| Life Changing Product Company Limited | Manufacturing | 2024 |
| Life IS an APE Ltd | Hospitality | 2023 |
| Life Support Training and Safety Ltd | Professional & scientific | 2018 |
| Lifeline Bible Church International | Other services | 2023 |
| Lifepoint Church | Other services | 2004 |
| Lifepoint Ltd | Professional & scientific | 2004 |
| Lighthouse Electrical Services Direct Limited | Manufacturing | 2006 |
| Lighthouse Lineage Limited | Professional & scientific | 2025 |
| Lighthouse Properties South Wales Limited | Real estate | 2019 |
| Lighthouse Theatre Ltd | Arts & recreation | 2011 |
| Lily Ryan Hair Ltd | Other services | 2025 |
| Lily's Nails & Beauty Swansea Ltd | Other services | 2024 |
| Lime Bear Ltd | Real estate | 2025 |
| Lime Grove Engineering Limited | Professional & scientific | 2002 |
| Lime Indian Takeaway Ltd | Hospitality | 2021 |
| Limedine Ltd | Hospitality | 2021 |
| Limelight Building Co Limited | Construction | 2019 |
| Limeslade Management COMPANY(2011) Ltd | Hospitality | 2011 |
| Limitless Ecommerce & Vending Limited | Wholesale & retail | 2022 |
| Limitless Energy Ltd | Construction | 2016 |
| Limitlesspumpedup Ltd | Arts & recreation | 2025 |
| Linc-Weld Holdings Limited | Financial services | 2017 |
| Linc-Weld Industrial Supplies Limited | Wholesale & retail | 2003 |
| Lindsay Sian Fitness Limited | Other services | 2019 |
| LINK2CREDIT Ltd | Professional & scientific | 2022 |
| Links Court Management Limited | Hospitality | 1972 |
| Linkword Language Limited | Information & communication | 2025 |
| Lions Maintenance Ltd | Construction | 2025 |
| Lions Property Management Limited | Real estate | 2022 |
| Lions Rugby Limited | Information & communication | 1999 |
| Lionsgate Security and Events Limited | Administrative & support | 2012 |
| Liquid Investments Limited | Financial services | 2005 |
| Liqun Swansea Limited | Wholesale & retail | 2017 |
| Lisa Curzon Ltd | Other services | 2020 |
| Lisa Taylor Design Ltd | Wholesale & retail | 2013 |
| Lisensing Services Ltd | Professional & scientific | 2018 |
| Litchfield Home Ltd | Wholesale & retail | 2022 |
| Litchfield Lettings Limited | Real estate | 2025 |
| Litchfield Property Maintenance Limited | Construction | 2025 |
| Litelok Ltd | Professional & scientific | 2017 |
| Lithostrome Geological Services Ltd | Professional & scientific | 2023 |
| Little Bay Limited | Administrative & support | 2019 |
| Little Bird Consultancy Ltd | Professional & scientific | 2024 |
| Little Broughton Property Ltd | Construction | 2022 |
| Little Buddha Ltd | Hospitality | 2026 |
| Little Dragon Designs Ltd | Wholesale & retail | 2024 |
| Little Dreamers Swansea Limited | Education | 2025 |
| Little Fairy Tales Ltd | Wholesale & retail | 2011 |
| Little Grey Dog Ltd | Other services | 2015 |
| Little House Consultancy Limited | Information & communication | 2015 |
| Little Leaf Property Staging Ltd | Administrative & support | 2026 |
| Little Nippers Day Nursery Limited | Health & social care | 2015 |
| Little TOR Properties Limited | Real estate | 2025 |
| Little Valley Bakery Ltd | Manufacturing | 2019 |
| Little Welsh Valley Meats Ltd | Wholesale & retail | 2022 |
| Littlesteps Child Care Centre Limited | Health & social care | 2006 |
| Lium Creatives Ltd | Information & communication | 2023 |
| LIV & Primrose Ltd | Wholesale & retail | 2017 |
| Live Big Ltd | Professional & scientific | 2011 |
| Live in Hope Limited | Professional & scientific | 2015 |
| Live in Soho Ltd | Real estate | 2018 |
| Live Life Smiling Limited | Health & social care | 2026 |
| Live Well Community Care CIC | Education | 2025 |
| Living at Home Ltd | Public administration | 2021 |
| Living Concept Interiors Ltd | Wholesale & retail | 2023 |
| Livingston & Company Limited | Households | 1920 |
| Livingwell Pharma Ltd | Wholesale & retail | 2025 |
| LJ Human Factors Limited | Professional & scientific | 2020 |
| LJC Property Investments Ltd | Real estate | 2023 |
| LJM Electricians Ltd | Manufacturing | 2020 |
| LJS Recoveries (Swansea) Ltd | Transport & logistics | 2024 |
| LJW IT Associates Ltd. | Wholesale & retail | 2011 |
| Lkaw Ltd | Professional & scientific | 2025 |
| Lkbs Investments Ltd | Real estate | 2021 |
| LKF Automotive Limited | Wholesale & retail | 2015 |
| Llamors Limited | Construction | 2020 |
| Lland Limited | Construction | 2004 |
| Llandarcy Limited | Professional & scientific | 2006 |
| Llandeilo Developments Ltd | Construction | 2026 |
| Llandewi Group Limited | Construction | 2025 |
| Llanelli Aqua Park Ltd | Arts & recreation | 2025 |
| Llanelli Assets Ltd | Financial services | 2026 |
| Llanelli Community Leisure CIC | Arts & recreation | 2026 |
| Llanelli Container Storage Ltd | Transport & logistics | 2017 |
| Llanelli Self Storage Ltd | Administrative & support | 2015 |
| Llanerch Construction Limited | Construction | 2024 |
| Llanerch Developments Limited | Construction | 2024 |
| Llanfyllin Chinese Ltd | Hospitality | 2022 |
| Llangennith Manors Limited | Other services | 1973 |
| Llangrannog Pubs LLP | | 2023 |
| Llanharan Medical Services Limited | Health & social care | 2026 |
| Llansawel 1963 Limited | Extraterritorial | 2014 |
| Llawr Limited | Wholesale & retail | 2025 |
| LLB Group Limited | Households | 2017 |
| Llcd Limited | Professional & scientific | 2019 |
| LLE Tarw Ltd | Hospitality | 2023 |
| Llewelyn Enterprises Ltd Trading AS DBS Support Ltd | Administrative & support | 2014 |
| Llewelyn Support Services Ltd | Health & social care | 2023 |
| Llewelyn Support Solutions Ltd | Health & social care | 2025 |
| LLJ Locum Ltd | Professional & scientific | 2018 |