| TLC Building Construction Ltd | Construction | 2026 |
| TLC4YOU Limited | Other services | 2011 |
| TM Building Services Limited | Construction | 2017 |
| TM Chauffeur Services Limited | Transport & logistics | 2022 |
| TM Construction & Sons Limited | Construction | 2026 |
| TM IT Repair Limited | Information & communication | 2024 |
| TM Prestige Motion Ltd | Administrative & support | 2025 |
| Tmautohub Ltd | Wholesale & retail | 2025 |
| TMC Legal Limited | Administrative & support | 2019 |
| TMC Legal Services Limited | Administrative & support | 2006 |
| TMD Equity Limited | Real estate | 2018 |
| TMP Interiors Limited | Construction | 2012 |
| TMS Lifeline Training Limited | Information & communication | 1997 |
| TNQ Properties Ltd | Real estate | 2023 |
| Tnsp Ltd | Information & communication | 2023 |
| Tobias Wapshare Associates Ltd | Professional & scientific | 2025 |
| Todays Spice Ltd | Hospitality | 2023 |
| Tofim Global Ltd | Wholesale & retail | 2023 |
| Tokarski Logistics Ltd | Transport & logistics | 2018 |
| Tokenhouse Properties Ltd | Hospitality | 2026 |
| TOLER8 Limited | Information & communication | 2024 |
| Toltec Advisors Limited | Professional & scientific | 2026 |
| Tomsoft Ltd | Information & communication | 2026 |
| Tonetech Ltd. | Manufacturing | 2007 |
| Tonia George Interiors Limited | Professional & scientific | 2025 |
| Toniea Engineering FX Ltd | Manufacturing | 2012 |
| Tooltec (High Wycombe) Limited | Wholesale & retail | 2010 |
| Tooltec (High Wycombe) Machinery Limited | Wholesale & retail | 2013 |
| Tooltec (HW) Limited | Extraterritorial | 2019 |
| Tooltec HW Saws Ltd | Manufacturing | 2017 |
| Tooth Tech Ltd | Health & social care | 2026 |
| Toothfairy Temps Ltd | Health & social care | 2025 |
| Top Fixing Installing Ltd | Construction | 2021 |
| Top Global Foods Ltd | Wholesale & retail | 2024 |
| Top Notch PA Limited | Administrative & support | 2016 |
| Top Property Group Limited | Real estate | 2018 |
| Top Property Rental Limited | Real estate | 2018 |
| Top Tread Tyre, Exhaust & MOT Centre Ltd | Wholesale & retail | 2024 |
| Top Waste Ltd | Water & waste | 2019 |
| TOP10 Construction Ltd | Construction | 2025 |
| Topbins Ltd | Wholesale & retail | 2016 |
| Topbytes Ltd | Information & communication | 2024 |
| Topchoice Roofing & Building Ltd | Construction | 2024 |
| Topchoiceuk Ltd | Wholesale & retail | 2025 |
| Topmarks Maintenance Limited | Construction | 2019 |
| Tops 2407 Limited | Hospitality | 2024 |
| Tops Pizza High Wycombe Limited | Hospitality | 2022 |
| Toptropics Ltd | Wholesale & retail | 2010 |
| Toria LEE Limited | Wholesale & retail | 2004 |
| Tortize & Hare Limited | Wholesale & retail | 2025 |
| TOT Town Nursery Limited | Education | 2005 |
| Total Cleaning Limited | Administrative & support | 2006 |
| Total Maintenance Experts Ltd | Construction | 2023 |
| Total Panacea Ltd | Manufacturing | 2021 |
| Total Plumbing Supplies Limited | Wholesale & retail | 2001 |
| Total Recycling Services Limited | Water & waste | 2009 |
| Total Services & Solutions Ltd | Administrative & support | 2013 |
| Total Services Construct Ltd | Construction | 2024 |
| Total Tax Accountancy Limited | Professional & scientific | 2017 |
| Total Travel Services Ltd | Other services | 2018 |
| Total Tutoring Limited | Education | 2016 |
| Total Tyre & Support Services Limited | Other services | 1995 |
| Total Tyre Group Holdings Ltd | Wholesale & retail | 2020 |
| Totalsolutions Properties Ltd | Households | 2021 |
| Totteridge & District Community Centre Ltd | Arts & recreation | 2008 |
| Totteridge Properties Ltd | Real estate | 2021 |
| Touchet Hall Road Limited | Real estate | 2025 |
| TOW Solution 24/7 Limited | Wholesale & retail | 2024 |
| Tower Fire Alarms Services Limited | Other services | 2000 |
| Town & Varsity Ltd | Professional & scientific | 2010 |
| Towndrow Limited | Professional & scientific | 2016 |
| Townswitch Property Management Limited | Households | 1987 |
| TP Automated Services Limited | Construction | 2017 |
| TP Bizz Ltd | Wholesale & retail | 2023 |
| TPS Recruitment Ltd | Administrative & support | 2024 |
| Tracey Andrews Talent Management Ltd | Arts & recreation | 2024 |
| Tracey Mann Cake School Ltd | Education | 2021 |
| Track and Trap Limited | Extraterritorial | 2001 |
| Track Stuff Limited | Wholesale & retail | 2011 |
| Trade Discount Supplies Limited | Wholesale & retail | 2025 |
| Trade Power Services Limited | Administrative & support | 2024 |
| Trade Roots Consulting Limited | Professional & scientific | 2023 |
| Tradesmen&Labour Supply Limited | Construction | 2014 |
| Trafalgar Compliance Services Limited | Construction | 2011 |
| Trafo Engineering Ltd | Construction | 2025 |
| Training Unity Limited | Other services | 2019 |
| Tralee Farm Venture Limited | Construction | 2017 |
| Tranquil Minds Supported Housing CIC | Health & social care | 2020 |
| Transgen Limited | Professional & scientific | 2014 |
| Transport Treasury Publishing Ltd | Wholesale & retail | 2019 |
| Trap-It Conservation Ltd | Wholesale & retail | 2016 |
| Trasna NA Life Limited | Construction | 2025 |
| Trav Accountancy Services Limited | Professional & scientific | 2019 |
| Travel Friend Corporation Limited | Information & communication | 1994 |
| Travelarc Limited | Information & communication | 2013 |
| Traveltsar.Com Limited | Administrative & support | 2013 |
| Treans Brit Logistic Ltd | Transport & logistics | 2025 |
| Treasure Lynk Limited | Wholesale & retail | 2025 |
| Treat ALL Tree and Garden Maintenance Ltd | Administrative & support | 2025 |
| Treatz Highwycombe Ltd | Hospitality | 2014 |