| 0732 Design Studios Limited | Information & communication | 2005 |
| 1 and 2 Lancelot Close Limited | Households | 2005 |
| 1 Ditchling Rise Limited | Real estate | 2022 |
| 1 ST Augustine Road (Littlehampton) RTM Company Limited | Households | 2024 |
| 110 Arundel Road Management Company Limited | Households | 2003 |
| 16 South Terrace Limited | Households | 1990 |
| 172 Goring Road (Worthing) Limited | Households | 2007 |
| 18 Eriswell Road Worthing Management Company Limited | Households | 1987 |
| 19 Gratwicke Road (Worthing) Limited | Households | 1999 |
| 1RED Limited | Manufacturing | 2008 |
| 1YOUWANT Limited | Professional & scientific | 1998 |
| 2 Kingsland Road (Worthing) Limited | Households | 2001 |
| 2 Tone Steel Erection Limited | Wholesale & retail | 2006 |
| 21 Parsons Green Lane Ltd. | Households | 1986 |
| 21ST Century LAN Limited | Information & communication | 2003 |
| 23 Sillwood Road Freeholders Limited | Real estate | 2004 |
| 25 Management Limited | Professional & scientific | 1985 |
| 26 Norfolk Road Littlehampton (Residents Company) Limited | Hospitality | 1988 |
| 3 Calle Palma Limited | Households | 1995 |
| 30 Little London Management Limited | Households | 2005 |
| 30-32 Ludgate Ltd | Real estate | 2025 |
| 36 Carlisle Road Hove Limited | Households | 1978 |
| 4.4 Consulting Ltd | Information & communication | 2021 |
| 42 New Road (Management) Limited | Households | 2003 |
| 4GROUND Media Limited | Information & communication | 2008 |
| 5 Park Road Management Company Limited | Households | 2002 |
| 6 Grand Avenue (Hove) Limited | Households | 2006 |
| 65 Portland Road Management Limited | Households | 1999 |
| 8, Heene Terrace Worthing. Limited | Households | 2002 |
| 802AUTOMATION Limited | Manufacturing | 2005 |
| A & a Accountants Limited | Professional & scientific | 2015 |
| A & S Tooling Limited | Manufacturing | 2002 |
| A C Tidman Limited | Health & social care | 2021 |
| A K Distribution Ltd | Professional & scientific | 2007 |
| A S Wallace Family Butchers Limited | Wholesale & retail | 2006 |
| A Star Scaffolding Southern Limited | Construction | 2007 |
| A. Stacey Limited | Administrative & support | 2006 |
| A.E. (Realisations) (Macclesfield) Limited | | 1964 |
| A.H.Broadbridge and SON Limited | Wholesale & retail | 1965 |
| A.S.H. Electrical (Sussex) Ltd | Construction | 2006 |
| Aarun Accountancy Limited | Professional & scientific | 2002 |
| Able Angel Ltd. | Administrative & support | 2004 |
| Accel Power Supplies Limited | Manufacturing | 1991 |
| Access Control Automation Limited | Other services | 1999 |
| Accord Trading Ltd | Wholesale & retail | 2020 |
| Accountancy and Bookkeeping Bureau Ltd | Professional & scientific | 2000 |
| Accounts Inclusive Ltd | Professional & scientific | 2007 |
| Accuweb (Brighton) Limited | Information & communication | 2008 |
| Acorn Electrical (2008) Limited | Wholesale & retail | 1991 |
| Acorn Electrical Wholesale Limited | Wholesale & retail | 2008 |
| Acorn House Properties Limited | Real estate | 2012 |
| Acoustic Associates Sussex Ltd | Professional & scientific | 2005 |
| Acres Wild Limited | Professional & scientific | 2001 |
| ACS Electrical (Shoreham) Limited | Construction | 2002 |
| Adam Carr Limited | | 1985 |
| Adapt Pharma Ltd | Other services | 2018 |
| Admiral Building & Roofing Ltd | Construction | 2022 |
| Adrian Wood Associates Limited | Manufacturing | 2003 |
| Adur Electrical Limited | Construction | 2007 |
| Advance Sales Services UK Limited | Administrative & support | 2005 |
| Advanced Ergonomic Technologies Limited | Construction | 1993 |
| AEA Dental Ltd | Health & social care | 2014 |
| Affective Sound Ltd | Information & communication | 2006 |
| Affordable Housing Portal Ltd | Construction | 2003 |
| Afriso Eurogauge Limited | Manufacturing | 1962 |
| Agio Consulting Limited | Professional & scientific | 2004 |
| Agio Limited | Professional & scientific | 2004 |
| Agra Haywards Heath Ltd | Hospitality | 2023 |
| Air and Cargo Services (Holdings) Limited | Transport & logistics | 2004 |
| ALC Ventures Group Ltd | Real estate | 2026 |
| Aldridge & Trillwood Limited | Wholesale & retail | 1957 |
| Alex Torok Ltd | Manufacturing | 2007 |
| Alex Wilson Studio Ltd | Professional & scientific | 2025 |
| ALL Kids Ltd | Education | 2002 |
| Allaspex Building Services Limited | Construction | 2005 |
| Allen Tyler Fencing Limited | Construction | 1999 |
| Allergy Therapeutics (Holdings) Limited | Professional & scientific | 1998 |
| Allergy Therapeutics (UK) Limited | Manufacturing | 1998 |
| Allergy Therapeutics PLC | Manufacturing | 2004 |
| Allphotos Limited | Professional & scientific | 1963 |
| Alpha Achievements Ltd | Wholesale & retail | 2025 |
| Alpha SBS Limited | Wholesale & retail | 1987 |
| Amara Andrews Ltd | Professional & scientific | 2018 |
| AMS Trading Co Limited | Wholesale & retail | 1998 |
| Amytech (UK) Limited | Manufacturing | 2007 |
| Anahata | | 1999 |
| Andaman Properties Limited | Real estate | 2005 |
| Andrew Gale Tree Surgery Limited | Agriculture & fishing | 2003 |
| Andrew Leggett Limited | Wholesale & retail | 1985 |
| Andy Long Lighting Limited | Administrative & support | 2005 |
| Anglia Examination Syndicate Limited | Education | 1986 |
| Angmering-On-Sea Lawn Tennis Club Limited | Arts & recreation | 1964 |
| Angola Property Company Limited (the) | Construction | 1972 |
| Anne Germain Ltd | Extraterritorial | 2006 |
| AO Holdings Limited | Financial services | 2017 |
| Apdecor Limited | Wholesale & retail | 2010 |
| Apletree Accountancy Appointments Limited | Administrative & support | 1995 |
| Apollo Taxis Limited | Transport & logistics | 2006 |
| APPS4U Limited | Information & communication | 2016 |
| Aqua-Lak Limited | Wholesale & retail | 2006 |