| Quirky Antiques Limited | Wholesale & retail | 2013 |
| Quoitings (Marlow) Management Company Limited | Households | 2001 |
| QVV Engineering UK Limited | Manufacturing | 2024 |
| R a Hughes Rheumatology Limited | Health & social care | 2011 |
| R and E Builders Limited | Construction | 2016 |
| R N Ahmed Limited | Financial services | 2013 |
| R W Clarke Limited | Professional & scientific | 2009 |
| R&F Alternative Investments Limited | Financial services | 2020 |
| R&F Consultancy Limited | Administrative & support | 2018 |
| R&F Group Holdings Limited | Financial services | 2026 |
| R&M Construction Services Limited | Construction | 2000 |
| R&N Property Services Ltd | Real estate | 2021 |
| R&S Commercial Services Limited | Wholesale & retail | 2006 |
| R&S Recovery Services Limited | Wholesale & retail | 2006 |
| R.B. Services (Buckinghamshire) Limited | Wholesale & retail | 2017 |
| R.H.B Homes Ltd | Construction | 2021 |
| R.J. Beauty Limited | | 1988 |
| RA Properties (Global) Limited | Real estate | 2024 |
| Rabg Ltd | Professional & scientific | 2019 |
| Racing Past Media Ltd | Information & communication | 2020 |
| Radex Construction Ltd | Construction | 2012 |
| Ragsto Limited | Manufacturing | 2014 |
| Ragstone Road RTM Company Limited | Households | 2008 |
| Rainbow FIX Limited | Construction | 2007 |
| Ransome Developments Limited | Real estate | 2021 |
| Rapid Accounting Services Limited | Professional & scientific | 2001 |
| Rare Snacks Ltd | Manufacturing | 2013 |
| Ratestep Property Management Limited | Households | 1989 |
| Rauschert Limited | Professional & scientific | 2011 |
| Ravenser Films Ltd | Professional & scientific | 2015 |
| RAY Drive Mansions (Maidenhead) Management Company Limited | Households | 1996 |
| RAY Mead Residents (Maidenhead) Limited | Households | 1973 |
| Raymond Reed Executive Services Limited | Professional & scientific | 1986 |
| RB System Solutions Ltd | Information & communication | 2023 |
| RB2C Ltd | Professional & scientific | 2020 |
| Rbbt Ltd | Professional & scientific | 2023 |
| Rblm Properties Limited | Real estate | 2024 |
| RBS Associates (Independent Financial Advisers) Limited | Extraterritorial | 2002 |
| RDMC2 Ltd | Extraterritorial | 2022 |
| REA Solutions Ltd | Wholesale & retail | 2018 |
| Real Construction London Limited | Construction | 2024 |
| Reality Limited | Administrative & support | 1996 |
| Realm Consulting Ltd | Professional & scientific | 2023 |
| Realtime Europe Ltd | Information & communication | 2010 |
| Rebellion Beer Company Limited | Manufacturing | 1997 |
| Rebourne Ltd | Professional & scientific | 2025 |
| Rechem Ltd | Water & waste | 2011 |
| Reckoner Audit Ltd | Professional & scientific | 2021 |
| Reckoner UK Investments Ltd | Real estate | 2023 |
| Recruitment Capital Partners LLP | | 2013 |
| Recruitment Marketing Group Ltd | Professional & scientific | 2025 |
| Recruitment Strategies Limited | Administrative & support | 2017 |
| Red 8 Entertainment Ltd | Information & communication | 2016 |
| Red Coral Consulting Limited | Other services | 2011 |
| Red Kite Advisory Services Ltd | Administrative & support | 2011 |
| Red Mobile Box Limited | Other services | 2017 |
| Red Robin Consultants Ltd | Professional & scientific | 2022 |
| Red Thread Consulting Limited | Professional & scientific | 2012 |
| Reddunet Limited | Professional & scientific | 2026 |
| Reddy House Wycombe Limited | Households | 2016 |
| Redgrave Sports Centre Marlow Limited | Arts & recreation | 2013 |
| Redhead Music Limited | Information & communication | 1995 |
| Redpanda Fulfilment Limited | Transport & logistics | 2011 |
| Redrock Energy Limited | Professional & scientific | 2014 |
| Reformist Ltd | Real estate | 2004 |
| Relish Agency Limited | Professional & scientific | 2018 |
| Renasco Retreats Limited | Health & social care | 2025 |
| Renegade Collection Ltd | Professional & scientific | 2019 |
| Reserved Dining Limited | Extraterritorial | 2016 |
| Residents Management (NO.12) Limited | Households | 1985 |
| Resolute Brands (UK) Limited | Wholesale & retail | 2022 |
| Resolve Operate Consulting Limited | Professional & scientific | 2021 |
| Rest Assured Consultancy Ltd | Professional & scientific | 2022 |
| REV F Marketing Limited | Professional & scientific | 2019 |
| Revere Agency Ltd | Administrative & support | 2013 |
| Revir Tech Ltd | Manufacturing | 2017 |
| Rewilding Africa CIC | Education | 2022 |
| Rewired Limited | Professional & scientific | 2005 |
| REX Procter & Partners LLP | | 2006 |
| REX SLU Ltd | Manufacturing | 2023 |
| RFH Building Services Limited | Construction | 2014 |
| RFL Wellbeing Group Ltd | Arts & recreation | 2021 |
| RFL Wellington Ltd | Health & social care | 2023 |
| RGB Photography Limited | Professional & scientific | 2021 |
| RHA Design Ltd | Professional & scientific | 2020 |
| Rhino Engineering Services Limited | Professional & scientific | 2019 |
| RHM Consult Ltd | Construction | 2018 |
| Richard Marris Consulting Ltd | Professional & scientific | 2019 |
| Richardson Jones Limited | Professional & scientific | 2003 |
| Richter Associates (Exeter) Limited | Professional & scientific | 2019 |
| Richter Associates (Technologies) Limited | Information & communication | 2022 |
| Ridgeway Software Limited | Information & communication | 2008 |
| Ridgmont Court (Management) Limited | Households | 1983 |
| Ridhi Sidhi Limited | Wholesale & retail | 2013 |
| Rights International Ltd | Information & communication | 2026 |
| Rinnova Recruitment Limited | Administrative & support | 2021 |
| Rise Coaching and Consulting Ltd | Professional & scientific | 2024 |
| Risingmoon Property Management Limited | Households | 1987 |
| Risto's Farm Supplies Limited | Wholesale & retail | 2014 |
| Ritua Ltd | Manufacturing | 2025 |