| North Walls Residents' Association Limited | Real estate | 1964 |
| Notionplan Limited | Information & communication | 1983 |
| Nottage Inns Limited | Hospitality | 2001 |
| Nsen Enterprises Limited | Administrative & support | 2021 |
| NU Limited | Real estate | 1995 |
| NU Network Products Limited | Information & communication | 1992 |
| Number 11 Chichester Limited | Hospitality | 2019 |
| Numerical Science Limited | Professional & scientific | 1994 |
| Nurture Music Limited | Professional & scientific | 2005 |
| Nutrifocus Limited | Administrative & support | 2004 |
| O'Flanagan PUB Company Limited | Hospitality | 2004 |
| Oaak IT Consulting Limited | Professional & scientific | 2023 |
| Oak Tree Way Limited | Households | 1992 |
| Oakmasters Limited | Manufacturing | 1999 |
| Oast Park Leisure Limited | Arts & recreation | 1999 |
| Old Vicarage Associates Limited | Households | 1990 |
| On-Line Partnership Group Limited | Financial services | 2000 |
| Optical Electronic Components Limited | | 1987 |
| Optigene Limited | Manufacturing | 2008 |
| Oracle Advertising Services Limited | Professional & scientific | 1995 |
| Oriental Emporium (Southern) Limited | Wholesale & retail | 2001 |
| Osborne of Arun Group (Management) Limited | Construction | 1999 |
| Osborne Refrigerators Limited | Manufacturing | 1961 |
| Outbound B2B Limited | Administrative & support | 2021 |
| Overflight Limited | Other services | 2001 |
| Oversal Media Limited | Information & communication | 2012 |
| P & T (Sussex) Limited | | 1987 |
| P. & J. Contractors Limited | Administrative & support | 2006 |
| P.F. Tolhurst Book-Keeping Services Limited | Professional & scientific | 1979 |
| P.G. Bryant Building Contractor Limited | Construction | 2002 |
| P.I.S.D. Ltd. | Information & communication | 1999 |
| Paladone Group Bidco Limited | Financial services | 2021 |
| Palmeira Bodyworks Limited | Wholesale & retail | 2007 |
| Pampurredpets Limited | Wholesale & retail | 1987 |
| Pandrell Limited | Real estate | 1989 |
| Pargeter Engineering Ltd | Manufacturing | 2003 |
| Park Crescent Garage Services Ltd | Wholesale & retail | 2006 |
| Park House Nominees Limited | Construction | 1964 |
| Parkway Motors Limited | Wholesale & retail | 2003 |
| Parmar Staffing Limited | Administrative & support | 2006 |
| Partyplastics LLP | | 2007 |
| Paseec Ltd. | Professional & scientific | 2004 |
| Pass Sport Control Limited | Information & communication | 2003 |
| Paul Bros Limited | Wholesale & retail | 2007 |
| Paul Hopwood Consulting Limited | Professional & scientific | 2006 |
| Paul Wilson Limited | Construction | 2002 |
| Pavilion Glass Co. Limited | Construction | 1987 |
| PCS Solutions Consulting Ltd | Professional & scientific | 2025 |
| PDH Cars Limited | Wholesale & retail | 1974 |
| PDH Vehicles Limited | Professional & scientific | 2009 |
| PDJ Cinemas Limited | Information & communication | 2006 |
| PDL Business Solutions Ltd | Financial services | 2003 |
| Peganol Ltd | Professional & scientific | 2025 |
| Penminster Brown Limited | Construction | 1982 |
| Pentagon Plastics Group Limited | Professional & scientific | 2006 |
| Pentagon Plastics Limited | Manufacturing | 1978 |
| People's Administration Services Limited | Financial services | 1987 |
| People's Health Limited | Extraterritorial | 2017 |
| People's Partnership Holdings Limited | Financial services | 1942 |
| People's Partnership Limited | Financial services | 2016 |
| Peredur Centre | Education | 1966 |
| Pericles Limited | Health & social care | 2002 |
| Peridata Limited | Professional & scientific | 1984 |
| Perren Consulting Limited | Information & communication | 1984 |
| Pet Family Limited | Professional & scientific | 2010 |
| Pet Lamb Holdings Limited | Financial services | 2018 |
| Peter Ferguson Limited | Construction | 2007 |
| Peter Lawson & Co Limited | Professional & scientific | 2000 |
| Peter Smith - Consultant | | 1992 |
| Peter Voigt Limited | Manufacturing | 1960 |
| Peter Wheeler Developments Limited | Construction | 2005 |
| Pharma Hygiene Products Limited | Manufacturing | 1994 |
| Pharmacy 4 U Limited | Wholesale & retail | 2001 |
| Phelan Cleaning Limited | Other services | 1997 |
| Phillip Dart Electrical Limited | Construction | 2006 |
| Philpots Manor School Limited | Education | 1963 |
| Picturedrome Electric Theatre Co Ltd | Information & communication | 2007 |
| Pilot Warehousing Limited | Professional & scientific | 1990 |
| Pipetec Underground Services Limited | Professional & scientific | 1998 |
| Platinum Finance Consultants Limited | Professional & scientific | 2004 |
| Play Mini Limited | Wholesale & retail | 1996 |
| PMG Electrical Services (Southern) Limited | Construction | 1998 |
| Poles and Blinds.Com Limited | Administrative & support | 2006 |
| Polo Splice Limited | Manufacturing | 2007 |
| Portgroom Limited | Wholesale & retail | 1995 |
| Prakashram & Co Limited | Wholesale & retail | 2006 |
| Prana Digital Limited | Professional & scientific | 2019 |
| Precision (Worthing) Limited | Construction | 1999 |
| Prefab Steel Company Limited | Manufacturing | 1999 |
| Premia Marketing Limited | Professional & scientific | 2000 |
| Prestigious Cleaning Services Limited | Other services | 1999 |
| Preston Media Limited | Financial services | 2004 |
| Priestley Way Management Limited | Professional & scientific | 1998 |
| Prime Group Property Ltd | Real estate | 2026 |
| Primegold Consultancy Ltd | Information & communication | 2001 |
| Primezone Property Management Limited | Households | 1988 |
| Private Venture (NZ) Limited | Professional & scientific | 2006 |
| Productions Absolute Limited | Arts & recreation | 1999 |
| Profitable Websites Limited | Information & communication | 2007 |
| Project Ludus Ltd | Information & communication | 2007 |