| Rejuvecare Limited | Health & social care | 2024 |
| REK Global Solutions Limited | Real estate | 2026 |
| Rekam Ltd | Wholesale & retail | 2017 |
| REL Construction Limited | Construction | 2009 |
| REL Integral Hospitality Ltd | Real estate | 2021 |
| REL Integral Investment Limited | Real estate | 2018 |
| REL Integral Properties Ltd | Real estate | 2023 |
| REL Mechanical Services Limited | Professional & scientific | 1972 |
| REL Properties Ltd | Real estate | 2008 |
| Relational UK Ltd | Information & communication | 2018 |
| Relaxing Touch Massage Therapy Ltd | Health & social care | 2026 |
| Relay Properties Limited | Real estate | 1995 |
| Releasd Limited | Administrative & support | 2008 |
| Reliable Asset Management Ltd | Real estate | 2017 |
| Reliable Group Ltd | Real estate | 2011 |
| Reliable Hub Ltd | Wholesale & retail | 2025 |
| Reliable Property Developments Ltd | Construction | 2019 |
| Reliance Big Entertainment (UK) Private Limited | Information & communication | 2012 |
| Reliance Care Services-London Limited | Health & social care | 2026 |
| Reliance Corporation PVT Ltd | Information & communication | 2026 |
| Reliance Entertainment Studios UK PVT Limited | Information & communication | 2020 |
| Reliance Healthcare Services Ltd | Health & social care | 2020 |
| Reliance UK 1 Limited | Wholesale & retail | 2019 |
| Reliant Bridging Finance Ltd | Financial services | 2025 |
| Reliant Building and Developments Limited | Construction | 2015 |
| Reliant Care Limited | Health & social care | 2009 |
| Reliant Care Solutions Ltd | Information & communication | 2010 |
| Reliant Homes Limited | Real estate | 2021 |
| Reliant Housing Limited | Hospitality | 2013 |
| Reliason Solutions Ltd | Information & communication | 2010 |
| Reliasys Ltd | Information & communication | 2012 |
| Relicart Ltd | Wholesale & retail | 2025 |
| Relied on Builders Ltd | Construction | 2019 |
| Relief IT Consultants Ltd. | Information & communication | 2013 |
| Relo-I.T Ltd | Information & communication | 2018 |
| Reluire Properties Ltd | Real estate | 2025 |
| Remember Your Renewal Dates Ltd | Financial services | 2024 |
| Remi Builders Ltd | Construction | 2023 |
| Remi Investments Limited | Financial services | 2017 |
| Remi Trading Limited | Other services | 2006 |
| Remnant Worship Limited | Other services | 2022 |
| Remotioned Technologies Cass Limited | Financial services | 2020 |
| Remotioned Technologies Group Limited | Information & communication | 2020 |
| Remotioned Technologies Opco Limited | Information & communication | 2020 |
| Remove Wanted Level Limited | Other services | 2022 |
| Remus Corporation UK Ltd | Professional & scientific | 2019 |
| REN Associates Ltd | Professional & scientific | 2017 |
| Rena 2 Leisure Services Limited | Hospitality | 2026 |
| Rena Leisure Services Limited | Hospitality | 2002 |
| Rend Eco Ltd | Construction | 2026 |
| Rendezvous Management Limited | Administrative & support | 2024 |
| Renenet Digital Consulting Ltd | Wholesale & retail | 2016 |
| Reneta Ltd | Construction | 2025 |
| Renew Reformer Pilates Limited | Health & social care | 2024 |
| Renewable Capital Limited | Financial services | 2021 |
| RENEWABLES3D Limited | Wholesale & retail | 2025 |
| Renewal Date Reminder Ltd | Financial services | 2024 |
| Renit Solutions Limited | Professional & scientific | 2015 |
| Renk Couture Ltd | Wholesale & retail | 2025 |
| Renmer International Movers Limited | Transport & logistics | 1987 |
| Rennell Property Solutions Limited | Real estate | 2021 |
| Renova House Renovation Limited | Construction | 2009 |
| Renova Living Ltd | Real estate | 2024 |
| Renova Transport Ltd | Transport & logistics | 2026 |
| Renovation Partners Ltd | Construction | 2005 |
| Rent 2 Ride Limited | Transport & logistics | 2021 |
| Rent a Ride Limited | Administrative & support | 2018 |
| Rental Housing Matters Ltd | Real estate | 2022 |
| Renting Vans Ltd | Transport & logistics | 2025 |
| Rentingwala Ltd | Construction | 2026 |
| Rentsy Ltd | Real estate | 2024 |
| Renuka Enterprises Limited | Administrative & support | 2012 |
| Renvic Ltd | Construction | 2025 |
| Reolink Technology UK Limited | Administrative & support | 2026 |
| REP Productions Scandi Ltd | Information & communication | 2015 |
| Repair IT Networks Limited | Other services | 2014 |
| Repair Tech Limited | Wholesale & retail | 2024 |
| Repat Medical Assistance UK Limited | Transport & logistics | 2018 |
| Reply AI Limited | Information & communication | 2026 |
| Reprocopy Printing Limited | Manufacturing | 2021 |
| Reps on Call Limited | Professional & scientific | 2016 |
| Repurpose Property Limited | Real estate | 2021 |
| Reputable Resources Limited | Administrative & support | 2010 |
| Repypra Ltd | Information & communication | 2025 |
| REQ Consultant Limited | Information & communication | 2014 |
| Reqpro Limited | Information & communication | 2013 |
| RES Synd 03 Limited | Administrative & support | 1986 |
| Resdev Tax Consultants Limited | Professional & scientific | 2020 |
| Research Matters of UK Limited | Professional & scientific | 2016 |
| Research Partners Associates Limited | Administrative & support | 2014 |
| Reshad Investment Ltd | Real estate | 2023 |
| Reshape Change Experience Design Ltd | Professional & scientific | 2023 |
| Residall Property Limited | Real estate | 2017 |
| Reside Properties Limited | Real estate | 2011 |
| Residents of Gothic House Limited | Households | 1992 |
| Residwell Limited | Real estate | 2021 |
| Resilience Consulting Limited | Professional & scientific | 2017 |
| Resin Research UK Ltd | Wholesale & retail | 2021 |
| Resistance Pictures Limited | Information & communication | 2018 |
| Resolute R1 Ltd | Wholesale & retail | 2025 |