| Reactivate IQ Limited | Education | 2025 |
| Reactive Fusion Ltd | Manufacturing | 2022 |
| Reactor Maintenance Limited | Administrative & support | 2023 |
| Reactor Maintenance Services Limited | Manufacturing | 2017 |
| Reactor Online Limited | Professional & scientific | 2021 |
| Reactor Projects Ltd | Arts & recreation | 2007 |
| Read Catering Ltd | Hospitality | 2018 |
| Read OUR Policies Ltd | Wholesale & retail | 2020 |
| Reads Renovations Limited | Real estate | 2025 |
| Ready Care Private Limited | Health & social care | 2018 |
| Ready Cleanse Ltd | Administrative & support | 2019 |
| Ready EYE Limited | Wholesale & retail | 2025 |
| Ready Lets Go Ltd | Real estate | 2013 |
| Ready Lets Ltd | Real estate | 2023 |
| Ready Mixed Concrete Project Management Limited | Construction | 2014 |
| Ready Train Go Ltd | Arts & recreation | 2020 |
| READY2CLEAR Ltd | Water & waste | 2025 |
| Readygrid Limited | Wholesale & retail | 1992 |
| Reakut's Motor Repairs Limited | Wholesale & retail | 2026 |
| Real Accommodation (EM) Ltd | Real estate | 2024 |
| Real Brewing PUB Company Limited | Hospitality | 2004 |
| Real Capital Insight Ltd | Real estate | 2022 |
| Real Coaching Limited | Arts & recreation | 2022 |
| Real Corporation Limited | Real estate | 2023 |
| Real Difference Ltd | Extraterritorial | 2009 |
| Real Estate Developments Ltd | Other services | 2025 |
| Real Estate Economics Limited | Real estate | 2003 |
| Real Estate Management Consulting Ltd | Real estate | 2021 |
| Real Estate Nottingham Ltd | Real estate | 2025 |
| Real Fake Company Ltd | Wholesale & retail | 2023 |
| Real Life Logistics Ltd | Transport & logistics | 2026 |
| Real Lives Community Interest Company | Health & social care | 2012 |
| Real Living Property Investment Ltd | Real estate | 2022 |
| Real S8 Ltd | Real estate | 2019 |
| Real Talk Central With Ireti CIC | Education | 2025 |
| Real Time Location Systems Ltd | Wholesale & retail | 2024 |
| Real Tonic Ltd | Professional & scientific | 2019 |
| Reality Brewing Limited | Manufacturing | 2009 |
| Reality Education and Overseas Travel Limited | Education | 2023 |
| Realiving Wings Decoration Limited | Construction | 2023 |
| Really Awesome Properties Ltd | Extraterritorial | 2023 |
| Really Care Ltd Services Ltd | Other services | 2018 |
| Really Security Limited | Information & communication | 2018 |
| Realm Consult Ltd | Professional & scientific | 2025 |
| Realmwalker Studios Limited | Information & communication | 2025 |
| Realtorix Ltd | Financial services | 2025 |
| Realtorixhmo Ltd | Real estate | 2025 |
| Realty Wealth Ltd | Real estate | 2020 |
| Realwood Homes Ltd | Hospitality | 2024 |
| Ream International Limited | Wholesale & retail | 2022 |
| Rebalex Limited | Water & waste | 2004 |
| Rebe Ltd | Construction | 2021 |
| Rebeca Restaurant Limited | Hospitality | 2026 |
| Rebeca’S Space Ltd | Wholesale & retail | 2024 |
| Rebecca Dawe Photography Limited | Professional & scientific | 2003 |
| Rebecca Mcballantine Limited | Extraterritorial | 2017 |
| Rebecca P Cann Ltd | Wholesale & retail | 2026 |
| Rebekah Galligan Enterprises Ltd | Professional & scientific | 2022 |
| Rebel City Resources Ltd | Information & communication | 2025 |
| Rebel City Roasters Ltd | Manufacturing | 2026 |
| Rebel Clothing Company Limited | Wholesale & retail | 2003 |
| Rebel Developments Limited | Real estate | 2009 |
| Rebel Group Holdings Limited | Financial services | 2026 |
| Rebel Recruiters Ltd | Extraterritorial | 2017 |
| Rebel Recruitment Limited | Administrative & support | 2015 |
| Rebel Sparks C.I.C. | Health & social care | 2019 |
| Rebel Wakefield Limited | Wholesale & retail | 2026 |
| Rebella Properties Ltd | Real estate | 2025 |
| Rebellion Syndicate Ltd | Wholesale & retail | 2026 |
| Rebellis Limited | Professional & scientific | 2025 |
| Rebelo Brito Limited | Health & social care | 2016 |
| Rebirth Studios Digital Ltd | Professional & scientific | 2025 |
| Rebirth Wellness Journey -Yoga Breatwork Nutrition Limited | Hospitality | 2025 |
| REC Enterprises Ltd | Construction | 2025 |
| REC Maintenance & Transport Limited | Wholesale & retail | 2025 |
| Reclaimed Roof Tiles & Moore Ltd | Construction | 2020 |
| Reco Recovery Ltd | Transport & logistics | 2025 |
| Recon Services Ltd | Other services | 2017 |
| Reconnect Care & Support Ltd. | Health & social care | 2022 |
| Reconnect Health-Services Ltd | Health & social care | 2018 |
| Record Electrical Associates Limited | Manufacturing | 2003 |
| Recover Pro Ltd | Wholesale & retail | 2021 |
| Recovery + Ltd | Water & waste | 2025 |
| Recovery Healthcare Limited | Health & social care | 2016 |
| Recresco Limited | Water & waste | 2000 |
| Recruit in Care Ltd | Public administration | 2022 |
| Recruit With ME. Run With ME. Ltd | Professional & scientific | 2020 |
| Recruit Works Limited | Extraterritorial | 2017 |
| Recruiting Healthcare Limited | Administrative & support | 2020 |
| Recruitment & Selection Specialists Ltd | Administrative & support | 2021 |
| Recruitment Wolf Limited | Administrative & support | 2017 |
| Rectory Road Properties Limited | Real estate | 2006 |
| Recycle Services (UK) Ltd | Water & waste | 2010 |
| Recycle Shop Limited | Water & waste | 2009 |
| Recycling Equipment Services Limited | Manufacturing | 2009 |
| Red Alert (2015) Limited | Financial services | 2014 |
| Red Alert Services Limited | Administrative & support | 2001 |
| Red Alpha Management Ltd | Professional & scientific | 2023 |
| Red and Nero Cars Ltd | Transport & logistics | 2026 |
| Red Bamboo Business Consultancy Ltd | Professional & scientific | 2025 |