| Quantum Accounting Solutions Ltd | Professional & scientific | 2024 |
| Quantum Business Dynamics Limited | Professional & scientific | 2003 |
| Quantum Crew Ltd | Administrative & support | 2025 |
| Quantum Living Ltd | Construction | 2021 |
| Quantumeye Limited | Information & communication | 2025 |
| Quapla Ltd | Health & social care | 2025 |
| Quay Court (Shoreham) Limited | Households | 1995 |
| Qubed Construction Ltd | Construction | 2019 |
| Queensbury and Regency Limited | Households | 1999 |
| Queensbury Coffee Ltd | Hospitality | 2017 |
| Quick Locksmith Ltd | Other services | 2018 |
| Quickshift Couriers Ltd | Administrative & support | 2013 |
| Quiet Assembly Ltd | Professional & scientific | 2025 |
| Quiet Ground Solutions CIC | Health & social care | 2026 |
| Quill Dynamics Limited | Public administration | 2025 |
| Quintas Energy UK Ltd | Administrative & support | 2010 |
| Quintas Power UK Holdco Limited | Financial services | 2024 |
| Quinze Holdings Limited | Professional & scientific | 2010 |
| Quirke Collective Ltd | Wholesale & retail | 2025 |
| Quiz Dog Ltd | Arts & recreation | 2024 |
| Qupon Ltd | Construction | 2021 |
| Qwazar LLP | | 2014 |
| R & a Griffiths Properties Limited | Construction | 1999 |
| R & C Foods Ltd | Manufacturing | 2025 |
| R & M Marketing Limited | Professional & scientific | 2002 |
| R & R Electrical (Sussex) Limited | Wholesale & retail | 2012 |
| R & S Barnes Limited | Wholesale & retail | 2004 |
| R Addams Limited | Information & communication | 2024 |
| R E Howarth Consultancy Ltd | Professional & scientific | 2022 |
| R NYE Construction Limited | Construction | 2014 |
| R R Developments (Sussex) Ltd | Construction | 2007 |
| R S Tanner Ltd | Other services | 2003 |
| R T Bridges Limited | Information & communication | 2003 |
| R Way Properties Ltd | Construction | 2025 |
| R.C. Bather Limited | Arts & recreation | 1994 |
| R.G.Plastering Ltd | Construction | 2015 |
| R.H. Contractors Limited | | 1973 |
| R.J.Pictures Ltd | Information & communication | 2024 |
| R.W. Hove Interiors Ltd. | Construction | 2020 |
| RA Building Constructions Ltd | Construction | 2013 |
| Racepoint Ventures Ltd | Professional & scientific | 2023 |
| Radiantfit Ltd | Other services | 2025 |
| Radiantis Limited | Education | 2018 |
| Radical Spa Developments Ltd | Real estate | 2016 |
| Radicl Ltd | Information & communication | 2024 |
| Raffi & Reza Ltd | Hospitality | 2022 |
| Rafiq and Sons Construction Limited | Construction | 2026 |
| RAG Medical Ltd | Health & social care | 2024 |
| Ragga Management Ltd | Professional & scientific | 2020 |
| Rahman Brothers (Brighton) Limited | Wholesale & retail | 2022 |
| Raja Shah Investments Limited | Real estate | 2019 |
| Rakell Limited | | 1973 |
| Rakhana Limited | Professional & scientific | 2018 |
| Rakk Property Limited | Real estate | 2023 |
| Ralan Ltd | Wholesale & retail | 2017 |
| Raldent Investments Limited | Health & social care | 2024 |
| Raldent Limited | Health & social care | 2021 |
| Ramadan Project Office Solutions Limited | Professional & scientific | 2013 |
| Ramcare Limited | Professional & scientific | 1996 |
| Ramsey Solar Limited | Energy | 2015 |
| Randalls Sports Turf and Garden Contractors Limited | Administrative & support | 2016 |
| Random Precision Restaurants Ltd | Hospitality | 2018 |
| Ranelagh Home Improvements Limited | Construction | 2008 |
| Rank YOU Higher Digital Marketing Ltd | Information & communication | 2020 |
| Ranley Consulting Ltd | Professional & scientific | 2022 |
| Rapart Ltd | Information & communication | 2009 |
| Raphael Road Limited | Households | 1998 |
| Rapid Consulting (UK) Ltd | Administrative & support | 2011 |
| Rapid Films Limited | Information & communication | 2011 |
| Rapid Sussex Care Company Limited | Health & social care | 2020 |
| Rapid Training Solutions Ltd | Education | 2025 |
| Rapidinsure.Co.Uk Limited | Information & communication | 1999 |
| RAQ Estate Management Limited | Households | 2018 |
| Rare Business Limited | Professional & scientific | 2010 |
| Rarekind Records Ltd | Wholesale & retail | 2010 |
| Rasplastering Ltd | Construction | 2023 |
| Rastushire Limited | Households | 1967 |
| Rationalite Group Ltd | Professional & scientific | 2020 |
| Ravenlane Limited | Real estate | 2021 |
| Ravenswood Developments Limited | Construction | 2017 |
| Ravenzone Limited | Households | 1987 |
| RAW Chiropractic Limited | Administrative & support | 2018 |
| RAW Cutz Limited | Information & communication | 2012 |
| RAW Grappling Ltd | Arts & recreation | 2024 |
| RAW Instinct Ltd | Arts & recreation | 2015 |
| RAW Materials Collective Ltd | Arts & recreation | 2021 |
| RAW Performance Gym Ltd | Arts & recreation | 2020 |
| RAW Worldwide Limited | Wholesale & retail | 2025 |
| Rawlings Creative LLP | | 2025 |
| Raybay Limited | Wholesale & retail | 2003 |
| Raygun Music Management Limited | Information & communication | 2006 |
| Raygun Publishing Limited | Information & communication | 2013 |
| Raygun Records Ltd | Information & communication | 2014 |
| Raylink Business Consults Ltd | Information & communication | 2023 |
| Raymond George Consultancy Limited | Administrative & support | 2016 |
| RAZ Trading Redhill Ltd | Hospitality | 2016 |
| RB Renovations Limited | Real estate | 2023 |
| RBS Client Management Ltd | Construction | 2019 |
| RC LND & Co Ltd | Arts & recreation | 2025 |
| Rcdent Limited | Health & social care | 2025 |