| Land and Sea Forensics Limited | Administrative & support | 2019 |
| Landman Residential Limited | Real estate | 2022 |
| Landmark Cert Ltd | Other services | 2024 |
| Landmark Rooms Ltd | Real estate | 2022 |
| Landsend Fishery Limited | Agriculture & fishing | 2020 |
| Langdale Property NE Ltd | Construction | 2025 |
| Lansor Limited | Information & communication | 2025 |
| Lape Group Limited | Professional & scientific | 2025 |
| Large Format UK Limited | Manufacturing | 2007 |
| Larov Limited | Real estate | 2024 |
| Last Arrow Limited | Administrative & support | 2025 |
| Last Night Limited | Arts & recreation | 2002 |
| LAT Property Ltd | Real estate | 2017 |
| Latate Limited | Administrative & support | 2001 |
| Late Night Dlvry (Newcastle) Ltd | Transport & logistics | 2025 |
| Late Night Dlvry (Nottingham) Ltd | Transport & logistics | 2025 |
| Latha Medical Services Limited | Health & social care | 2014 |
| Latha Properties Ltd | Real estate | 2019 |
| Lato Holdings Ltd | Financial services | 2016 |
| Latway Limited | Real estate | 2014 |
| LAU Medical Services NE Ltd | Health & social care | 2013 |
| Launch Investments Ltd | Real estate | 2023 |
| Laura Lancaster Limited | Arts & recreation | 2022 |
| Laurel and Leather Limited | Arts & recreation | 2025 |
| Laurel House School Limited | Education | 2024 |
| Lava Bathrooms and Tiles Ltd | Real estate | 2018 |
| Lavasani Holdings Limited | Financial services | 2026 |
| Lavin Management Consultancy Ltd | Professional & scientific | 2021 |
| Lavished by Lucia Ltd | Other services | 2025 |
| Lavitarak Limited | Professional & scientific | 2024 |
| Layan Properties Ltd | Real estate | 2025 |
| Layercom Network Design and Installation Ltd | Information & communication | 2006 |
| Layers Studio Limited | Professional & scientific | 2015 |
| Layla 1 Limited | Hospitality | 2020 |
| Lazbro Limited | Real estate | 2018 |
| Lazy George's Ltd | Hospitality | 2017 |
| Lazy Joe's Ltd | Wholesale & retail | 2021 |
| LB (NE) Limited | Administrative & support | 2022 |
| LB Beauty Distribution Ltd | Other services | 2025 |
| LC Electrical (NE) Limited | Construction | 2018 |
| LC Property NE Limited | Real estate | 2025 |
| LCL Home Life Ltd | Real estate | 2018 |
| LCR Solutions North East Ltd | Construction | 2021 |
| LD Elite Development Ltd | Professional & scientific | 2019 |
| LD Hygienist Services Limited | Health & social care | 2025 |
| LD Property Maintenance Limited | Construction | 2025 |
| LD Showjumping Limited | Arts & recreation | 2023 |
| LDA Group Building Services Limited | Construction | 2022 |
| LDA Group Construction Limited | Construction | 2024 |
| LDA Group Holdings Limited | Financial services | 2022 |
| LDA Group Limited | Construction | 2021 |
| LDH Access Solutions Ltd | Manufacturing | 2026 |
| LDI Tech Software Ltd | Information & communication | 2024 |
| LDW Solutions Limited | Administrative & support | 2024 |
| LE Breve International Limited | Wholesale & retail | 2012 |
| Leadun Ltd | Real estate | 2019 |
| Leadwell Policing Advisory Ltd | Professional & scientific | 2025 |
| Leam Lane Hair Lounge Ltd | Other services | 2023 |
| Leam Lane Takeaway Limited | Hospitality | 2014 |
| Leam TTC Ltd | Professional & scientific | 2023 |
| Leamside Estates Limited | Health & social care | 2012 |
| LEAN2EXCEL Limited | Administrative & support | 2024 |
| Leanne Cook Accounting Limited | Professional & scientific | 2020 |
| Learning Concepts Limited | Education | 2004 |
| Learnmedicine Ltd | Education | 2020 |
| Leazes Park Properties Limited | Real estate | 1987 |
| LED Expert Limited | Wholesale & retail | 2015 |
| LEE Investments Limited | Financial services | 2019 |
| LEE Wylie Boxing Ltd | Arts & recreation | 2024 |
| LEF Investment Properties Limited | Financial services | 2024 |
| Legacystone LLP | | 2025 |
| Legal Intelligence Ltd | Administrative & support | 2024 |
| Legal Translate Ltd | Professional & scientific | 2015 |
| Legends Barbershop (NE) Limited | Other services | 2026 |
| Legh Management Limited | Real estate | 2012 |
| Leisure North East Ltd | Extraterritorial | 2006 |
| Lemax Inspection Ltd | Professional & scientific | 2011 |
| Lemon Printing Company Limited | Manufacturing | 2006 |
| Lemondoc Limited | Health & social care | 2022 |
| Lens Health Technologies Limited | Information & communication | 2024 |
| Leon James Property Ltd | Construction | 2025 |
| Leon Walker Ltd | Information & communication | 2008 |
| Leon's Removals Ltd | Transport & logistics | 2022 |
| Leonard Solutions Ltd | Professional & scientific | 2018 |
| Leopard Juice Artistry Limited | Other services | 2021 |
| LEP 1 Limited | Real estate | 2022 |
| LEP Commercials Ltd | Real estate | 2026 |
| LEP Group NE Limited | Financial services | 2025 |
| Leromart Ltd | Wholesale & retail | 2026 |
| LES Howarth Joinery Limited | Construction | 2025 |
| LES' Deli Limited | Hospitality | 2025 |
| Leslon Ltd | Real estate | 2021 |
| LET Direct Finders Limited | Real estate | 2010 |
| LET Direct NE Limited | Real estate | 2005 |
| Let's Source Ltd | Real estate | 2020 |
| Lethe Ltd | Health & social care | 2019 |
| Lets Party Events North East LLP | | 2022 |
| Letsargo Ltd | Information & communication | 2023 |
| Levana NE Ltd | Other services | 2024 |
| Leven Ridge Developments Limited | Construction | 2014 |