| Lion Roofing & Developments Limited | Construction | 2021 |
| Liona Ltd | Wholesale & retail | 2025 |
| Lions Restaurant Limited | Hospitality | 2024 |
| Lions Sports Bar & Grill Ltd | Hospitality | 2024 |
| Lionsgate Catering Ltd | Hospitality | 2024 |
| Liquid Lime Ltd | Information & communication | 2019 |
| Lisa Helmanis Limited | Administrative & support | 2013 |
| Lisa Mcgee Education Limited | Education | 2020 |
| Lisa Star Nails Ltd | Other services | 2025 |
| Lisa Star Property Limited | Real estate | 2016 |
| Lisawood Limited | Health & social care | 2023 |
| Lite FX Limited | Professional & scientific | 2018 |
| Lite Global Services Ltd | Extraterritorial | 2025 |
| Little Ducklings Teesside Limited | Health & social care | 2022 |
| Little Industries Ltd | Professional & scientific | 2025 |
| Littleburn Holdings Ltd | Real estate | 2026 |
| Live IT & GET Active CIC | Education | 2017 |
| Live IT Little Ones Ltd | Administrative & support | 2025 |
| Living the Dream Access Limited | Construction | 2011 |
| Livingab Enterprise Ltd | Administrative & support | 2025 |
| Livio Logistics Ltd | Transport & logistics | 2018 |
| LJ Instruments Limited | Professional & scientific | 2023 |
| LJ Minibus Ltd | Transport & logistics | 2025 |
| LJ Properties NE Ltd | Real estate | 2020 |
| LJG Operational Services Ltd | Construction | 2018 |
| LJH Electrical Services Limited | Construction | 2018 |
| Ljjk Services Ltd | Construction | 2025 |
| Ljlpipefitter Ltd | Professional & scientific | 2026 |
| LJM Direct Ltd | Wholesale & retail | 2020 |
| LJM Rigging Services Ltd | Construction | 2019 |
| LJR Properties (NE) Ltd | Real estate | 2022 |
| LJV Accounting Services Limited | Professional & scientific | 2025 |
| LJW Sales Limited | Wholesale & retail | 2025 |
| LK Inspection Services Ltd | Professional & scientific | 2026 |
| LK Lashes Ltd | Wholesale & retail | 2026 |
| LK Nails Ltd | Other services | 2017 |
| LKL Leisure Ltd | Hospitality | 2023 |
| Lkrigging Ltd | Construction | 2021 |
| LL Surveying Limited | Professional & scientific | 2026 |
| LLB Scaffolding Ltd | Construction | 2026 |
| Llck Construction Limited | Construction | 2023 |
| LLF Turf & Amenity Ltd | Extraterritorial | 2020 |
| LLG Power Distribution Limited | Energy | 2022 |
| LLH M&E Services Limited | Construction | 2025 |
| LLJ Construction Solutions Ltd | Construction | 2019 |
| Lloyd Locksmiths Limited | Wholesale & retail | 2004 |
| Lloyd Locksmiths Masterkeying Limited | Wholesale & retail | 2005 |
| Lloyds PCI Contracts Ltd | Construction | 2019 |
| Lloyds PCI Property Services Ltd | Construction | 2019 |
| LLV Electrical Ltd | Construction | 2023 |
| LM Offshore Ltd | Professional & scientific | 2019 |
| LM Properties North East Ltd | Real estate | 2025 |
| LM Services NE Ltd | Construction | 2023 |
| LM Tours Ltd | Administrative & support | 2025 |
| Lmaj Limited | Agriculture & fishing | 2025 |
| LMD Electrical Ltd | Professional & scientific | 2026 |
| LMG OCS Ltd | Professional & scientific | 2018 |
| Lmoffshoresolutions Ltd | Information & communication | 2024 |
| LMR Financial Services Limited | Financial services | 2016 |
| LMR NP Solutions Ltd | Health & social care | 2019 |
| Loak Properties Ltd | Real estate | 2022 |
| Local and National Minibus Hire Ltd | Transport & logistics | 2013 |
| Local Minibus & Coach Travel Ltd | Transport & logistics | 2019 |
| Lochab Logistics Ltd | Administrative & support | 2022 |
| Lock N Load N.E. Limited | Administrative & support | 2026 |
| Lockhart Heritage Plastering Ltd | Construction | 2025 |
| Lockout Direct Limited | Manufacturing | 2014 |
| Lockout Tagout Safety Limited | Manufacturing | 2009 |
| Locks and Silk Ltd | Wholesale & retail | 2025 |
| Locks LAB Ltd | Other services | 2025 |
| Locrky Limited | Health & social care | 2023 |
| Locus Energy Limited | Water & waste | 2025 |
| Lodesman Ltd | Transport & logistics | 2021 |
| Loewe James Developments Ltd | Construction | 2024 |
| Lofthouse Ventures Ltd | Real estate | 2025 |
| Lofty's Inflatables Limited | Arts & recreation | 2018 |
| Logic Recruitment Agency Limited | Administrative & support | 2024 |
| Logical BSP Ltd | Construction | 2023 |
| Logiclevel Limited | Construction | 1990 |
| Logo Visibility Limited | Information & communication | 2021 |
| Londa Mackay Limited | Health & social care | 2017 |
| London College of Applied Studies Limited | Education | 2024 |
| Long Lifting & Rigging Limited | Construction | 2017 |
| Longbeck Holding Ltd | Real estate | 2020 |
| Longlands Bar Ltd | Hospitality | 2025 |
| Longlands CW Ltd | Administrative & support | 2024 |
| Longlands Electrical Ltd | Construction | 2026 |
| Longlands Food Limited | Hospitality | 2023 |
| Longlands Travel Ltd | Wholesale & retail | 2017 |
| Longstaff Estate's Ltd | Real estate | 2021 |
| Lonsdale Lifting Solutions Ltd | Construction | 2025 |
| Lor's Alternative Emporium Limited | Arts & recreation | 2024 |
| Lora Care and Support Limited | Health & social care | 2013 |
| Lord of the Slings Ltd | Professional & scientific | 2025 |
| Lordstones Developments Limited | Construction | 2001 |
| Loren ST. Klair Ltd | Other services | 2003 |
| Lorne Street Studios Ltd | Information & communication | 2026 |
| Lotus Homes North East Limited | Real estate | 2023 |
| Lotus Spa&Wellness Ltd | Health & social care | 2020 |
| Loughman Plant Operations Ltd | Construction | 2016 |