| RAB Execs Limited | London | 2015 |
| Rabtoy Limited | London | 2022 |
| Rachael Leigh Johnson Limited | Southend-On-Sea | 2024 |
| Rachel Wood Dietetics Limited | Oldham | 2020 |
| Radaa Castle Limited | Liverpool | 2025 |
| Radar Alarms Limited | Coventry | 1982 |
| Radecare Ltd | Romford | 2023 |
| Radha Surrey Limited | Surbiton | 2015 |
| Radiant Aesthetics Clinic Ltd | Swindon | 2024 |
| Radiant Healthcare Solutions Limited | Barking | 2019 |
| Radiant Smiles Community Events CIC | London | 2024 |
| Radicatus Ltd | London | 2025 |
| Radkay Solutions Limited | Nantwich | 2024 |
| Radnor Range Limited | Bristol | 2005 |
| Radnor Training & Security Limited | Bristol | 2005 |
| Rafire Consultants Ltd | Hornchurch | 2021 |
| Rahaman Limited | Bedford | 2022 |
| Raheem Global Services Limited | Mitcham | 2024 |
| Rahmaali Solutions Ltd | Ammanford | 2020 |
| Rahul Gupta Consultancy Limited | Banbury | 2016 |
| Raisso House Ltd | Coventry | 2020 |
| Rajapharm Limited | Stoke On Trent | 2019 |
| Rakso Ltd | London | 2026 |
| Raluc Limited | Gosport | 2021 |
| Ramah KER Services Ltd | Bournemouth | 2022 |
| Ramli Fire Limited | Malton | 2012 |
| Ramsier Admin Limited | Kington | 2025 |
| Rannetic (Scotland) Ltd | Kirkcaldy | 2020 |
| Ranu Consulting Limited | Poole | 2023 |
| RAP Mentors Ltd | London | 2024 |
| Rapgile Limited | London | 2024 |
| Rapha Room Ltd | Newport | 2025 |
| Rapid Extinguishers Limited | Glasgow | 1999 |
| Rapid Fire Limited | Cannock | 2021 |
| Rapid Fire Services Limited | Glasgow | 1997 |
| Rapid Lifeline EMS Ltd | Southend-On-Sea | 2025 |
| Rapid Response Fire Solutions Ltd | Hull | 2026 |
| Rapid Response Health Ltd | Milton Keynes | 2025 |
| RAR Consultancy Services Limited | Waterlooville | 2024 |
| Ratson Healthcare Ltd | Mansfield | 2025 |
| Ratyal Healthcare Ltd | Burton-On-Trent | 2024 |
| Ravenswood Technologies UK Limited | London | 2019 |
| RAW Peptides Ltd | Leeds | 2025 |
| RAY of Sunshine Care Ltd | Birmingham | 2020 |
| Rayfire Services Limited | North Shields | 2020 |
| Rayman Hseq Compliance and Training Ltd | Leicester | 2022 |
| Raymond Odion UK Ltd Ltd | Basildon | 2022 |
| Raytheon Mena Group Limited | Harlow | 2016 |
| Raytheon Systems Limited | Harlow | 1946 |
| RB Defence UK Ltd | Lightcliffe, Halifax | 2025 |
| Rbaker Legal Ltd | Blandford Forum | 2023 |
| RBG Safety Services Ltd | Leeds | 2021 |
| Rblighthouse Ltd | Hook | 2022 |
| RC Traffic Ltd | Pontefract | 2016 |
| RCC Care Ltd | London | 2024 |
| Rcct CIC | Harrow | 2020 |
| Rcdtbp Community Interest Company | London | 2019 |
| Rciuk Ltd | London | 2026 |
| RDA and L Services Limited | Billingham | 2020 |
| Rdgb Limited | Chelmsford | 2022 |
| RDH Fire Doors Ltd | Dudley | 2025 |
| RDT Fire&Security Ltd | Benfleet | 2024 |
| Rdthermal Ltd | Pontefract | 2026 |
| RE Consultancy & Training Limited | South Molton | 2012 |
| Re-Engage Solutions Limited | Horsham | 2025 |
| Re.Code Holistics Ltd | Amersham | 2026 |
| Re:Generation Health Limited | London | 2024 |
| Re:Imagine Health Limited | London | 2024 |
| Re:Juvenation Health Limited | London | 2024 |
| Re:Member Health Limited | London | 2024 |
| Re:Mind Health Group Limited | London | 2024 |
| Reach for the Skye CIC | London | 2025 |
| REACH247 Digital Ltd | Chelmsford | 2024 |
| REACH24H Consulting (UK) Ltd | Edgware | 2019 |
| Reacs Health Care Ltd | Leeds | 2024 |
| React Safety Training Limited | Gloucester | 2026 |
| Reactive Fire Services Ltd | Lutterworth | 2023 |
| Reactive Physiotherapy Ltd | Upminster | 2025 |
| READY4CARE Support Ltd | London | 2022 |
| Real Adventures Barnet CIC | New Barnet | 2026 |
| Realgemz Services Limited | Southend-On-Sea | 2026 |
| Realign Therapy and Training Limited | Bury St. Edmunds | 2025 |
| Rear Crew Training Limited | London | 2009 |
| Reardon Consultancy Limited | Eastbourne | 2025 |
| Rebecca Smith Consultancy Limited | Thornton Cleveleys | 2023 |
| Rebecca Ward Healthcare Limited | Northallerton | 2025 |
| Rebot Services Ltd | West Bromwich | 2026 |
| Rebound Diagnostic and Therapeutic Services Limited | Walton-On-Thames | 2020 |
| Rebuildcare Limited | Huntingdon | 2022 |
| Recert Training Solutions Ltd | Doncaster | 2021 |
| Recovair Limited | Andover | 1999 |
| Recovermee Limited | Northampton | 2023 |
| Recovery Boyz Limited | London | 2025 |
| Recovhub Ltd | Leigh-On-Sea | 2024 |
| Recreation Solutions Limited | Holmes Chapel | 2012 |
| Recruit in Care Ltd | Nottingham | 2022 |
| RECRUIT2SUCCESS Ltd | Peterborough | 2023 |
| Recruitment AG Ltd | Cardiff | 2023 |
| Red Button Fire Ltd | Nottingham | 2019 |
| Red Fire Protection Ltd | Birmingham | 2018 |