |
| Taxpoint Accountants Limited | Extraterritorial | 2009 |
| Taxpoint Direct (GB) Holdings Ltd | Professional & scientific | 2017 |
| Taxpoint Direct Accountants Limited | Extraterritorial | 2009 |
| Taxpoint Direct Limited | Professional & scientific | 2005 |
| Taxpoint Secretaries Limited | Extraterritorial | 2005 |
| Taxpoint Training Services Limited | Education | 2009 |
| Taxpro Consultancy Ltd | Professional & scientific | 2018 |
| Taxvisers Ltd | Extraterritorial | 2016 |
| Tayler Foods Ltd | Wholesale & retail | 2011 |
| Taylor & Co Property Holdings Ltd | Real estate | 2023 |
| Taylor Hyland Co Ltd | Hospitality | 2023 |
| Taylor Mormont Limited | Financial services | 2019 |
| Taylored HQ Ltd | Other services | 2025 |
| Taylormade Brickwork Limited | Construction | 2020 |
| TB Carpentry & Joinery Ltd | Construction | 2018 |
| TC Lumina Assetco Ltd | Administrative & support | 2025 |
| TC Star Assetco Ltd | Administrative & support | 2025 |
| TCM Group Limited | Hospitality | 2019 |
| TCW Solutions Ltd | Information & communication | 2012 |
| TD Cashflow Solutions Limited | Real estate | 2019 |
| Tddu Holdings Limited | Real estate | 2026 |
| TDS Comms Ltd | Other services | 2015 |
| TDS Style Ltd | Other services | 2016 |
| Team Cooper Paul Limited | Professional & scientific | 2021 |
| Team Shogun Ltd | Education | 2022 |
| Teamsos Education Limited | Information & communication | 2020 |