| Rdkds Limited | Administrative & support | 2010 |
| Rdms Holdings Limited | Financial services | 2022 |
| RDR Consultancy Services Limited | Professional & scientific | 2020 |
| RDT Carpentry & Joinery Limited | Construction | 2015 |
| REACH24H Consulting (UK) Ltd | Public administration | 2019 |
| Reading Exchange Limited | Wholesale & retail | 2018 |
| Ready 2 Go (London) Ltd | Hospitality | 2017 |
| Ready Willing & Able Ltd | Professional & scientific | 2011 |
| Reafrica Limited | Information & communication | 2013 |
| Reaki London Limited | Professional & scientific | 2024 |
| Real Deck International Ltd | Information & communication | 2017 |
| Real Estate Asset Management Ltd | Real estate | 2019 |
| Real Estate Properties London Ltd | Real estate | 2020 |
| Real G.M. Property Limited | Real estate | 2011 |
| Real Music Academy Limited | Arts & recreation | 2019 |
| Real Property Services Limited | Real estate | 2018 |
| Real Steel Solutions Ltd | Professional & scientific | 2019 |
| Real World Ready Limited | Education | 2025 |
| Realeyes Global Ltd | Information & communication | 2021 |
| Reality (UK) Limited | Health & social care | 2011 |
| Realty EYE Limited | Real estate | 2015 |
| REB Hershel Liska Ltd | Real estate | 2024 |
| REB Yisroel Baal Shem TOV Limited | Real estate | 2025 |
| Rebecca Lenkiewicz Limited | Arts & recreation | 2018 |
| Reborn Beauty Ltd | Other services | 2023 |
| Rebuild Your Life Ltd | Health & social care | 2012 |
| RECONNECT2CONNECT Ltd | Professional & scientific | 2022 |
| Recreation Zone Ltd | Hospitality | 2025 |
| Recruitbright Limited | Information & communication | 2019 |
| Red Advance Limited | Professional & scientific | 2005 |
| Red Capital Ltd | Administrative & support | 2007 |
| Red GAS Consultancy Limited | Administrative & support | 2018 |
| Red Lotus Holdings Limited | Financial services | 2025 |
| Red Melon Investments Limited | Real estate | 2021 |
| Red Rose Cottage Ltd | Real estate | 2020 |
| Red Seaweed Ltd | Wholesale & retail | 2022 |
| Red Smart Modesty Ltd | Construction | 2017 |
| Red Stairs Cafe Ltd | Hospitality | 2023 |
| Redbrick Ground Ltd | Real estate | 2026 |
| Redbridge Cars Limited | Transport & logistics | 2025 |
| Redcircle Pest Control Limited | Other services | 2014 |
| Redendale Limited | Real estate | 1979 |
| Redesign LDN Limited | Professional & scientific | 2018 |
| Redford Designs Limited | Professional & scientific | 2022 |
| Redgold Investments Limited | Professional & scientific | 2000 |
| Redleaf Glore Ltd | Wholesale & retail | 2025 |
| Redline Limited | Administrative & support | 1998 |
| Redline Transport Consultant Limited | Transport & logistics | 2025 |
| Redluco Ltd | Professional & scientific | 2013 |
| Redmount Estates Limited | Real estate | 2016 |
| Redstone Technologies Ltd | Information & communication | 2012 |
| Redthunderbolt London Limited | Construction | 2016 |
| Redwave Housing Ltd | Professional & scientific | 2026 |
| Redwood Pharmacy Limited | Wholesale & retail | 2006 |
| Reed Retail Ltd | Wholesale & retail | 2024 |
| Reel Leisure Time Limited | Arts & recreation | 2001 |
| Rees Rentals Limited | Administrative & support | 2024 |
| Reeson Care Homes Limited | Information & communication | 2000 |
| Reeves Investments Ltd | Real estate | 2019 |
| Refi Rail Services Ltd | Construction | 2016 |
| Refik Limited | Professional & scientific | 2011 |
| Regad Properties Limited | Real estate | 1999 |
| Regal Court Residents Management Company Limited | Households | 2005 |
| Regal First Limited | Other services | 2021 |
| Regal Heating and Plumbing Limited | Construction | 2012 |
| Regal Sounds Ltd | Information & communication | 2025 |
| Regent Petroleum UK Ltd | Other services | 2006 |
| Reggae Spice Limited | Hospitality | 2011 |
| Regina Court Limited | Construction | 1980 |
| Reglus Technologies Ltd | Manufacturing | 2018 |
| Rehan Business Advisory Ltd | Professional & scientific | 2026 |
| Rehan Hair Stylist Ltd | Other services | 2024 |
| Reichmann Properties Ltd | Real estate | 1998 |
| Reilly Construction Holdings Limited | Professional & scientific | 2006 |
| Reinab Care Limited | Health & social care | 2012 |
| Reka Constructions Ltd | Construction | 2026 |
| Reklaw IP Ltd | Administrative & support | 2026 |
| Reklaw Ltd | Arts & recreation | 2014 |
| REL Capital Estates Ltd | Real estate | 2025 |
| REL Trading Group Ltd | Wholesale & retail | 2018 |
| Relburn Limited | Professional & scientific | 2024 |
| Reldin Limited | Professional & scientific | 2024 |
| Reldor Limited | Professional & scientific | 2024 |
| Reliable Plumbing & Electric Ltd | Construction | 2025 |
| Reliant Fire & Security Ltd | Administrative & support | 2022 |
| Reliant Property Services Group Ltd | Other services | 2022 |
| Relish Food Services Ltd | Hospitality | 2024 |
| Rellim Limited | Real estate | 2009 |
| Remass Ltd | Wholesale & retail | 2020 |
| Remember That Whisky Limited | Wholesale & retail | 2024 |
| Remiast Ltd | Information & communication | 2025 |
| Removal Solutions Ltd | Transport & logistics | 2014 |
| Renatus Rail Ltd | Professional & scientific | 2023 |
| Renea Property Investments Ltd | Real estate | 2021 |
| Renegade Films Limited | Information & communication | 1979 |
| Rens Kitchen Ltd | Hospitality | 2004 |
| Rent a Space London Ltd | Real estate | 2024 |
| Rent- a- Home (London) Limited | Real estate | 2022 |
| Rental Solutions Limited | Professional & scientific | 2016 |
| Rentiu Laur Trans Ltd | Transport & logistics | 2020 |