| LDP Carpentry & Joinery Ltd | Construction | 2020 |
| LDP Communications Ltd | Information & communication | 2013 |
| Leaders.Inc Limited | Professional & scientific | 2013 |
| Leading Constructions Line Ltd | Construction | 2023 |
| Learnforge Limited | Education | 2026 |
| Learnsixsigma.Co.Uk Ltd. | Professional & scientific | 2014 |
| Lebo Associates Ltd | Professional & scientific | 2020 |
| Ledscape Ltd | Wholesale & retail | 2021 |
| LEE Marshall Heating Limited | Construction | 2025 |
| LEE Oliver Illustrator & Concept Artist Limited | Arts & recreation | 2019 |
| Leeds City Hotels Limited | Hospitality | 2024 |
| Legacy Energy Limited | Construction | 2024 |
| Leighton Classics Ltd | Wholesale & retail | 2007 |
| Leighton Grill House Limited | Hospitality | 2023 |
| Leighton Soft Play Ltd | Administrative & support | 2018 |
| Leinster GAS Limited | Manufacturing | 2012 |
| Lemon Rentals Ltd | Wholesale & retail | 2026 |
| Lemon Rocket Cleaning Services Ltd | Administrative & support | 2026 |
| Lenscrafted Limited | Professional & scientific | 2025 |
| Lenzie Consulting Ltd | Professional & scientific | 2012 |
| Lester Eggs Limited | Wholesale & retail | 2010 |
| LET Direct Limited | Extraterritorial | 2000 |
| LET Electrical Services Limited | Construction | 2026 |
| LET ME Check Ltd | Households | 2020 |
| Letchworth Balti Cuisine Limited | Hospitality | 2025 |
| Letous Ltd | Information & communication | 2018 |
| Leveloff Construction Limited | Construction | 2019 |
| Leveloff Foods Limited | Wholesale & retail | 2013 |
| Leveloff Limited | Construction | 2008 |
| Leviathan Industries Limited | Information & communication | 2015 |
| Lexmoto & Pulse Motorcycles Limited | Wholesale & retail | 2014 |
| LH Building Services Limited | Construction | 2011 |
| Li's Takeaway Ltd | Hospitality | 2014 |
| Liberty Educare Limited | Education | 2019 |
| Lidd Ltd | Transport & logistics | 2019 |
| Lifemusicapp Ltd | Information & communication | 2026 |
| Light in Town Limited | Hospitality | 2023 |
| Lightfoot Construction Services Limited | Construction | 2013 |
| LIL MK Limited | Hospitality | 2026 |
| Lili Interior Limited | Professional & scientific | 2022 |
| Lilly's Kitchen Ltd | Hospitality | 2020 |
| Lilwin Care Solutions Limited | Health & social care | 2022 |
| Lily International Limited | Wholesale & retail | 2017 |
| Limelight Spring Limited | Wholesale & retail | 2026 |
| Limited Capacity Ltd | Hospitality | 2025 |
| Lindan Trans Ltd | Transport & logistics | 2018 |
| Lindees Limited | Education | 2002 |
| Lindo Consulting Ltd | Financial services | 2025 |
| Lingham Limited | Hospitality | 2025 |
| Lingolatte Ltd | Information & communication | 2024 |
| Linked Access Hire Limited | Administrative & support | 2018 |
| Links Directcare Ltd | Hospitality | 2021 |
| Linmere Dog Club Ltd | Wholesale & retail | 2023 |
| Lion Corp Ltd | Construction | 2021 |
| Lion Electrical Installations Limited | Construction | 2025 |
| Liona Recruitment Ltd | Administrative & support | 2025 |
| Lions Loom Ltd | Wholesale & retail | 2025 |
| Lionsgate Fresh Eggs Limited | Agriculture & fishing | 2018 |
| Lirasil Limited | Transport & logistics | 2018 |
| Lisa Roberts Catering Limited | Hospitality | 2014 |
| Litratodelala Photography Ltd | Professional & scientific | 2022 |
| Little Lahore Dunstable Ltd | Hospitality | 2025 |
| Little Lightning Collective Ltd | Professional & scientific | 2021 |
| Little Stitch Limited | Wholesale & retail | 2023 |
| Live From Ltd | Information & communication | 2025 |
| Live Laugh Luton Ltd | Real estate | 2026 |
| Live Telecom Limited | Information & communication | 2021 |
| Livewire Connect Limited | Information & communication | 2010 |
| Liviu Calu Limited | Transport & logistics | 2016 |
| LIZ Rogers Art Limited | Education | 2025 |
| LJD Properties Limited | Administrative & support | 2009 |
| LJE Real Estate Ltd | Real estate | 2025 |
| LJF Electrical Limited | Construction | 2022 |
| LJM GBS Limited | Wholesale & retail | 2023 |
| LJS Fabrications Limited | Manufacturing | 2016 |
| LK Spicecorner Ltd | Hospitality | 2026 |
| Lk&M Ltd | Construction | 2020 |
| LKS Properties and Consultancy Ltd | Real estate | 2025 |
| Lku&Son Ltd | Construction | 2023 |
| Llai Investments Ltd | Financial services | 2019 |
| Lloyds Care Solutions Limited | Health & social care | 2022 |
| LMD Trans Ltd | Transport & logistics | 2025 |
| LMP Shuttering and Joinery Construction Limited | Construction | 2017 |
| Loaf Dunstable Ltd | Real estate | 2025 |
| Local Agent Network Limited | Real estate | 2011 |
| Lodge Construction Limited | Construction | 2026 |
| Lodge Group Care and Support Ltd | Administrative & support | 2026 |
| Loeber Trading Ltd | Wholesale & retail | 2021 |
| Logie Baird RTM Company Limited | Households | 2025 |
| Logistic AG Trans Limited | Transport & logistics | 2013 |
| Logistics a+ Ltd | Transport & logistics | 2022 |
| Logistik Transtania Ltd | Transport & logistics | 2013 |
| Logizu Ltd | Wholesale & retail | 2021 |
| Logwood Computing Limited | Information & communication | 1991 |
| Loire Music Limited | Education | 2015 |
| Lollipop Social Studio (LSS) Ltd | Information & communication | 2026 |
| Lolulinks Ltd | Transport & logistics | 2024 |
| London Aspire Real Estate Limited | Manufacturing | 2025 |
| London Blue Limited | Hospitality | 2022 |
| London BS Ltd | Construction | 2019 |