| Hivemind AI Limited | Information & communication | 2026 |
| Hmpelectrical Ltd | Construction | 2025 |
| Hoddern House Property Management Ltd | Households | 2018 |
| Hoddern Management Company Limited | Households | 1991 |
| Holiday and Student Cleaning Company Limited | Administrative & support | 2017 |
| Holla Inc UK Limited | Wholesale & retail | 2025 |
| Holt Safety Experts (HSE) Limited | Professional & scientific | 2025 |
| Hostops Ltd. | Wholesale & retail | 2025 |
| Hot Crust Pizza Limited | Hospitality | 2025 |
| Howard Court Peacehaven Residents Association Limited | Households | 1972 |
| HPC Health & Prevention Concepts Ltd | Administrative & support | 2020 |
| HPS Property Development Ltd | Construction | 2018 |
| Hustle Heavy Records Ltd | Information & communication | 2025 |
| Hydrogeine Limited | Administrative & support | 2023 |
| IAN Caley Therapy Ltd | Health & social care | 2024 |
| Ibrowink Boutique Ltd | Other services | 2019 |
| Ideara Ltd | Professional & scientific | 2024 |
| Idris Productions Ltd | Information & communication | 2019 |
| Igneous Entertainment Limited | Information & communication | 2005 |
| Improvising Change Ltd | Professional & scientific | 2015 |
| Independent Light Ltd | Information & communication | 2020 |
| Infinity Cleaning Limited | Other services | 2016 |
| Infinity Consulting & Investments Ltd | Information & communication | 2025 |
| INGLES4U Limited | Education | 2025 |
| Intune Healthcare Ltd | Other services | 2012 |
| Investeck Property Solutions Limited | Real estate | 2018 |
| Iris & Adams Ltd | Wholesale & retail | 2024 |
| Iunblockdrains Ltd | Water & waste | 2018 |
| Iyad Khouri Limited | Hospitality | 2026 |
| J T Welsh Ltd | Construction | 2024 |
| J Weeks Family Cleaners Limited | Administrative & support | 2005 |
| J.Wagstaff(Broadway)Limited | Real estate | 1955 |
| JAM IT & Design Ltd | Information & communication | 2023 |
| JAM Professional Services Ltd | Professional & scientific | 2019 |
| Jamb Construction Limited | Construction | 2018 |
| James Hayday | Professional & scientific | 2010 |
| Jamesons Building and Construction Ltd | Construction | 2021 |
| Jarlands Financial Services Ltd | Financial services | 2023 |
| Jasmine Flowers Seven Dials Limited | Wholesale & retail | 2023 |
| Jcboba Limited | Wholesale & retail | 2022 |
| JD Shannon Accountants Ltd | Professional & scientific | 2013 |
| JG Fast Finish Painting & Decorating Limited | Construction | 2026 |
| JG Pest Control Ltd | Administrative & support | 2026 |
| JK Beck Utilities Limited | Construction | 2017 |
| JMC Residential Ltd | Real estate | 2025 |
| JMS Scaffolding (Southern) Limited | Construction | 2016 |
| John Cremer Limited | Professional & scientific | 2010 |
| Jomy Solutions Limited | Transport & logistics | 2026 |
| JOO Ltd | Wholesale & retail | 2024 |
| Joslufay Ltd | Information & communication | 2025 |
| JS Developments (Hove) Ltd | Construction | 2019 |
| Jubilee Court Limited | Real estate | 2004 |
| Just Dance Ltd | Wholesale & retail | 2025 |
| Just Equity Limited | Extraterritorial | 2019 |
| Justdan Ltd | Transport & logistics | 2025 |
| Kaiko Technologies Ltd | Information & communication | 2025 |
| Kaisie Harry Blair Diggens Limited | Extraterritorial | 2025 |
| Kawa Sushi Limited | Hospitality | 2023 |
| KGA Construction (Sussex) Limited | Extraterritorial | 2021 |
| Kiplings PUB Ltd | Hospitality | 2023 |
| Kirshnikirushan Ltd | Wholesale & retail | 2025 |
| KNT Electrics Ltd | Construction | 2022 |
| Kookie Enterprise Limited | Health & social care | 2014 |
| KS Electrical Engineer Ltd | Construction | 2012 |
| KT Leadwork Ltd | Construction | 2026 |
| L a Bar (Sussex) Limited | Hospitality | 2019 |
| Lansley Consultancy Limited | Professional & scientific | 2015 |
| Laud Properties Limited | Real estate | 2022 |
| LD Wick Ltd | Hospitality | 2026 |
| Leach Projects Ltd | Construction | 2017 |
| Lemonwood Services Limited | Households | 1993 |
| Lenguax English Language Training, Testing and Research Ltd | Information & communication | 2020 |
| LG Sussex Limited | Wholesale & retail | 2013 |
| LH Building Ltd | Construction | 2018 |
| LH Property Investments Ltd | Real estate | 2018 |
| Liam Francis Dance Company Ltd | Arts & recreation | 2025 |
| Light & Loaf Cafe Ltd | Hospitality | 2025 |
| Light Design Services Limited | Professional & scientific | 2017 |
| Lindsay Associates Limited | Professional & scientific | 2024 |
| Lineside Solutions Limited | Extraterritorial | 2014 |
| LIT Homecare Ltd | Transport & logistics | 2024 |
| London Marketings Inc Ltd | Information & communication | 2025 |
| Lost Cats Brighton | Other services | 2006 |
| Love the Dog Limited | Manufacturing | 2021 |
| LS Digital Marketing Ltd | Education | 2018 |
| M Green Plumbing and Heating Ltd | Construction | 2022 |
| M P M a (CCL) Limited | Professional & scientific | 2000 |
| M T P Shipping Company Limited | Transport & logistics | 2005 |
| M.C.Builders (Sussex) Limited | Construction | 2012 |
| M.E.G. Marcantonio Education Group Limited | Education | 2025 |
| MA Monetize Limited | Professional & scientific | 2017 |
| Maac Trading Ltd | Hospitality | 2026 |
| Maadev Limited | Hospitality | 2019 |
| Madison Web Solutions Limited | Information & communication | 2012 |
| Magpie Collectables Ltd | Wholesale & retail | 2022 |
| Maids R US Limited | Other services | 2004 |
| Make Chaos Ltd | Wholesale & retail | 2024 |
| Make My Fantasy Ltd | Administrative & support | 2021 |
| Mama Lou's Ltd | Administrative & support | 2016 |
| Managementum Limited | Professional & scientific | 2025 |