| Hoffman Institute UK Limited | Administrative & support | 2001 |
| Hogdeb Properties Ltd | Financial services | 2022 |
| Holly Tree (Walberton) Management Company Limited | Households | 2014 |
| Holmes Place Residents Management Company Ltd | Households | 2025 |
| Home-Start Arun, Worthing & Adur | Health & social care | 2009 |
| Hoult Commercials Ltd | Wholesale & retail | 2021 |
| Hristov & Sander Group Ltd | Information & communication | 2015 |
| Humans Being Ltd | Professional & scientific | 2004 |
| Humphrey Estates Limited | Households | 2018 |
| Hunters Rest Management Company Ltd | Households | 2014 |
| Hynes Property Enterprises Limited | Real estate | 2016 |
| Hynes Property Maintenance Limited | Administrative & support | 2024 |
| Hynes Property Services Limited | Administrative & support | 2017 |
| I Fernando & Company Limited | Professional & scientific | 2018 |
| I.C.S. Electronics Limited | Manufacturing | 1982 |
| Iasis Medical | Health & social care | 2006 |
| Ibuild West Sussex Ltd | Construction | 2024 |
| Imoska Consulting Ltd | Professional & scientific | 2004 |
| Impact Automotive Ltd | Wholesale & retail | 2024 |
| Infinite Luxuries Ltd | Wholesale & retail | 2020 |
| Infonest Limited | Information & communication | 2025 |
| Innovation Pharma Services Limited | Professional & scientific | 2011 |
| Innovative Advantages Ltd | Information & communication | 2021 |
| INOV8 Property Ltd | Construction | 2025 |
| Inside OUT Carpentry and Construction Limited | Construction | 2024 |
| Investment Odyssey Limited | Real estate | 2020 |
| Invictus Security Ltd | Administrative & support | 2015 |
| Isaksson Ltd | Professional & scientific | 2011 |
| J & K C W Developments Limited | Construction | 2006 |
| J Huband Contractors Limited | Construction | 2023 |
| J.Huxtable Electrical and Construction Limited | Construction | 2014 |
| J.L Improvements Limited | Construction | 2026 |
| J.S. Marketing Limited | Wholesale & retail | 1989 |
| J.S. Marketing UK LLP | | 2006 |
| J.S.M. Kitting LLP | | 2006 |
| Jack Smith Limited | Arts & recreation | 2023 |
| JAM Ed-Tech Ltd | Education | 2021 |
| James Skinner Design and Build Limited | Administrative & support | 2024 |
| Japonica Ltd | Wholesale & retail | 2022 |
| JB Horizon Legacy Ltd | Wholesale & retail | 2025 |
| JCI Plant Operations Limited | Construction | 2017 |
| Jennings ROW Facilities Ltd | Professional & scientific | 2015 |
| Jireh Trading Limited | Administrative & support | 2023 |
| Jjir Ltd | Information & communication | 2012 |
| JK Ledger Solutions Limited | Professional & scientific | 2026 |
| JK Technical Support Ltd | Financial services | 2013 |
| JLH Content Ltd | Professional & scientific | 2024 |
| Joanna Shackleton Limited | Education | 2008 |
| Jobev Ltd | Wholesale & retail | 2023 |
| Joer Holdings Limited | Financial services | 2022 |
| Johnson Roofing and Lead Work Limited | Construction | 2026 |
| JPM Car Sales Ltd | Wholesale & retail | 2025 |
| JRB Joinery & Carpentry Limited | Construction | 2019 |
| JRH Forklifts & Machinery Ltd | Manufacturing | 2023 |
| Jsbd Limited | Real estate | 2005 |
| Juniper Arundel Limited | Hospitality | 2022 |
| K&L Cleaning Solutions Ltd | Hospitality | 2023 |
| Keith Marley Limited | Information & communication | 2012 |
| Kelly Consultancy Solutions Limited | Information & communication | 2012 |
| Kenley House Solar Limited | Energy | 2022 |
| KIDS2PONIES Ltd | Agriculture & fishing | 2020 |
| Kiesza Technologies Ltd | Information & communication | 2026 |
| Kingdom Key Solutions Ltd. | Information & communication | 2013 |
| KJS Building Services Ltd | Construction | 2020 |
| KMF Autos Ltd | Wholesale & retail | 2021 |
| Knight & King Ltd | Wholesale & retail | 2019 |
| LA Campania Limited | Hospitality | 2010 |
| Ladygrove Management Limited | Households | 1997 |
| Lamberts Yard Management Limited | Households | 1995 |
| Lamorna Apartments (Management) Limited | Households | 1989 |
| Lanes Counselling Ltd | Health & social care | 2019 |
| Langham Court Management Company Limited | Households | 2007 |
| Lawyers Exchange Limited | Information & communication | 2017 |
| LD Carpentry & Construction Ltd | Manufacturing | 2026 |
| LDS Detailing Ltd | Wholesale & retail | 2021 |
| Learn With Louise Ltd | Education | 2020 |
| Leasonhurst Limited | Households | 1972 |
| Leyla Ltd | Other services | 2020 |
| Libelle Energy Services Limited | Professional & scientific | 2025 |
| Life's Adventures Ltd | Extraterritorial | 2020 |
| Lifeotech Limited | Professional & scientific | 2025 |
| Ligneus Limited | Information & communication | 1998 |
| Lime Avenue Management Company Limited | Households | 2007 |
| Limmer Management Limited | Households | 1996 |
| Liphook Bakery Ltd | Manufacturing | 2009 |
| Lister's Brewery Limited | Manufacturing | 2015 |
| Listers Tech Limited | Information & communication | 2019 |
| Littlestreams Ltd | Information & communication | 2014 |
| Load and Lock Storage Limited | Transport & logistics | 2026 |
| Lockhill 2025 Limited | Financial services | 1988 |
| Lodge and Lake Ltd | Hospitality | 2020 |
| Logistica Accounting Ltd | Professional & scientific | 2020 |
| Longacre Construction Services Limited | Construction | 2011 |
| Lotpart Limited | Wholesale & retail | 2017 |
| Lubbe Landscapes & Contractors Ltd | Administrative & support | 2021 |
| Lufthus Co Ltd | Households | 2024 |
| Luggs Close Management Limited | Real estate | 2004 |
| Luxa Group Ltd | Construction | 2024 |
| Luxwyse Limited | Wholesale & retail | 2024 |
| LWS Marketing Services Limited | Other services | 2012 |