| Swanley Bakery Ltd | Manufacturing | 2025 |
| Swanstein Group Ltd | Financial services | 2022 |
| Swanstein Property Developments Ltd | Construction | 2022 |
| Swanstein Property Investments Ltd | Real estate | 2022 |
| Swanstein Property Ltd | Real estate | 2022 |
| Swanton Creatives Ltd | Information & communication | 2026 |
| Swaras Stylist Barbers Ltd | Other services | 2019 |
| Swastik PVT Ltd | Information & communication | 2025 |
| Sweet PEA Floristry Limited | Wholesale & retail | 2016 |
| Sweetie PIE London Ltd | Hospitality | 2025 |
| Swift Retouching Ltd | Professional & scientific | 2022 |
| Swishd Ltd | Information & communication | 2015 |
| Switch 2 Talk Ltd | Information & communication | 2020 |
| SWM Lettings Ltd | Real estate | 2025 |
| Sydney Arms Chislehurst Limited | Hospitality | 2025 |
| Syer Advisers Limited | Other services | 2018 |
| Sykes Broadcast Services Limited | Information & communication | 2018 |
| Sykes Media Services Limited | Information & communication | 2019 |
| Sykes Property Services Limited | Real estate | 2018 |
| Symmetry One Ltd | Information & communication | 2005 |
| Symmetry Project Soloutions Ltd | Construction | 2019 |
| Syn-Rg Consulting Limited | Professional & scientific | 2013 |
| Syn-Rg Lettings Limited | Real estate | 2014 |
| Syn-Rg Limited | Professional & scientific | 2013 |
| Synapticon Ltd | Information & communication | 2016 |
| Synatar Ltd | Information & communication | 2026 |
| Synergise Wealth Group Limited | Administrative & support | 2025 |
| SYNERGY20 Limited | Real estate | 2020 |
| SYNERGY2212 Ltd | Professional & scientific | 2016 |
| Synfiny Advisors UK Limited | Professional & scientific | 2022 |
| Synsera Homes Limited | Construction | 2016 |
| Synsera Medical Limited | Health & social care | 2017 |
| Synthesse Ltd | Manufacturing | 2021 |
| Syon Medical Limited | Health & social care | 2025 |
| Syscaf Limited | Construction | 2016 |
| Systematic Marketing Limited | Information & communication | 1990 |
| Systhinkr Ltd | Wholesale & retail | 2026 |
| Szlobogyan Ltd | Construction | 2023 |
| T & C S Limited | Construction | 2005 |
| T & L Vehicle Repairs Ltd | Wholesale & retail | 2023 |
| T & S Electrical Retail Limited | Wholesale & retail | 2009 |
| T & T Painting & Decorating & Services Ltd | Construction | 2019 |
| T & W Property Maintenance Limited | Wholesale & retail | 1999 |
| T & Y Services Ltd | Health & social care | 2006 |
| T Connolly Family Investment Company Limited | Other services | 2020 |
| T Geczy Ltd | Construction | 2009 |
| T H E Sunshine Touch Ltd | Other services | 2019 |
| T James Luxury Stays Ltd | Hospitality | 2026 |
| T James Social Management Ltd | Professional & scientific | 2020 |
| T T Leisure Limited | Arts & recreation | 2018 |
| T&D Property Management Limited | Households | 2020 |
| T&I Auto Services Ltd | Wholesale & retail | 2025 |
| T&I Consultants Ltd | Other services | 2025 |
| T&M Pipelines Limited | Construction | 2004 |
| T&T Network Holdings Limited | Financial services | 2018 |
| T. a. White Estates Ltd | Real estate | 2021 |
| T.A.F.D. Agencies Ltd | Wholesale & retail | 2003 |
| T.W Roofing Solutions Ltd | Construction | 2024 |
| Tabalt Limited | Information & communication | 2025 |
| Tabinacci Ltd | Wholesale & retail | 2023 |
| Tacoa Estates Limited | Real estate | 2010 |
| TAG Trauma Action Group Limited | Professional & scientific | 2019 |
| Tagoe Ltd | Administrative & support | 2025 |
| Taher Paribahan Ltd | Hospitality | 2019 |
| Tahlx Ltd | Information & communication | 2025 |
| TAI CHI Simplicity Limited | Health & social care | 2020 |
| Tajibos Ltd | Manufacturing | 2024 |
| Takshak Limited | Hospitality | 2023 |
| Talia Learning Ltd | Education | 2025 |
| Talk to Femora CIC | Information & communication | 2025 |
| Tamak Cafe Ltd | Hospitality | 2022 |
| Tamb Film & Video Production Ltd | Wholesale & retail | 2026 |
| Tammy Marlar Photography Ltd | Professional & scientific | 2024 |
| Tams Food and Wine Ltd | Wholesale & retail | 2022 |
| Tanah Investment Ltd | Real estate | 2021 |
| Tannahill Properties Limited | Real estate | 2022 |
| Tantolu Limited | Health & social care | 2013 |
| Tape Renovation Limited | Construction | 2025 |
| Tapi Carpets & Floors Limited | Wholesale & retail | 2014 |
| Tara Aghdashloo Studios Limited | Professional & scientific | 2017 |
| Targetcolour Limited | Professional & scientific | 2024 |
| Tarhan Associates Limited | Professional & scientific | 2018 |
| Tarhuna Support Ltd | Health & social care | 2018 |
| Tarnwood Ltd | Information & communication | 2017 |
| Tarragon Bell Limited | Extraterritorial | 2024 |
| Tarven Electrical Contractors Limited | Construction | 2017 |
| Task Seuk Limited | Professional & scientific | 2019 |
| Taste BUD Deli Ltd | Hospitality | 2013 |
| Tattoo Machine Supply Limited | Wholesale & retail | 2009 |
| Taurus Project Solutions Ltd | Construction | 2017 |
| Taurus Property Group Limited | Financial services | 2018 |
| Tax Bridge Solutions Limited | Professional & scientific | 2026 |
| Taxi Marshals Limited | Information & communication | 2018 |
| Taxp Servcies Limited | Professional & scientific | 2025 |
| Taylor Made Components Ltd | Manufacturing | 2024 |
| Tazvi Homes Ltd | Real estate | 2019 |
| Tazvi Limited | Information & communication | 2014 |
| TB Elliott Flooring Limited | Construction | 2011 |
| TB Stays Ltd | Real estate | 2025 |
| TC Law Limited | Professional & scientific | 2014 |