| Toolbox Traveller Limited | Manufacturing | 1997 |
| Toolshed Enterprises Ltd | Information & communication | 2012 |
| Top 2 TOE (York) Limited | Other services | 2015 |
| Top Commercials Limited | Wholesale & retail | 2024 |
| Top CUT Tree Services Limited | Agriculture & fishing | 2021 |
| Top Cuts Yorkshire Barbers Limited | Other services | 2021 |
| Top Lobster Ltd | Administrative & support | 2023 |
| Top Roofing Lancashire Ltd | Construction | 2024 |
| Top WAX York Limited | Wholesale & retail | 2025 |
| Top-Let Limited | Real estate | 2008 |
| Topa Leisure Ltd | Hospitality | 2023 |
| Topline Property Maintenance (York) Ltd | Construction | 2026 |
| Topology Limited | Information & communication | 1990 |
| Topspot Housing Limited | Hospitality | 2004 |
| Toreler SAZ School Ltd | Wholesale & retail | 2020 |
| Torque Law LLP | | 2016 |
| Torretta Rossa Ltd | Real estate | 2016 |
| Tose-Smith LLP | | 2018 |
| Total Bathrooms Yorkshire Limited | Construction | 2026 |
| Total Clean York Ltd | Administrative & support | 2023 |
| Total Dental Limited | Health & social care | 2018 |
| Total Electrical Solutions UK Limited | Wholesale & retail | 2004 |
| Total Lettings (York) Ltd | Real estate | 2021 |
| Total Plumbing and Heating (York) Ltd | Construction | 2019 |
| Total Protection Security Group Ltd | Administrative & support | 2025 |
| Total Sell Ltd | Wholesale & retail | 2022 |
| Total Sports Limited | Arts & recreation | 2007 |
| Total System Services Holding Europe LP | | 2006 |
| Total Vehicle Solutions (Ryedale) Limited | Wholesale & retail | 2026 |
| Toto's (York) Limited | Hospitality | 2003 |
| Tourism UK Limited | Administrative & support | 2003 |
| Toursfortips Ltd | Administrative & support | 2013 |
| Towanda Earth Ltd | Wholesale & retail | 2023 |
| Towcester Grange (Apartments) Residents Management Company Limited | Households | 2024 |
| Tower Construction Management Limited | Professional & scientific | 2014 |
| Tower Corporation Limited | Real estate | 1996 |
| Tower Electrics Limited | Construction | 2017 |
| Tower Estates (York) Limited | Real estate | 1951 |
| Tower Law Limited | Professional & scientific | 2013 |
| Tower Metal Productions Ltd | Information & communication | 2020 |
| Towergate Locksmiths Limited | Manufacturing | 2019 |
| Towler Limited | Wholesale & retail | 2005 |
| Towler's Chemist Limited | Wholesale & retail | 2003 |
| Towlers (Properties) Limited | Real estate | 2005 |
| Towlers (Thirsk) Limited | Real estate | 2005 |
| Town & Country Signs (Yorkshire) Limited | Administrative & support | 2015 |
| Townedge (Holdings) Limited | Extraterritorial | 1988 |
| Townedge Estates Limited | Extraterritorial | 1989 |
| Townend Management Services Limited | Professional & scientific | 2023 |
| Townend Way (Helperby) Management Company Limited | Households | 2024 |
| Townscape Architectural Design LLP | | 2021 |
| Townsend Estates LLP | | 2015 |
| Townsend Family Investments LLP | | 2013 |
| Townsend Investments Limited | Real estate | 2010 |
| Townsley Leisure Parks Limited | Hospitality | 2018 |
| Towse Brothers Limited | Agriculture & fishing | 1970 |
| Towse Contracts Ltd | Agriculture & fishing | 2021 |
| Towthorpe Ltd | Manufacturing | 2025 |
| Towthorpe Property Ltd | Real estate | 2026 |
| Towthorpe Trading Ltd | Wholesale & retail | 2026 |
| TP Plumbing Ltd | Professional & scientific | 2007 |
| TP Site Management Services Ltd | Professional & scientific | 2026 |
| TPS York Ltd | Administrative & support | 2026 |
| TQ1 Properties Ltd | Real estate | 2025 |
| Tracey's Red HAT HSR Limited | Administrative & support | 2009 |
| Track Auto Electrics Ltd | Wholesale & retail | 2017 |
| Trackingzone Limited | Extraterritorial | 1998 |
| Tracks and Trucks Limited | Extraterritorial | 2010 |
| Tractilian Ltd | Extraterritorial | 2017 |
| Tractionex Ltd | Information & communication | 2025 |
| Trade 8 Ltd | Hospitality | 2021 |
| Trade Floor Store Ltd | Construction | 2022 |
| Trade-Commerce (York) Ltd | Professional & scientific | 2019 |
| Trademark Finishes Ltd | Construction | 2026 |
| Trademarkinformation.Co.Uk Limited | Professional & scientific | 2007 |
| Tradgard Ltd | Wholesale & retail | 2026 |
| Trading and Risk Education Company (Europe) Limited | Administrative & support | 2023 |
| Trading Specialists Limited | Professional & scientific | 1993 |
| Tradingcardsukcom Ltd | Wholesale & retail | 2022 |
| Traditional Cuts Limited | Other services | 2025 |
| Tradvey Service Ltd | Professional & scientific | 2025 |
| Trafalgar Court (York) Management Company Limited | Households | 2012 |
| Trafalgar Metropolitan Homes Limited | Professional & scientific | 1988 |
| Traffic Engineering Support Services Limited | Professional & scientific | 1995 |
| Trafford Investment Properties Limited | Real estate | 2001 |
| Trafford Investments Limited | Financial services | 1987 |
| Trafford Mortgages Limited | Extraterritorial | 2015 |
| Trah Holdings Ltd | Real estate | 2021 |
| Trailblazer Camps Limited | Health & social care | 2023 |
| TRAIN2 Ltd | Education | 2023 |
| TRANS4MITY Ltd | Hospitality | 2019 |
| Transall Solutions Ltd | Other services | 2013 |
| Transform Facilities Ltd | Administrative & support | 2024 |
| Transform Trainers and Consultancy CIC | Education | 2021 |
| Transform Yorkshire Ltd | Professional & scientific | 2024 |
| Transformational Change Limited | Professional & scientific | 2022 |
| Transit Motorcycles Ltd | Wholesale & retail | 2019 |
| Transit Workshop Limited | Wholesale & retail | 2023 |
| Transition HR Limited | Professional & scientific | 2015 |
| Translatech Limited | Professional & scientific | 1995 |