| Jithesh Retail Ltd | Wholesale & retail | 2020 |
| JKL Hair Ltd | Other services | 2026 |
| JL Willow Ltd | Hospitality | 2026 |
| JLT Financial Limited | Professional & scientific | 2017 |
| JM Holdings & Property Management Ltd | Real estate | 2025 |
| JM Repairs and Maintenance Ltd | Construction | 2017 |
| Joanna Toys Ltd | Wholesale & retail | 2018 |
| Joblings of Whitley Bay Limited | Wholesale & retail | 2003 |
| JOE Bird Ltd | Other services | 2020 |
| John Aynsley Holdings Limited | Financial services | 2024 |
| John Brewis and Co., Accountants Limited | Professional & scientific | 2014 |
| John Campey Lettings Ltd | Real estate | 2017 |
| John Donoghue Photographer Limited | Professional & scientific | 2007 |
| John Knapton Consultant Engineers Limited | Professional & scientific | 2016 |
| John Raper Consulting Ltd | Health & social care | 2010 |
| Jonathan James Pathways Limited | Education | 2025 |
| Jones & Co Developments Ltd | Construction | 2025 |
| Jones & Walker Properties Limited | Real estate | 2021 |
| JPG Joinery Services Ltd | Construction | 2016 |
| JPM Inspections Limited | Mining & quarrying | 2014 |
| JPW Consultancy Ltd | Professional & scientific | 2019 |
| JRB Auto Electrics Ltd | Wholesale & retail | 2022 |
| JSP Trading Ltd | Wholesale & retail | 2022 |
| JTD Properties Ltd | Real estate | 2019 |
| Juke Box Sales and Rentals Limited | Real estate | 1960 |
| Junction Spice Ltd | Hospitality | 2023 |
| Juno Lawrence Ltd | Hospitality | 2025 |
| JW Hair Northeast Ltd | Other services | 2024 |
| JW Safety Ltd | Health & social care | 2026 |
| K & S Retail Ltd | Wholesale & retail | 2012 |
| K G Consulting Solutions Limited | Education | 2016 |
| K Hansen Joinery Ltd | Construction | 2018 |
| K. Brock Ltd | Wholesale & retail | 2012 |
| Kaat Cases Limited | Manufacturing | 2001 |
| KAP Supervision Ltd | Construction | 2016 |
| Kareem Investments Ltd | Real estate | 2020 |
| Kareem Property Management Ltd | Real estate | 2020 |
| Katehallidayhair Ltd | Other services | 2025 |
| Katie J Tattoo Ltd | Other services | 2025 |
| KAY M Holdings Limited | Real estate | 2024 |
| KBS Hairdressing Ltd | Other services | 2017 |
| KD Home Investments Limited | Real estate | 2025 |
| Kennair Ltd | Professional & scientific | 2021 |
| KEW Lets Ltd | Real estate | 2022 |
| Kewin Lawson Smith Limited | Construction | 2019 |
| Kewin North Limited | Information & communication | 2014 |
| Keyturn Property Solutions Ltd | Real estate | 2025 |
| KGM Electrical Ltd | Construction | 2025 |
| KH Bespoke Joinery Ltd | Construction | 2022 |
| Khass Leisure Ltd | Hospitality | 2024 |
| KHL Educational Consultants Ltd | Education | 2020 |
| Kidd & Spoor Solicitors Limited | Professional & scientific | 2015 |
| Kingfisher Gardening and Safety Services Limited | Administrative & support | 2016 |
| Kinghorn& SON Ltd | Manufacturing | 2015 |
| Kiosk Waterpark Ltd | Hospitality | 2024 |
| Kitchen by the Coast Ltd | Hospitality | 2025 |
| Kitchen Renovations Ltd | Construction | 2019 |
| KJG Heating Ltd | Construction | 2021 |
| KJM Wind Limited | Professional & scientific | 2022 |
| KL Rotation Ltd | Construction | 2025 |
| Klaze Limited | Extraterritorial | 2023 |
| KLS Online Limited | Wholesale & retail | 2023 |
| Knock on the Door Enterprises Limited | Hospitality | 2015 |
| Kopa Properties Limited | Households | 2024 |
| KPI Law Limited | Professional & scientific | 2021 |
| KPI Search Ltd | Professional & scientific | 2026 |
| KPR Newcastle Ltd | Hospitality | 2023 |
| KPS Building & Maintenance Limited | Construction | 2013 |
| Kristian Young Film Ltd | Information & communication | 2016 |
| KSP Property NE Ltd | Real estate | 2022 |
| Ktlm Ltd | Professional & scientific | 2022 |
| KW Brant Consulting Ltd | Professional & scientific | 2022 |
| L & K Lets Limited | Real estate | 2015 |
| L Godfrey Pipe Technician Ltd | Mining & quarrying | 2021 |
| L L Promotions Ltd | Construction | 2004 |
| L S J Construction Limited | Construction | 2010 |
| L&M Fencing & Decking Ltd | Construction | 2025 |
| L.B. Finch Roof Contracting Ltd | Construction | 2024 |
| LA Casetta Whitley Bay Ltd | Hospitality | 2017 |
| Lackenby & Charlton Ltd | Construction | 2019 |
| Laeviv Ltd | Other services | 2019 |
| Laird Aviation Limited | Transport & logistics | 2022 |
| LAJ Properties (NE) Ltd | Real estate | 2018 |
| Lakes & Dales (Wheatridge) Limited | Extraterritorial | 2019 |
| Last Bastion Property Ltd | Real estate | 2021 |
| Latlow Developments Limited | Real estate | 2016 |
| Laurels Productions Limited | Hospitality | 2024 |
| Lazarus Home for Girls Ltd | Extraterritorial | 2009 |
| LB GAS Ltd | Manufacturing | 2026 |
| LC Piping Services Ltd | Other services | 2025 |
| LC Public House Limited | Hospitality | 2020 |
| Leaders by Design Ltd | Education | 2023 |
| Leaks & Locks Installations Limited | Construction | 2016 |
| Leander and Black Apparel Ltd | Wholesale & retail | 2023 |
| Leander and Black Ltd | Wholesale & retail | 2019 |
| LEE Maddison Roofing Ltd | Construction | 2023 |
| Lenore Care Ltd | Health & social care | 2018 |
| LES Rayner Foxhunters Motor Company Ltd. | Wholesale & retail | 1993 |
| Letsafe NE Ltd | Real estate | 2013 |
| Letterbox Friendly Limited | Wholesale & retail | 2009 |