| THE Milk Company (UK) Limited | Hospitality | 2009 |
| THE Mindful Wellness Hub Ltd | Health & social care | 2022 |
| THE Monkey Business Foundation Limited | Administrative & support | 2012 |
| THE Mossi London Laboratories Limited | Wholesale & retail | 2021 |
| THE Multichannel Expert Ltd | Professional & scientific | 2022 |
| THE National Practitioner Support Service Ltd | Information & communication | 2018 |
| THE National Rheumatoid Arthritis Society | Health & social care | 2010 |
| THE Natural Gardening Company Limited | Administrative & support | 2014 |
| THE New Normal Limited | Information & communication | 2013 |
| THE Norden Farm Centre Trust Limited | Arts & recreation | 1992 |
| THE Oak at Knowl Hill Ltd | Hospitality | 2024 |
| THE Off-Site Spraying Company Ltd | Professional & scientific | 2021 |
| THE Old Bike Barn Limited | Wholesale & retail | 2021 |
| THE Old Forge Emporium Limited | Wholesale & retail | 2025 |
| THE Olive Inns Ltd | Hospitality | 2023 |
| THE Parade Day Nursery Limited | Education | 2005 |
| THE Paul Bevan Cancer Foundation | Health & social care | 1993 |
| THE Perfect Brew UK Ltd | Wholesale & retail | 2024 |
| THE Perfect Process Company Limited | Professional & scientific | 2011 |
| THE Phoenix and Claires Court Sports Club Ltd | Arts & recreation | 1983 |
| THE Process - Rehab, Performance and Health Ltd | Education | 2020 |
| THE Professional Tester Ltd | Information & communication | 2013 |
| THE Professionals Club | Professional & scientific | 1999 |
| THE Property Hub (Berkshire) Ltd | Real estate | 2024 |
| THE Purfleet Ship to Shore Conveyor Company Limited | Professional & scientific | 1992 |
| THE Purpose Room Ltd | Professional & scientific | 2020 |
| THE Rank Group PLC | Professional & scientific | 1995 |
| THE Re-Wrap Association CIC | Other services | 2003 |
| THE Real Estate Club LLP | | 2021 |
| THE Recruitment Consultancy Limited | Administrative & support | 1997 |
| THE Red House Newbury Ltd | Hospitality | 2007 |
| THE Reds Property Company Limited | Real estate | 2018 |
| THE Relationship Coaches Limited | Other services | 2009 |
| THE Relocation Group Limited | | 1988 |
| THE Return to Work Centres Limited | Health & social care | 2010 |
| THE Rollerski Co Limited | Wholesale & retail | 2004 |
| THE Ross (Ross) Company Ltd | Construction | 2019 |
| THE Rubbish Boys Ltd | Transport & logistics | 2022 |
| THE RUG Club Limited | Wholesale & retail | 2025 |
| THE Safe Insurance Agency Limited | Professional & scientific | 1998 |
| THE Sales Leadership Alliance Limited | Extraterritorial | 2010 |
| THE Samurai Fitness Group Limited | Arts & recreation | 2010 |
| THE Scooter Cafe Limited | Wholesale & retail | 2008 |
| THE Scrubs Clinic Ltd | Wholesale & retail | 2025 |
| THE Shaft Polo Mallet Company Limited | Manufacturing | 2012 |
| THE Shire Collective Limited | Administrative & support | 2020 |
| THE Skills and Business Hub Limited | Administrative & support | 2011 |
| THE Smae Institute (1919) Limited | Education | 1992 |
| THE Spirits Guide Limited | Information & communication | 2021 |
| THE Stone Company (Bucks) Limited | Manufacturing | 2012 |
| THE Suntan Shop (Maidenhead) Limited | Wholesale & retail | 2018 |
| THE Sycamores Partnership Limited | Professional & scientific | 2018 |
| THE Thames Valley and Great Western Omnibus Trust | Arts & recreation | 2004 |
| THE Thames Valley Traction Company Limited | Transport & logistics | 2013 |
| THE Travel Brand Group Ltd | Administrative & support | 2016 |
| THE Tree Amigos (Berkshire) Limited | Agriculture & fishing | 2012 |
| THE TUK in Ltd | Hospitality | 2025 |
| THE Wealth Management Partnership LLP | | 2002 |
| THE Weint (Colnbrook) M.C. Limited | Households | 2008 |
| THE Wheel Boyz Ltd | Wholesale & retail | 2025 |
| THE White Rose Capital Group Limited | Financial services | 2025 |
| THE Wholesale Collective Ltd | Wholesale & retail | 2025 |
| THE Window Wear Company (GB) Ltd | Professional & scientific | 2014 |
| THE Wonderland Dream Factory Limited | Information & communication | 2014 |
| THE Workplace Mediation Company Ltd | Professional & scientific | 2024 |
| Theatre House (Farnborough) M.C. Limited | Households | 2008 |
| Thedmp Consultancy Ltd | Construction | 1998 |
| Thegun Ltd | Other services | 2018 |
| Theja Apex Ltd | Wholesale & retail | 2025 |
| Thelevelplayingfield CIC | Information & communication | 2026 |
| Theodore Management Limited | Financial services | 2011 |
| Thermo Products Ltd | Manufacturing | 2001 |
| These Charming MEN Limited | Arts & recreation | 2014 |
| Thetrendfull Ltd | Wholesale & retail | 2024 |
| Thewell Life Ltd. | Wholesale & retail | 2016 |
| Think in Code Limited | Professional & scientific | 2010 |
| Think Research PVT Ltd | Real estate | 2015 |
| Think Tech Consulting Ltd | Information & communication | 2024 |
| Thinking Thumbs Physio Limited | Other services | 2023 |
| Thinkthru Ltd | Professional & scientific | 2020 |
| Third Millennium Software Limited | Transport & logistics | 1997 |
| Third Party Liability Limited | Financial services | 2014 |
| Thirty One Across Ltd | Real estate | 2026 |
| Thirty Twenty Limited | Professional & scientific | 2023 |
| Thistleton Quarries Limited | Professional & scientific | 1985 |
| THL Capital Ltd | Financial services | 2025 |
| Thobandass ESK Ltd | Financial services | 2026 |
| Thomas Alexander Design Ltd | Professional & scientific | 2013 |
| Thomas Alexander Interiors Ltd | Professional & scientific | 2023 |
| Thomas Lawrence & Sons (Bracknell) Limited | Real estate | 1936 |
| Thomson & Co Limited | Administrative & support | 2012 |
| Thorn Flooring Limited | Wholesale & retail | 2003 |
| Thornbird Consultancy Limited | Information & communication | 2000 |
| Thorne Rees Property Management Limited | Real estate | 2004 |
| Thoughtstream Limited | Information & communication | 2013 |
| Thoughttrail Ltd | Information & communication | 2026 |
| Threat Finance Intelligence Solutions Ltd | Administrative & support | 2022 |
| Three Peas Consulting Ltd | Administrative & support | 2020 |
| Three Stags Heads Ltd | Hospitality | 2026 |
| Threefold Music Limited | Arts & recreation | 1969 |