| Red Rhino Monitoring Limited | Administrative & support | 2015 |
| Redstone Software & Research Limited | Information & communication | 1989 |
| Redwood Bank Limited | Financial services | 2015 |
| Reem Medical and Aesthetics Limited | Health & social care | 2025 |
| Refined Residential Ltd | Real estate | 2024 |
| Regen Solutions (U.K) Ltd | Administrative & support | 2020 |
| Regspeky Limited | Construction | 2026 |
| Reisswitz Press Ltd | Wholesale & retail | 2022 |
| Renewelec Electrical Services Ltd | Construction | 2025 |
| Renovision (Hertfordshire) Limited | Construction | 2017 |
| Retail Sourcing & Consultancy Ltd | Professional & scientific | 2016 |
| Retrogear Ltd | Wholesale & retail | 2020 |
| Revamp Discount Limited | Wholesale & retail | 2024 |
| Revival Art UK Ltd | Wholesale & retail | 2013 |
| Revive Corporation Limited | Wholesale & retail | 2025 |
| Revu Online Ltd | Information & communication | 2019 |
| RG Recyling Ltd | Wholesale & retail | 2025 |
| RHC Logistics Ltd | Transport & logistics | 2026 |
| Rhiannon Mills Media Limited | Information & communication | 2010 |
| Rhino Plumbing Drainage Maintenance Solutions Ltd | Water & waste | 2026 |
| Rhonapay Ltd | Administrative & support | 2025 |
| Rich VIS Ltd | Professional & scientific | 2025 |
| Rifumo Company Limited | Health & social care | 2022 |
| Rimisoft Ltd | Wholesale & retail | 2025 |
| Rion Designs Limited | Manufacturing | 1985 |
| Risehazel Property Management Limited | Extraterritorial | 1984 |
| Riverport Developments Limited | Construction | 2016 |
| Riverside (PIX Court) Management Company Limited | Households | 2019 |
| RJC Scenery Limited | Construction | 2022 |
| RK Photo Limited | Wholesale & retail | 2018 |
| Robdom Experts Limited | Health & social care | 2022 |
| Robert John LEE Limited | Extraterritorial | 2022 |
| Robesandblingsbyakokomali Ltd | Professional & scientific | 2025 |
| Robin Baynton Ltd | Information & communication | 2019 |
| Robino Limited | Hospitality | 2025 |
| Robinsons Court Residents Association Limited | Households | 1993 |
| ROC Headlight Ltd | Wholesale & retail | 2021 |
| Rockmill Developments Limited | Construction | 2010 |
| Roger Richards Management Limited | Other services | 2001 |
| Rogue Images Limited | Professional & scientific | 2014 |
| Rolling Essentials Ltd | Wholesale & retail | 2022 |
| Roofboxhireco Ltd | Administrative & support | 2022 |
| Room Packs Limited | Wholesale & retail | 2009 |
| Roomki Ltd | Extraterritorial | 2024 |
| Rosa Bianca Limited | Real estate | 2024 |
| Rose & Stars Ltd | Information & communication | 2024 |
| Roseandthistlemaintenance Ltd | Administrative & support | 2021 |
| Rosebrick Investment Ltd | Real estate | 2024 |
| Rosemount Gardens Limited | Administrative & support | 2024 |
| Round UP Ltd | Professional & scientific | 2022 |
| Roundstone Consulting Ltd | Professional & scientific | 2020 |
| Rowan Homes (NHH) Ltd | Households | 2011 |
| Roxe Bio-Energy Holding Ltd | Financial services | 2024 |
| Roxley Manor (Freehold) Company Limited | Households | 2025 |
| Roxley Manor Management Company Limited | Real estate | 2001 |
| Royale Quarters (SV) Limited | Professional & scientific | 2021 |
| Royston First BID Company Limited | Administrative & support | 2009 |
| RP Aircraft Ltd | Manufacturing | 2019 |
| RS Bike Paints Limited | Manufacturing | 2008 |
| RS Sumal Properties Ltd | Real estate | 2015 |
| RTT Hospital Doctors Ltd | Administrative & support | 2023 |
| Ruby Recovery & Transport Ltd | Transport & logistics | 2025 |
| RUE Essentials Limited | Wholesale & retail | 2024 |
| Rufty Tufty Limited | Professional & scientific | 1989 |
| Run by Singers Ltd | Education | 2001 |
| Rush Green Aviation Limited | Transport & logistics | 1977 |
| Ryman Construction Consultancy Ltd | Professional & scientific | 2019 |
| S & J Property Holdings Limited | Real estate | 2016 |
| S&S Real Estate Properties Ltd | Real estate | 2024 |
| S.I Wiring Services Ltd | Information & communication | 2024 |
| Sadlay Developments Ltd | Construction | 2025 |
| Safeside Medicals Ltd | Health & social care | 2023 |
| Safety Mundo Limited | Education | 2008 |
| SAKA247 Ltd | Real estate | 2016 |
| Sakabi Ltd | Financial services | 2026 |
| Sakal GB Solutions Ltd | Information & communication | 2022 |
| Samans Investments Ltd | Real estate | 2023 |
| Samarket Ltd | Information & communication | 2025 |
| Sandman Designs Limited | Arts & recreation | 2017 |
| Sappodila Ltd | Professional & scientific | 2022 |
| Sarah Graham Art Limited | Administrative & support | 2009 |
| Saray Palace Limited | Hospitality | 2019 |
| Saroye Investments Limited | Real estate | 2021 |
| Sarvapriya Ltd | Wholesale & retail | 2025 |
| Satto Repair Centre UK Limited | Extraterritorial | 2012 |
| Satto Solutions Ltd | Wholesale & retail | 2013 |
| Savage Macbeth Limited | Professional & scientific | 2021 |
| Savvy Consultants Limited | Information & communication | 2010 |
| Sawco Ltd | Other services | 2019 |
| Saxon Mews Management Limited | Real estate | 1989 |
| Saxon Mews Phase II Management Limited | Real estate | 1989 |
| SB Grill Ltd | Hospitality | 2025 |
| SBR Group Limited | Real estate | 2017 |
| SC3 Developments Ltd | Construction | 2024 |
| Scale Careers Management Ltd | Administrative & support | 2020 |
| Scene Logic Limited | Administrative & support | 2025 |
| Screamo Corp Limited | Wholesale & retail | 2026 |
| Screamo Limited | Information & communication | 2023 |
| Seba Enterprises Limited | Wholesale & retail | 1987 |
| Secret Level Studios Ltd | Information & communication | 2014 |