| LJC Property Holdings Ltd | Construction | 2026 |
| LJC Property Solutions Ltd | Construction | 2025 |
| LJC Scaffolding Ltd | Construction | 2021 |
| Ljfarongey Ltd | Health & social care | 2021 |
| LJL Connect Ltd | Administrative & support | 2026 |
| LJO Commercial Ltd | Real estate | 2025 |
| LJO Residential Ltd | Real estate | 2025 |
| LJP Motors Ltd | Wholesale & retail | 2026 |
| LJR Health Limited | Health & social care | 2025 |
| LKR Building Services Ltd | Construction | 2017 |
| Lloyd Drilling Limited | Construction | 1977 |
| LM Electrical & Maintenance Services Ltd | Construction | 2019 |
| LMC Renewables Ltd | Manufacturing | 2022 |
| LMM Coatings Ltd | Construction | 2024 |
| LMP Associates Ltd | Professional & scientific | 2022 |
| LMS Commercials North East Limited | Wholesale & retail | 2021 |
| Loandrive Limited | Financial services | 2024 |
| Lobstar Leisure Ltd | Hospitality | 2023 |
| Local Community Champions CIC | Information & communication | 2026 |
| Lock Pick Mick Ltd | Administrative & support | 2023 |
| Loco Barbers Ltd | Other services | 2022 |
| Locum Light Ltd | Wholesale & retail | 2022 |
| Locum World Limited | Health & social care | 2016 |
| Locumoses Ltd | Health & social care | 2022 |
| Lollak Buildings Limited | Construction | 2025 |
| London and North Western Railway Company Limited | Transport & logistics | 1993 |
| London Wedding Nannies Ltd | Health & social care | 2026 |
| Lonewolf Technologies Ltd | Information & communication | 2022 |
| Long Storrie Productions Ltd | Information & communication | 2024 |
| Longden Walker and Renney (Solicitors) Limited | Professional & scientific | 2012 |
| Longlegs Builders Ltd | Construction | 2025 |
| Lonsdale Hotels Limited | Hospitality | 2000 |
| Lookeye Limited | Wholesale & retail | 1988 |
| LOR Property Ltd | Real estate | 2025 |
| Lord Fleet Services Ltd | Manufacturing | 2024 |
| Lotus Flower School Ltd | Education | 2023 |
| Louisvilleuk Ltd | Transport & logistics | 2024 |
| Love by Lashes Ltd | Other services | 2020 |
| Love Lily at Herrington Park Limited | Hospitality | 2022 |
| Love Lily Cake Design Limited | Hospitality | 2017 |
| Love Lily Distribution Limited | Hospitality | 2022 |
| Love Paris Ltd | Other services | 2024 |
| Loveevol Jewellery Ltd | Manufacturing | 2026 |
| Lovel Property Holdings (North East) Ltd | Real estate | 2024 |
| Lovely Electrical Limited | Construction | 2022 |
| Lovida Ultra Vitality Ltd | Health & social care | 2023 |
| LOW Town Developments Limited | Construction | 2018 |
| Lowden Holdings Limited | Real estate | 2022 |
| Lowerycleaning Ltd | Administrative & support | 2025 |
| LP Accountants Ltd | Professional & scientific | 2018 |
| LP Entertainment Ltd | Information & communication | 2025 |
| LP Trading & Retail Ltd | Wholesale & retail | 2026 |
| LPA Angels NE Ltd | Professional & scientific | 2024 |
| LS Glazing and Repairs Ltd | Construction | 2026 |
| LS OT Services Ltd | Public administration | 2025 |
| LT Fashion Ltd | Wholesale & retail | 2022 |
| LTH Scaffolding Services Ltd | Construction | 2018 |
| LTM Access Ltd | Construction | 2022 |
| LTP 2000 Limited | Professional & scientific | 1999 |
| Luca CK Ltd | Hospitality | 2024 |
| Luca K Properties Ltd | Real estate | 2025 |
| Luca Murphy Renewables Ltd | Professional & scientific | 2025 |
| Luci's Bar and Bistro Limited | Hospitality | 2025 |
| Lucky Drinks 4 U Ltd | Wholesale & retail | 2007 |
| Lucky Lotus YXL Ltd | Hospitality | 2024 |
| Luigi North East Ltd | Hospitality | 2022 |
| Luigis Alnwick Ltd | Hospitality | 2019 |
| Luke Developments Limited | Construction | 2025 |
| Lumen Pathways Limited | Health & social care | 2025 |
| Lumen Subsea Ltd | Construction | 2025 |
| Luminary Photography CIC | Professional & scientific | 2023 |
| Lumley Barbers Ltd | Other services | 2025 |
| Lunarmundi Limited | Information & communication | 2025 |
| LUX PG Ltd | Real estate | 2025 |
| Luxe Property Sales & Lettings Ltd | Real estate | 2024 |
| Luxe TAN Ltd | Other services | 2023 |
| Luxeia Ltd | Information & communication | 2021 |
| Luxlets (NE) Limited | Households | 2025 |
| Luxulite Limited | Wholesale & retail | 2017 |
| Luxury Hospitality Symposium Ltd | Hospitality | 2025 |
| Luxury Wear UK Ltd | Wholesale & retail | 2025 |
| LW Walshaw Contracting Ltd | Construction | 2025 |
| LWG03 Ltd | Real estate | 2025 |
| Lycum Legis Services Ltd | Professional & scientific | 2014 |
| Lyke Enterprises Ltd | Health & social care | 2014 |
| Lynccup Services Limited | Other services | 2023 |
| Lynne's Linen Limited | Administrative & support | 2025 |
| M & S Bespoke Bathrooms Ltd | Construction | 2024 |
| M & S Bespoke Kitchens Ltd | Construction | 2025 |
| M & S Civils (NE) Ltd | Construction | 2018 |
| M & S Plumbing & Drainage Specialists Ltd | Water & waste | 2024 |
| M and D Properties N.E. Limited | Real estate | 2008 |
| M and G Property Rental Limited | Real estate | 2024 |
| M and L Amusements Ltd | Arts & recreation | 2026 |
| M Anderson HV Solutions Limited | Construction | 2016 |
| M Boutique Ltd | Wholesale & retail | 2024 |
| M Buey Associates LLP | | 2023 |
| M Fabrics and Accessories Ltd | Wholesale & retail | 2020 |
| M Force Logistics Ltd | Transport & logistics | 2025 |
| M G Property North Ltd | Real estate | 2026 |