| LCL Engineering Solutions Limited | Manufacturing | 2012 |
| LCS Catering Limited | Hospitality | 2022 |
| LCS Project Management Ltd | Construction | 2016 |
| LDF Services(Ne) Limited | Wholesale & retail | 2020 |
| LDK Property NE Ltd | Real estate | 2026 |
| LE Chappers Media Limited | Information & communication | 2025 |
| LEA Developments (NE) Limited | Real estate | 2022 |
| Leaceh Limited | Wholesale & retail | 2025 |
| Leadbelter Limited | Extraterritorial | 2019 |
| Leading Edge Care Services Ltd | Health & social care | 2013 |
| Leading Edge Concepts Limited | Wholesale & retail | 1996 |
| Leads on Demand Ltd | Administrative & support | 2017 |
| Lealands Consultants Limited | Information & communication | 2022 |
| Leamside Nurseries Limited | Agriculture & fishing | 2022 |
| Lean Development & Improvement Ltd | Professional & scientific | 2015 |
| Leanman Limited | Professional & scientific | 2006 |
| Learnique Learning Ltd | Education | 2025 |
| Leazes Holdings Limited | Administrative & support | 2016 |
| Leazes Ltd | Hospitality | 2011 |
| Leconcepts.Com Ltd | Information & communication | 2024 |
| LEE Stockdale (Electricals) Limited | Construction | 2007 |
| LEE Wilson Logistics Ltd | Transport & logistics | 2025 |
| Lee's Coaches Limited | Administrative & support | 2003 |
| Lee’S Auto Repairs Ltd | Wholesale & retail | 2022 |
| Left Handed and Proud Ltd | Wholesale & retail | 2015 |
| Legacy Company Management Ltd | Wholesale & retail | 2025 |
| Legacy Test Solutions Ltd | Professional & scientific | 2024 |
| Legalloom Limited | Health & social care | 2025 |
| Leicestershire Coins Ltd | Wholesale & retail | 2025 |
| Leisure Caravans Limited | Wholesale & retail | 2008 |
| Leisure Training and Consultancy (North East) Ltd | Education | 2013 |
| Lelaine Properties Ltd | Real estate | 2021 |
| Lemon Management Ltd | Wholesale & retail | 2017 |
| Lemon Property Investment Limited | Real estate | 2017 |
| Lemu Ltd | Wholesale & retail | 2026 |
| Lennys Taxis Limited | Transport & logistics | 2024 |
| Lenore Care Properties Ltd | Real estate | 2019 |
| Leon Bennett International Ltd | Professional & scientific | 2022 |
| Leon Bennett Ltd | Other services | 2020 |
| Leonard Builders North East Limited | Construction | 2025 |
| Lesley Sutheran Holdings Ltd | Real estate | 2022 |
| Lets Pro Digital Ltd | Professional & scientific | 2023 |
| Lever Development Ltd | Administrative & support | 2021 |
| Lever Law Limited | Professional & scientific | 2018 |
| Levia Properties Limited | Real estate | 2019 |
| Levy Construction Ltd | Construction | 2021 |
| Levy Property Holdings Ltd | Real estate | 2022 |
| Lewisburn Limited | Extraterritorial | 2012 |
| LFR Properties Ltd | Real estate | 2023 |
| Liberty Drinks Limited | Wholesale & retail | 2009 |
| Liddon Services Limited | Information & communication | 2002 |
| Life Fit Nutrition Ltd | Wholesale & retail | 2023 |
| Life Smile Homes Ltd | Wholesale & retail | 2025 |
| Lifeline Fire Prevention Ltd | Wholesale & retail | 2012 |
| Lift Performance Academy Ltd | Administrative & support | 2024 |
| Light in the LAB LLP | | 2015 |
| Light Pubs Company Limited | Hospitality | 2026 |
| Lighthouse Employment Ltd | Health & social care | 2007 |
| Lightopia Community Interest Company | Health & social care | 2018 |
| Lightuniversalcleaning Ltd | Administrative & support | 2020 |
| Lignum Construction North East Limited | Construction | 2019 |
| Likeitmedia Ltd | Professional & scientific | 2019 |
| Likuido Limited | Manufacturing | 2026 |
| Lily ANN Limited | Hospitality | 2024 |
| Limec Logistics Ltd | Transport & logistics | 2015 |
| Lindora Lane Ltd | Real estate | 2025 |
| Lingdale Associates Limited | Real estate | 2004 |
| Lion Mouth Community Interest Company | Health & social care | 2012 |
| Lion-Rock Innovation Ltd | Wholesale & retail | 2025 |
| Lions Global Trade Ltd | Wholesale & retail | 2025 |
| Lisa Burt Coaching Ltd | Administrative & support | 2025 |
| Lisimu Ltd | Wholesale & retail | 2026 |
| Little Ballers NE Limited | Arts & recreation | 2019 |
| Little Big Stack Theater Company Ltd | Arts & recreation | 2023 |
| Little Cat Lettings Limited | Real estate | 2026 |
| Little Green Property Ltd | Real estate | 2026 |
| Little Ladybirds Limited | Other services | 2004 |
| Little Newsham Forge Limited | Manufacturing | 2001 |
| Little Sicily Durham 2 Limited | Hospitality | 2025 |
| Little Stars Nursery (ST Bedes) Ltd | Health & social care | 2018 |
| Littletown Cricket Club Members CIC | Arts & recreation | 2019 |
| Live Free Consultancy Ltd | Professional & scientific | 2024 |
| Live Free Housing CIC | Hospitality | 2024 |
| Live on Purpose Limited | Professional & scientific | 2023 |
| Live Sound and Light Production Services Ltd | Professional & scientific | 2018 |
| Livewires Children's Ministry CIC | Education | 2018 |
| Living Lets Ltd | Real estate | 2015 |
| Livn Limited | Hospitality | 2025 |
| LJR Retrofit and Surveying Ltd. | Construction | 2024 |
| LK Home Ltd. | Real estate | 2017 |
| LK Properties & Lettings Ltd | Real estate | 2026 |
| LKL Construction Ltd | Construction | 2026 |
| LM (NE) Limited | Financial services | 2022 |
| LM Brickworks (NE) Ltd | Construction | 2021 |
| LM Consultancy Services Ltd | Professional & scientific | 2007 |
| LME Contracting Limited | Agriculture & fishing | 2020 |
| LMR Tech Ltd | Manufacturing | 2024 |
| LMS Retail Ltd | Wholesale & retail | 2025 |
| Local Safaris Ltd | Administrative & support | 2025 |
| Located Homes Ltd | Real estate | 2023 |