| Lechlade Roofing Limited | Construction | 2012 |
| LED Recovery Ltd | Transport & logistics | 2026 |
| Ledgerfix Consulting Ltd | Professional & scientific | 2025 |
| LEE Circle Ltd | Real estate | 2019 |
| LEE Paines Ltd | Arts & recreation | 2017 |
| LEE Slender (Property Maintenance) Ltd | Construction | 2014 |
| Leeda Management Limited | Professional & scientific | 2007 |
| Leeds Ice Hockey Ltd | Arts & recreation | 2021 |
| Leenith Properties UK Limited | Real estate | 2024 |
| Leenticing Global Limited | Administrative & support | 2025 |
| Leeokley Company Ltd | Health & social care | 2019 |
| Leftwich Ltd | Professional & scientific | 2026 |
| Legacy Fundraising Ltd | Professional & scientific | 2014 |
| Legacy Incorporated Ltd | Information & communication | 2019 |
| Legacy Lighting UK Ltd | Wholesale & retail | 2023 |
| Legacy’S Construction Ltd | Manufacturing | 2024 |
| Legal Medicine Ltd | Health & social care | 2016 |
| Leighton Commercial Limited | Real estate | 2011 |
| Leisure House Owners Equity Limited | Real estate | 1991 |
| Lekeaza BD Ltd | Wholesale & retail | 2021 |
| Leland Fire and Security Limited | Administrative & support | 2017 |
| Leland Group Ltd | Financial services | 2025 |
| Lemalt Ltd | Transport & logistics | 2022 |
| Leme Ltd | Professional & scientific | 2018 |
| Lena Aviation Limited | Manufacturing | 2026 |
| Lendel Paving Limited | Construction | 2001 |
| Lensart Limited | Manufacturing | 2020 |
| LEO and SON Limited | Construction | 2017 |
| LEO Care Services Limited | Health & social care | 2016 |
| LEO Utilities Ltd | Transport & logistics | 2022 |
| Leonam Transports Ltd | Transport & logistics | 2025 |
| Leppard Distribution Systems LLP | | 2002 |
| LES Smith Haulage (Swindon) | | 1992 |
| LES Smith Haulage Limited | Transport & logistics | 2009 |
| Less Stress Relocations Ltd | Transport & logistics | 2013 |
| Less Stress Removals Ltd | Transport & logistics | 2015 |
| Lessons Learned Ltd | Professional & scientific | 2000 |
| Lesvos Tavern Ltd | Hospitality | 2025 |
| Leszan Travel (Wilts.) Limited | Other services | 2002 |
| Let's Create Art Club Ltd | Other services | 2023 |
| Let's Drive Limited | Education | 2024 |
| Let's Improve Ltd | Information & communication | 2018 |
| Let's Play on Limited | Professional & scientific | 2025 |
| Letnmanage (SW) Ltd. | Households | 2016 |
| Levan Group Limited | Wholesale & retail | 2026 |
| Level UP Construction Services Ltd | Construction | 2022 |
| Level UP Invest L&M Ltd | Real estate | 2025 |
| Level UP Swindon Ltd | Education | 2026 |
| Levels Entertainment Ltd | Hospitality | 2025 |
| Leverage Learning Ltd | Professional & scientific | 2023 |
| Leverton Gate Residents Limited | Households | 1973 |
| Lewdia Limited | Health & social care | 2025 |
| Lewington Wealth Holdings Ltd | Financial services | 2021 |
| Lewinsamuelphotography Ltd | Professional & scientific | 2019 |
| LEWIS54 Catering Ltd | Hospitality | 2018 |
| Lewko Limited | Manufacturing | 2022 |
| LEX Sonos Ltd | Professional & scientific | 2021 |
| Lexxic Limited | Health & social care | 2007 |
| LF LAB Consulting Ltd | Professional & scientific | 2018 |
| LF Starch Process & Consulting Ltd | Professional & scientific | 2026 |
| LFT Property Solutions Ltd | Real estate | 2025 |
| LH Vehicle Damage Repairs Ltd | Wholesale & retail | 2021 |
| LHA Accountancy Services Ltd. | Professional & scientific | 2013 |
| LHD Logistic Ltd | Transport & logistics | 2021 |
| LHE Procurement Ltd | Professional & scientific | 2018 |
| Lhfbc Limited | Real estate | 2023 |
| LHG (Gardens and Trees) Ltd | Other services | 2020 |
| Lhrb Limited | Wholesale & retail | 2016 |
| LHS Transport Ltd | Transport & logistics | 2024 |
| Liamg Healthcare Limited | Health & social care | 2018 |
| Libbysworldofwizardry Limited | Wholesale & retail | 2023 |
| Liberate Law Limited | Professional & scientific | 2024 |
| Libertech Ltd | Extraterritorial | 2025 |
| Liberti Advisors Limited | Financial services | 2026 |
| Liberti FX Limited | Financial services | 2026 |
| Liberti Limited | Professional & scientific | 2014 |
| Liberty and Light Ltd | Wholesale & retail | 2021 |
| Liberty Automobile Limited | Construction | 2015 |
| Libra Construction Ltd | Construction | 2024 |
| Librabit Ltd | Information & communication | 2025 |
| Liden Community Centre Bar Limited | Hospitality | 1990 |
| Liden Pizza & Kebab Ltd | Hospitality | 2022 |
| Life Anchor Limited | Health & social care | 2016 |
| Life Coach UNI Ltd | Administrative & support | 2020 |
| Lifebridge Care Ltd | Health & social care | 2025 |
| Lifecycles IT Consultancy Limited | Information & communication | 2016 |
| Lifeplace Ltd | Health & social care | 2025 |
| Lifestyle Design & Build Limited | | 2008 |
| Light House Security Limited | Other services | 2017 |
| Light View Ltd | Professional & scientific | 2020 |
| Light-Touch HR & Coaching Ltd | Real estate | 2026 |
| Light-Up Media Limited | Professional & scientific | 2019 |
| Lighthouse Partnership Ltd | Health & social care | 2022 |
| Lighting BUG (Swindon) Limited | Wholesale & retail | 1999 |
| Lighting BUG Limited | Extraterritorial | 2016 |
| Lightning Flash Transport Ltd | Transport & logistics | 2020 |
| Lightspan Consulting Limited | Information & communication | 2010 |
| Lignum Properties Limited | Real estate | 2023 |
| Lijack Consultancy Limited | Information & communication | 2011 |
| Likeskin Limited | Wholesale & retail | 2020 |