| LAS Rail Solutions Limited | Construction | 2017 |
| Laser Cutouts Group Limited | Manufacturing | 2015 |
| Laser Gulf ENG Ltd | Administrative & support | 2024 |
| Laserase Newcastle Limited | Other services | 2001 |
| Lasheffect Ltd | Other services | 2024 |
| Lashes by Courtney Ltd | Other services | 2024 |
| LASKER21 Ltd | Information & communication | 2021 |
| Last Minute Productions UK Ltd | Information & communication | 2025 |
| Lastminfly Ltd | Administrative & support | 2026 |
| Lasweeney Ltd | Public administration | 2019 |
| Latam Strategies Ltd | Mining & quarrying | 2011 |
| Latent Services Limited | Education | 2021 |
| Latham Procter Limited | Professional & scientific | 2007 |
| Latif Consultancy Limited | Professional & scientific | 2015 |
| Latif Restaurant Limited | Hospitality | 2014 |
| Lattacharlton Communications Limited | Professional & scientific | 2018 |
| Launchpad Digital Solutions Ltd | Information & communication | 2026 |
| Launchpad Research Limited | Professional & scientific | 2002 |
| Laundry and Linen Hire North East Ltd | Other services | 2025 |
| Laura LEA Boutique Ltd | Wholesale & retail | 2017 |
| Laura Mary Art Limited | Arts & recreation | 2017 |
| Lauran Investments Limited | Real estate | 2000 |
| Laurea Project Services Limited | Public administration | 2014 |
| Laurel North Limited | Professional & scientific | 2025 |
| Laurel Quays Management Company Limited | Households | 2021 |
| Lauren Louisa Ltd | Administrative & support | 2026 |
| Lauren Reece Interiors Limited | Wholesale & retail | 2020 |
| Lauriam Limited | Construction | 2014 |
| Laurion Developments Ltd | Real estate | 2025 |
| Lava Homes Limited | Information & communication | 2015 |
| Lavender Health & Beauty Limited | Other services | 2019 |
| Lavery Building NE Limited | Construction | 2026 |
| Lavery Building Services Limited | Construction | 2021 |
| Lavery Damproofing and Plastering Limited | Construction | 2025 |
| Lavish M Ltd | Other services | 2021 |
| Lavross Property Consulting Ltd | Professional & scientific | 2025 |
| Law Agrieng Ltd | Agriculture & fishing | 2018 |
| Law Technical Services Ltd | Manufacturing | 2025 |
| Lawless Energy Consulting Limited | Professional & scientific | 2014 |
| Lawns Osborne Management Company Limited | Households | 1996 |
| Lawrence Conway Properties Limited | Real estate | 2016 |
| Lawrence Energy Ltd | Professional & scientific | 2023 |
| Lawrenson & Grebby Photography LLP | | 2015 |
| Laws GAS and Plumbing Ltd | Administrative & support | 2018 |
| Lawson & Cowell Ltd | Construction | 1988 |
| Lawson 2020 Ltd | Professional & scientific | 2019 |
| Lawson Construction Ltd | Construction | 2019 |
| Lawson Trading Ltd | Real estate | 2025 |
| Lawsons Timber Limited | Wholesale & retail | 1993 |
| Laxxglobal Limited | Wholesale & retail | 2024 |
| LAYER3 Systems Limited | Information & communication | 1995 |
| Layercake Hospitality Ltd | Hospitality | 2016 |
| Layfield Invest Ltd | Real estate | 2024 |
| Laytons Properties Ltd | Real estate | 2021 |
| LB TCM Consultant Clinic Limited | Health & social care | 2018 |
| Lbbhnewco Ltd | Hospitality | 2026 |
| LBE Property Ventures Ltd | Real estate | 2025 |
| Lbrr Access Services Ltd | Construction | 2026 |
| LBS International Ltd | Real estate | 2023 |
| LC Property Estates Ltd | Real estate | 2024 |
| LCA Developments Limited | Real estate | 2019 |
| LCC Consultants Limited | Professional & scientific | 2016 |
| LCC Locums Ltd | Health & social care | 2022 |
| Lccs Business Consultancy Services (NE) Ltd | Professional & scientific | 2023 |
| LCD Astra Ltd. | Professional & scientific | 2011 |
| LCD Ventures Limited | Professional & scientific | 2019 |
| LCL Limited | Health & social care | 2019 |
| LD Talent Ltd | Arts & recreation | 2020 |
| LDC Construction Solutions Ltd | Construction | 2023 |
| LDC Consulting Limited | Financial services | 2026 |
| LDM Engineering Ltd | Mining & quarrying | 2014 |
| LDR Electrics Ltd | Construction | 2024 |
| LDS Leisure Limited | Arts & recreation | 2014 |
| Lead Candidate Ltd | Administrative & support | 2020 |
| Leadership for Growth Limited | Professional & scientific | 2010 |
| Leadgates Developments Limited | Real estate | 2011 |
| Leadout Engineering Ltd | Professional & scientific | 2022 |
| Leaf & Pine Limited | Hospitality | 2025 |
| Leaf and Paws Ltd | Professional & scientific | 2021 |
| Leaf Clean Limited | Administrative & support | 2020 |
| Leaf Hairdressing Limited | Other services | 2003 |
| Leaf.Fm Ltd. | Information & communication | 2014 |
| League of Learning Maths Ltd | Education | 2022 |
| Leah Nesbitt Ltd | Real estate | 2025 |
| Leaholme Cottage Limited | Real estate | 2012 |
| Lean Cuisine Ltd | Hospitality | 2024 |
| Lean Greens Ltd | Hospitality | 2012 |
| Lean Workshop Group Limited | Other services | 2015 |
| Leanne Smith (NE) Limited | Administrative & support | 2025 |
| Leanology Limited | Administrative & support | 2016 |
| Leap Edge Ltd | Information & communication | 2026 |
| LEAP29 Properties Limited | Real estate | 2023 |
| LEAP29AV Limited | Wholesale & retail | 2020 |
| Learn TPM Limited | Information & communication | 2008 |
| Learning Designs Ltd | Information & communication | 1996 |
| Learning Facility Ltd | Education | 2022 |
| Learning for ALL Ltd | Education | 2021 |
| Learning PIT Limited | Education | 2019 |
| Learnmix Ltd | Wholesale & retail | 2023 |
| Lease a Leaf London Limited | Professional & scientific | 2015 |