| Life Effect Chiropractic (UK) Limited | Administrative & support | 2022 |
| Life Effect Chiropractic Limited | Health & social care | 2017 |
| Life Lettings Ltd | Real estate | 2018 |
| Lifeboat Capital Ltd. | Financial services | 2019 |
| Lifeline Agency Limited | Public administration | 2021 |
| Lifeminded Ltd | Other services | 2024 |
| Lifeslice Ltd | Hospitality | 2025 |
| Lifestyle Sales International Limited | Wholesale & retail | 2026 |
| Lift With Luke Ltd | Health & social care | 2024 |
| Light - Tech Limited | Professional & scientific | 1986 |
| Light Creation Company Limited | Professional & scientific | 2020 |
| Light HQ Ltd | Wholesale & retail | 2014 |
| Light Sky Mortgages Ltd | Financial services | 2020 |
| Lightbulb Financial Services Ltd | Professional & scientific | 2024 |
| Lightbulb Holdings Ltd | Financial services | 2022 |
| Lightbulb Perfusion Ltd | Health & social care | 2025 |
| Lightcraft Energy Solutions Ltd | Wholesale & retail | 2022 |
| Lightcraft Technologies Ltd | Manufacturing | 2010 |
| Lighter Living Limited | Wholesale & retail | 2020 |
| Lightermen Quay Management Limited | Households | 2001 |
| Lighthouse Accountancy Services Ltd | Professional & scientific | 2020 |
| Lighthouse and Anchor Holdings Ltd | Financial services | 2026 |
| Lighthouse and Anchor Limited | Real estate | 2023 |
| Lighthouse Healthcare Ltd | Health & social care | 2022 |
| Lighthouse Horizon Limited | Professional & scientific | 2025 |
| Lighthouse Media (UK) Limited | Wholesale & retail | 2012 |
| Lighthouse Nimbus Ltd | Administrative & support | 2005 |
| Lighthouse Visual Communications Limited | Information & communication | 1984 |
| Lightning Books Tech Ltd | Professional & scientific | 2026 |
| Lightning Electrical Limited | Construction | 2025 |
| Lights & Beats Ltd | Transport & logistics | 2016 |
| Lights OUT Manufacturing Limited | Manufacturing | 2023 |
| Lightship Learning Limited | Manufacturing | 2019 |
| Lignarius Carpentry & Building Ltd | Construction | 2025 |
| LIL Foods Ltd | Hospitality | 2023 |
| LIL Zoomers Ltd | Wholesale & retail | 2025 |
| Lila Automotive Ltd | Wholesale & retail | 2026 |
| Lila Baumont Studio Limited | Professional & scientific | 2024 |
| Lilac Library's Ltd | Wholesale & retail | 2024 |
| Lilac P Care Limited | Health & social care | 2025 |
| Lili Southampton Ltd | Hospitality | 2023 |
| Lillies Fashion Boutique Ltd | Wholesale & retail | 2018 |
| Lillith Consultancy Ltd | Professional & scientific | 2024 |
| Lima Legal Services Limited | Professional & scientific | 2020 |
| Limberline Tyres Limited | Wholesale & retail | 1998 |
| Lime House Consultancy Ltd | Professional & scientific | 2024 |
| Lime Laundry Ltd | Other services | 2020 |
| Limited Edition Cleaning Ltd | Administrative & support | 2025 |
| Limited Edition Trainers Limited | Wholesale & retail | 2025 |
| Limitless Digital by Becky Ltd | Professional & scientific | 2025 |
| Limitless Home Projects Ltd | Manufacturing | 2026 |
| Limitless Logistix Ltd | Transport & logistics | 2023 |
| Limitless Martial Arts Ltd | Arts & recreation | 2017 |
| Limitless Mercy Church | Other services | 2023 |
| Limitless Mercy Ministries International | Other services | 2023 |
| Limitless Talent Solutions Ltd | Administrative & support | 2025 |
| LIN Food Limited | Hospitality | 2026 |
| Linc International Limited | Wholesale & retail | 2017 |
| Linchpin Developments Ltd | Construction | 2025 |
| Lincoln Court Maintenance (Southampton) Limited | Households | 1970 |
| Lindal Court Limited | Households | 2003 |
| Linden Court (Southampton) RTM Company Limited | Real estate | 2013 |
| Linden Hall Owners Assoc. Limited | Households | 1998 |
| Lindendove Limited | Households | 1978 |
| Lindsay Delic Kingston Maths Tutor Ltd | Education | 2026 |
| Lindsay of Liphook Limited | Wholesale & retail | 2010 |
| Lindsey's Limited | Administrative & support | 2023 |
| Lindskoog Limited | Information & communication | 2018 |
| Lindyloo's Limited | Wholesale & retail | 2020 |
| Line - Cars Ltd | Transport & logistics | 2024 |
| Line 5 Ltd. | Professional & scientific | 2020 |
| Linen Hire Services Ltd | Administrative & support | 2023 |
| Liners Investments Limited | Real estate | 1924 |
| Lingate Solutions Ltd | Professional & scientific | 2015 |
| Lingland-Interpreters-Translators Limited | Information & communication | 2004 |
| Lingwood Centre Management Limited | Households | 1965 |
| Lingwood Flats Management (NO. 2) Limited | Households | 1966 |
| Lingwood Flats MANAGEMENT(NO.1)LIMITED | Households | 1966 |
| Link Chauffeurs Limited | Transport & logistics | 2018 |
| Link Instruments Limited | Manufacturing | 1998 |
| Link Placement Ltd | Information & communication | 2024 |
| Linked Installations Limited | Construction | 2025 |
| Linkedup Solutions Ltd | Health & social care | 2013 |
| Linkert Developments Limited | Construction | 2023 |
| Linkert Homes Limited | Construction | 2021 |
| Links Posting Ltd | Information & communication | 2025 |
| Linkspm Ltd | Real estate | 2020 |
| Linkwhiz Limited | Construction | 1999 |
| Linney Engineering Limited | Professional & scientific | 1998 |
| Linskill & Co Ltd | Other services | 2012 |
| Linx FS Limited | Financial services | 2009 |
| Linxs Consulting Limited | Information & communication | 2013 |
| Lion Contracting Limited | Administrative & support | 2025 |
| Lion ER Limited | Hospitality | 2025 |
| Lion Heating Limited | Construction | 2009 |
| Lion Retail Ltd | Wholesale & retail | 2019 |
| Lion Spirit Media Limited | Professional & scientific | 2019 |
| Lionheart Contractors Ltd | Construction | 2022 |
| Lionheart Wealth Management Limited | Financial services | 2022 |
| Lipnar Limited | Wholesale & retail | 2010 |