| Lakeside Motors Mayobridge Limited | Wholesale & retail | 2019 |
| Laketrans Logistics Ltd | Transport & logistics | 2020 |
| Lakeview Bessbrook Ltd | Other services | 2022 |
| Lakeview Design Ltd | Professional & scientific | 2014 |
| Lakeview Playsets Limited | Manufacturing | 2020 |
| Lakeview Plumbing and Heating Ltd | Construction | 2024 |
| Landsurvey Group (Holdings) Ltd | Professional & scientific | 2021 |
| Landsurvey Group Ltd | Professional & scientific | 2020 |
| Lara Lavine Ltd | Manufacturing | 2018 |
| Largex Assets L.P. | | 2017 |
| Larkfield Management Company (N.I.) Limited | Households | 2015 |
| Larkfield Road Apartments Limited | Households | 2007 |
| Laser Electronic Systems Ltd | Manufacturing | 2001 |
| Laser Focused Ltd | Professional & scientific | 2025 |
| Lathberget Construction Ltd | Construction | 2026 |
| Laundry House Group Ltd | Other services | 2026 |
| Laurel & Blossom Wellness Ltd | Real estate | 2024 |
| Laurel Avenue and Mulberry Crescent Management Ltd | Households | 2019 |
| Lauren Taylor Creates Ltd | Arts & recreation | 2021 |
| Lavelle Breeding Services Limited | Agriculture & fishing | 2025 |
| Lavelle Trading Ltd | Wholesale & retail | 2016 |
| Lavery's Fruit & VEG Ltd | Wholesale & retail | 2014 |
| Lawless Estate Agents Ltd | Real estate | 2007 |
| Laytown Limited | Real estate | 2026 |
| Lazrdesigns Ltd | Professional & scientific | 2026 |
| Lazy Hare Ltd | Information & communication | 2025 |
| LBL Holdings Ltd | Real estate | 2015 |
| LC Healthcare Ltd | Health & social care | 2009 |
| LC Tyres Limited | Wholesale & retail | 2019 |
| LCL Developments Ltd | Construction | 2025 |
| LD Haulage Ltd | Transport & logistics | 2014 |
| LDV Camlough Ltd | Hospitality | 2020 |
| LDV Newry Ltd | Hospitality | 2020 |
| LDV Pizza Burger Bar Ltd | Hospitality | 2020 |
| LDV Quays Limited | Hospitality | 2024 |
| LDV Warrenpoint Ltd | Hospitality | 2020 |
| Leak Detector Ltd | Other services | 2014 |
| Leanne Breen Racing Ltd | Arts & recreation | 2020 |
| Learning Space Belfast Ltd | Wholesale & retail | 2016 |
| Learnspark Ltd | Education | 2009 |
| LED Digital Displays Ltd | Wholesale & retail | 2022 |
| Ledi Property Limited | Households | 2019 |
| LEE Garden (NI) Limited | Hospitality | 2016 |
| LEE Garden Newry Ltd | Hospitality | 2022 |
| LEE Nails Ltd | Other services | 2026 |
| Leek Services LP | | 2017 |
| Leestlin Trawlers Limited | Agriculture & fishing | 2010 |
| Legahory Properties Limited | Real estate | 2012 |
| Leinster Boats Limited | Wholesale & retail | 2023 |
| Leinster Environmentals (UK) Limited | Water & waste | 2012 |
| Leiso Property Services Limited | Real estate | 2022 |
| Leisure Industry Services Ltd | Wholesale & retail | 2005 |
| Leitrim Livestock Ltd | Agriculture & fishing | 2023 |
| Leitrim Sawmills Limited | Manufacturing | 1985 |
| Lenfestey & Co Limited | Professional & scientific | 2018 |
| Lennon Livestock Ltd | Agriculture & fishing | 2014 |
| Leode Dog Grooming Ltd | Administrative & support | 2022 |
| Leon Dervan Ltd | Wholesale & retail | 2025 |
| Leonard - Lacy Unlimited | Health & social care | 2010 |
| Lerara Limited | Extraterritorial | 2022 |
| Lesh Security Services Ltd | Professional & scientific | 2012 |
| Lesley Heights Management Company Limited | Households | 2006 |
| Lesley Lodge Apartment Management Company Limited | Households | 2015 |
| Lesohn Limited | Households | 2017 |
| Levelling Equipment Services (NI) Limited | Administrative & support | 2025 |
| Lexford Resources L.P. | | 2017 |
| LFS Enterprises Ltd | Wholesale & retail | 2020 |
| LG Care Limited | Health & social care | 2021 |
| LGK (NI) Limited | Hospitality | 2012 |
| LGM Housing Ltd | Real estate | 2024 |
| LHM (MS) Construction Ltd | Construction | 2016 |
| Licofiba Ltd | Construction | 2019 |
| Life and Time | Health & social care | 2017 |
| Life Style Sports (NI) Limited | Wholesale & retail | 2013 |
| Lifestyle Sports Castlecourt Limited | Wholesale & retail | 2013 |
| Lifestyle Sports Craigavon Limited | Wholesale & retail | 2013 |
| Lifestyle Sports Donegall Place Limited | Wholesale & retail | 2013 |
| Lifestyle Sports Enniskillen Limited | Wholesale & retail | 2013 |
| Lifestyle Sports Richmond Limited | Wholesale & retail | 2013 |
| Lifestyle Toniq Limited | Wholesale & retail | 2020 |
| Light Theatre Company CIC | Arts & recreation | 2020 |
| Lightspark Ltd | Construction | 2024 |
| Lilias Flower Farm Limited | Agriculture & fishing | 2025 |
| Lily Bain Bathrooms & Tiles Ltd | Wholesale & retail | 2016 |
| Limbitless Fitness (NI) Ltd | Arts & recreation | 2021 |
| Lime (N.I.) Ltd | Hospitality | 2015 |
| Limekiln Construction Ltd | Construction | 2019 |
| Limestone Square Management Limited | Households | 2008 |
| Limewood Transport Ltd. | Transport & logistics | 2015 |
| Lindsay Hill Retail Limited | Wholesale & retail | 2014 |
| Line Test Limited | Professional & scientific | 2017 |
| Linen Fields Lurgan Ltd | Households | 2017 |
| Linen Hire Ireland Ltd | Other services | 2025 |
| Link 3 Europe Limited | Administrative & support | 2024 |
| Linport Inter L.P. | | 2015 |
| Linton (N.I) Ltd | Real estate | 2025 |
| Lion Pouches Ltd | Manufacturing | 2025 |
| Lioscarran CD Limited | Households | 2021 |
| Lioscarran Holdings Ltd | Extraterritorial | 2016 |
| LIS ARD Properties Limited | Real estate | 2024 |