| Kofe Ltd | Hospitality | 2026 |
| Krismeeke.Com Limited | Arts & recreation | 2003 |
| Kronos A/V Limited | Wholesale & retail | 2002 |
| Kronos Audio Visual (UK) Limited | Wholesale & retail | 2015 |
| Krwc Ltd | Financial services | 2021 |
| L & a Century Travel Ltd | Administrative & support | 2017 |
| L2 Business Solutions Ltd | Professional & scientific | 2026 |
| LAB Aroma Ltd | Information & communication | 2013 |
| LAB PM Services Ltd | Professional & scientific | 2016 |
| Lace - Loughshore Access and Community Enterprise | Other services | 2012 |
| Lade Solutions Limited | Manufacturing | 2020 |
| Lafone House Holdings Ltd | Financial services | 2024 |
| Lafone House Ltd | Hospitality | 2024 |
| Lagan Engineering Ltd | Construction | 2012 |
| Lamix Limited | Wholesale & retail | 1978 |
| Landmark Homes (NI) Limited | Real estate | 2014 |
| Larach (Holdings) Ltd | Financial services | 2022 |
| Larach Buildings Ltd | Construction | 2012 |
| Lars Play Ltd | Construction | 2017 |
| Laser Pro Clean Limited | Administrative & support | 2025 |
| Laurence Loughran Electrics Limited | Construction | 2011 |
| Lawren Laurel Beauty Ltd | Wholesale & retail | 2025 |
| Lazycakes Limited | Manufacturing | 2024 |
| LB Butchers Holdings Ltd | Financial services | 2024 |
| LC Coffee House Ltd | Hospitality | 2023 |
| LC Consulting Ltd | Professional & scientific | 2023 |
| LDM Property Holdings Ltd | Real estate | 2018 |
| Leadain Ltd | Financial services | 2024 |
| Leadain Property Ltd | Real estate | 2025 |
| Leaf Ventures Ltd | Real estate | 2021 |
| Leanna Hospitality Ltd | Hospitality | 2025 |
| Leap Alpha Ltd | Financial services | 2022 |
| Leap Software Ltd | Information & communication | 2021 |
| Lee's Kitchen (Dungannon) Ltd | Hospitality | 2019 |
| Leigheas Ltd | Health & social care | 2026 |
| Leonard Accident Management Ltd | Administrative & support | 2023 |
| LEW Aesthetics Ltd | Health & social care | 2021 |
| Lewton Contracts Ltd | Construction | 2025 |
| Liam Wilson CPD Ltd | Education | 2015 |
| Liam Wilson Ltd | Health & social care | 2013 |
| Liam Wilson Property Limited | Real estate | 2015 |
| Libra Farms Ltd | Agriculture & fishing | 2017 |
| Lifeboat Mission - the | Other services | 2005 |
| Limcon Ltd | Real estate | 2021 |
| Limehill Contracts Ltd | Construction | 2025 |
| Limehill Renovations Limited | Real estate | 2019 |
| Limoges Investments Ltd | Real estate | 2025 |
| Linenfields Open Space Management Company Ltd | Households | 2025 |
| Linergy Limited | Manufacturing | 2016 |
| Link Housing Limited | Real estate | 2013 |
| Linnasoft Limited | Information & communication | 2013 |
| Lisban Farms Ltd | Agriculture & fishing | 2023 |
| Lisban Hire Limited | Wholesale & retail | 2018 |
| Lisboy Pigs Ltd | Agriculture & fishing | 2012 |
| Lisbuoy Farms Limited | Agriculture & fishing | 2017 |
| Lisfearty Group Ltd | Construction | 2025 |
| Lisgallon Properties Limited | Financial services | 2023 |
| Lisglass Limited | Real estate | 1993 |
| Lislap Ltd | Real estate | 2022 |
| Listamlet Developments Limited | Construction | 2021 |
| Listamlet Limited | Professional & scientific | 2014 |
| Little Birdies Products Ltd | Manufacturing | 2022 |
| Little Float Farm Limited | Agriculture & fishing | 2006 |
| Little Mechanical Ltd | Construction | 2025 |
| Little Robin Gifts Ltd | Wholesale & retail | 2022 |
| Live Löyly Ltd | Arts & recreation | 2024 |
| LJ Maxwell Ltd | Financial services | 2023 |
| Lmcc Operations Limited | Information & communication | 2012 |
| LMG Farms Ltd | Agriculture & fishing | 2016 |
| LMT Investments Ltd | Professional & scientific | 2021 |
| Local Where 2 Ltd | Information & communication | 2019 |
| Location Cleaning Contracts Limited | Administrative & support | 2022 |
| Logan TV Limited | Information & communication | 2008 |
| Longfield Farm Ltd | Agriculture & fishing | 2016 |
| Lordyl Ltd | Professional & scientific | 2023 |
| Lough Shore Civils Limited | Construction | 2025 |
| Loughbracken Aesthetics Ltd | Other services | 2024 |
| Loughkelly Holdings Ltd | Real estate | 2020 |
| Loughkelly Ltd | Real estate | 2019 |
| Loughran Mcnally Limited | Health & social care | 2015 |
| Loughshore Autos T/A Quinn's Coach Hire Ltd | Wholesale & retail | 1999 |
| Loughshore Consulting Ltd | Professional & scientific | 2023 |
| Loughshore Contracts Limited | Administrative & support | 2010 |
| Loughshore Plumbing & Electrical Ltd | Construction | 2011 |
| Loughshore Site Service’S & Engineering Limited | Professional & scientific | 2022 |
| Loughshore Spray Foam Insulation Limited | Construction | 2019 |
| Loughview Contracts Ltd | Construction | 2020 |
| Loughview Farms Limited | Agriculture & fishing | 1967 |
| Lower Corr Poultry Farm Ltd | Agriculture & fishing | 2011 |
| Lower Gortgonis House Ltd | Wholesale & retail | 2025 |
| LPM Contractors Ltd | Manufacturing | 2011 |
| Lrst Limited | Agriculture & fishing | 2020 |
| Lrst Property Limited | Real estate | 2024 |
| LS Lifestyle Limited | Arts & recreation | 2025 |
| LS Online Ltd | Arts & recreation | 2017 |
| Lsshndyxgs Limited | Wholesale & retail | 2025 |
| Lswf Limited | Real estate | 2025 |
| Lucky House Ballygawley Ltd | Hospitality | 2024 |
| Lucy Annabella Ltd | Professional & scientific | 2011 |
| Lurgan and District Horse and Cattle Show Society Limited | Extraterritorial | 1988 |