| T&R Taverns Ltd | Hospitality | 2026 |
| T&S (Louth) Holdings Limited | Financial services | 2025 |
| T&S (Louth) Ltd | Wholesale & retail | 2006 |
| T.D.Roofing Limited | Construction | 2002 |
| Tabula Rasa Louth Ltd | Hospitality | 2023 |
| Tamilithal Limited | Arts & recreation | 2016 |
| Tathwell Farms (Lincs) Limited | Agriculture & fishing | 1962 |
| Tawny OWL & Twit Twoo Ltd | Real estate | 2014 |
| Taylor's Garden Management Company Limited | Households | 2016 |
| TC Heating Limited | Construction | 2018 |
| TC Property Louth Limited | Real estate | 2018 |
| Tear-Away Leisure Limited | Manufacturing | 2003 |
| Tech 9 Services Ltd | Professional & scientific | 2023 |
| Tech Noir Publishing Limited | Information & communication | 2023 |
| Techian Ltd | Information & communication | 2026 |
| Tenstar Automotive Ltd | Education | 2025 |
| Terry Holmes Consultants Limited | Construction | 2014 |
| TES Property (Lincolnshire) Limited | Real estate | 2022 |
| THE Agency (Lincolnshire) Limited | Wholesale & retail | 2019 |
| THE Armour Group (Fleet) Limited | Wholesale & retail | 2025 |
| THE Armour Group (Management) Limited | Professional & scientific | 2019 |
| THE Armour Group Holdings Limited | Financial services | 2023 |
| THE Armour Group Paymaster Limited | Financial services | 2025 |
| THE Atomic Bubble Ltd | Information & communication | 2025 |
| THE Auction House (Louth) Limited | Hospitality | 2019 |
| THE Big Idea (Lincolnshire) CIC | Administrative & support | 2012 |
| THE Café @ Mimi's Ltd | Hospitality | 2024 |
| THE Consortium Louth Ltd | Manufacturing | 2020 |
| THE Cyprinids Angling Club Limited | Agriculture & fishing | 1988 |
| THE Edge of Town Limited | Wholesale & retail | 2025 |
| THE Fact Network Limited | Information & communication | 2021 |
| THE Furrows Management Company Ltd | Households | 2022 |
| THE Glitter Tree Ltd | Wholesale & retail | 2012 |
| THE Golden Fried Fish Ltd | Hospitality | 2023 |
| THE Green PEA Company Limited | Agriculture & fishing | 2006 |
| THE Greyhound Inn (Louth) Limited | Hospitality | 2011 |
| THE Hive (Saltfleetby) Limited | Health & social care | 2023 |
| THE King's Outreach | Education | 2020 |
| THE Kings Head (Louth) Limited | Hospitality | 2009 |
| THE Life Kitchen Collective Ltd | Manufacturing | 2026 |
| THE Lincolnshire Plum Bread Company Limited | Manufacturing | 2010 |
| THE Little Cleaning Co (Lincolnshire) Limited | Administrative & support | 2020 |
| THE Louth Cake Company Ltd | Wholesale & retail | 2025 |
| THE Market Rasen Maltings Court Management Company Limited | Households | 1988 |
| THE New Build Lincs Limited | Hospitality | 2015 |
| THE Panacea (Louth) Limited | Hospitality | 2019 |
| THE Plant Exchange Ltd | Other services | 2026 |
| THE Play Factory Louth Limited | Arts & recreation | 2012 |
| THE Seawaves Saltfleet Ltd | Hospitality | 2017 |
| THE Spice Trail Limited | Manufacturing | 2000 |
| THE Stables Management Company (Tetney) Limited | Households | 2018 |
| THE Tipsy Inn Ltd | Hospitality | 2015 |
| THE Winchester Rooms Limited | Real estate | 2019 |
| THE Wood Shed Outside Catering Limited | Hospitality | 2025 |
| Themis Armour Systems Limited | Professional & scientific | 1990 |
| Thilakan Ltd | Wholesale & retail | 2026 |
| This Abled Life Ltd | Professional & scientific | 2024 |
| Thompson Fleet Ltd | Wholesale & retail | 2024 |
| Thoresby Road Management Company Limited | Professional & scientific | 2019 |
| Thoresway MX Limited | Arts & recreation | 2021 |
| Thurlby Motors Limited | Wholesale & retail | 2006 |
| Tiffany Electrical & Property Services Ltd | Construction | 2019 |
| TIS Guns Ltd | Wholesale & retail | 2024 |
| Titan Metal Fabrications Limited | Manufacturing | 1991 |
| TJB Group Holdings Ltd | Financial services | 2026 |
| TLC the Learning Curve(Lincs) Ltd | Professional & scientific | 2012 |
| TLS Construction Ltd | Construction | 2026 |
| TNO AFC Ltd | Professional & scientific | 2019 |
| TOM Strawson Ltd | Other services | 2016 |
| Tony Griffiths Construction (Louth) Ltd | Construction | 2009 |
| Tony Konarski Limited | Professional & scientific | 2008 |
| Top of the League Media Ltd | Information & communication | 2023 |
| Toro Y Fabrications Ltd | Professional & scientific | 2020 |
| Toro Y Transport Ltd | Transport & logistics | 2021 |
| Torque Haus Automotive Ltd | Wholesale & retail | 2025 |
| Total Resin Solutions Ltd | Construction | 2026 |
| Toucan Plumbing and Heating Ltd | Construction | 2023 |
| Towerbank Limited | Professional & scientific | 2002 |
| Towncove 2011 Ltd | Real estate | 2011 |
| Trading Posts (Lincs) Ltd | Manufacturing | 2026 |
| Trading TT Ltd | Wholesale & retail | 2026 |
| Trailcraft Ltd | Wholesale & retail | 2025 |
| TRE Belle Sorelle Limited | Real estate | 2021 |
| Treat Station Ltd | Hospitality | 2025 |
| Tristan Libell Limited | Hospitality | 2002 |
| Truffle Trees Direct Limited | Agriculture & fishing | 2023 |
| Turfgrass Growers Association Ltd | Other services | 1994 |
| Turkish Pizza Burger Grill Ltd | Hospitality | 2025 |
| Turners Burners Ltd | Construction | 2021 |
| Twain Agriculture Limited | Agriculture & fishing | 2017 |
| Twin Lakes Fishery Limited | Agriculture & fishing | 2026 |
| Tyme Flyes Ltd | Administrative & support | 2018 |
| Tyson's (Ships Riggers) Limited | Manufacturing | 1982 |
| U.K. Apples and Pears Limited | Professional & scientific | 1987 |
| UK Kurdish Barber Limited | Other services | 2022 |
| UK Rail Maintenance Ltd | Transport & logistics | 2013 |
| UK Steel Structures Ltd | Manufacturing | 2022 |
| Ultimate Carpet and Sofa Care Ltd | Administrative & support | 2021 |
| Uneek Solutions Limited | Professional & scientific | 2020 |
| Unique Kids Wellbeing Services Community Interest Company | Wholesale & retail | 2022 |