| RAY Lindon Ltd | Construction | 2025 |
| Rcfc Limited | Professional & scientific | 2021 |
| Rcgf Ltd | Manufacturing | 2011 |
| Rebecca Docherty Psychology Limited | Education | 2021 |
| Rectory Court Bottesford Limited | Households | 1991 |
| Redde Accountancy and Payroll Ltd | Professional & scientific | 2019 |
| Reesons Farm Limited | Manufacturing | 2014 |
| Regcorp Ltd | Financial services | 2020 |
| Regen PHD Ltd | Wholesale & retail | 2024 |
| Regroup Platforms Limited | Information & communication | 2023 |
| Relcatex Ltd | Manufacturing | 2024 |
| Relic Revival Ltd | Professional & scientific | 2024 |
| Remichi Ltd | Extraterritorial | 2017 |
| REN Farming Limited | Agriculture & fishing | 2023 |
| Repair Rebuild Restore Ltd | Wholesale & retail | 2024 |
| Repel Coatings Limited | Construction | 2018 |
| Retsila 360 Limited | Professional & scientific | 2023 |
| RF Smiles Limited | Health & social care | 2025 |
| RFA Haulage Ltd | Transport & logistics | 2025 |
| RHJ Media Limited | Administrative & support | 2011 |
| Rhubarb Fizz Limited | Wholesale & retail | 2019 |
| Riches Capital Ltd | Professional & scientific | 2024 |
| Richwood Cabinetmakers Limited | Manufacturing | 2023 |
| Riding Rwanda Ltd | Administrative & support | 2025 |
| Right Decision Consulting Limited | Professional & scientific | 2015 |
| Risk Strategy Ltd | Professional & scientific | 2024 |
| Riverside Guest House Ltd | Hospitality | 2014 |
| Riverwinds Limited | Professional & scientific | 2006 |
| RJ Harriss Mining Ltd | Mining & quarrying | 2024 |
| Rjbw Solutions Limited | Information & communication | 2011 |
| RJS Bricklaying Contractors Ltd | Construction | 2023 |
| RJS Coaching Ltd | Education | 2021 |
| RJW Property Management Limited | Real estate | 2002 |
| RLS Restoration Limited | Construction | 2006 |
| Roadready Mobile Auto Services Ltd | Wholesale & retail | 2025 |
| ROB Mcgrath Ltd | Professional & scientific | 2013 |
| Robert Cooke of Otway Limited | Agriculture & fishing | 1950 |
| Robert Doughty Consultancy Limited | Professional & scientific | 2000 |
| Robert Gray FUN & Games Limited | Arts & recreation | 2024 |
| Rocard Ltd | Manufacturing | 2011 |
| Rochegrise Ltd | Financial services | 2020 |
| Rock APE Ligistics Ltd | Transport & logistics | 2026 |
| Rock Privacy and AI Governance Consultancy Limited | Professional & scientific | 2026 |
| Root Civils Ltd | Construction | 2025 |
| Rose Electrical & Security Limited | Professional & scientific | 2010 |
| ROY Construction Ltd | Construction | 2026 |
| Royal Air Force College Flying Club Limited(The) | Transport & logistics | 1961 |
| RS Plumbing & Design Limited | Construction | 2008 |
| Ruby Developments Ltd | Construction | 2025 |
| Ruby's Chippy Limited | Hospitality | 2025 |
| Ruby's Plaice Limited | Hospitality | 2025 |
| Rugby Sports Massage and Soft Tissue Therapy Ltd | Health & social care | 2018 |
| Runcible HAT Limited | Professional & scientific | 2018 |
| Rupeikis Limited | Transport & logistics | 2016 |
| Ruppy Trading Ltd | Transport & logistics | 2010 |
| Rushlake Farms Limited | Agriculture & fishing | 1950 |
| Ruskington Dental Practice Ltd | Health & social care | 2010 |
| Ruskington Garden Centre Limited | Wholesale & retail | 2010 |
| Ruskington Off-Lead Ltd | Other services | 2025 |
| Ruskington Youth Centre Limited | Other services | 2013 |
| Rusko Ltd | Hospitality | 2024 |
| Rusko Services Ltd | Households | 2026 |
| Ruthei Limited | Administrative & support | 2018 |
| Rutherford Accountancy Services Ltd | Professional & scientific | 2026 |
| RW Installations Limited | Construction | 2015 |
| S a Accounts Ltd | Professional & scientific | 2022 |
| S D W (Sleaford) Limited | Construction | 2024 |
| S E Hill Limited | Administrative & support | 2018 |
| S G Transport (Sleaford) Limited | Administrative & support | 2012 |
| S L Engineering Ltd. | Manufacturing | 1973 |
| S&P Properties Solutions Limited | Real estate | 2019 |
| S. M. Kent Limited | Construction | 2010 |
| S.J.R. Contractors Ltd | Transport & logistics | 2006 |
| S19 Medical Ltd | Health & social care | 2019 |
| Saachii Group Limited | Financial services | 2026 |
| Saachii Membership Limited | Information & communication | 2026 |
| Saachii Studios Chelsea Limited | Real estate | 2026 |
| Safeict Consultancy Ltd | Information & communication | 2012 |
| Safety Fill Ltd | Wholesale & retail | 2004 |
| Saha Healthcare Limited | Education | 2025 |
| Salvatore Barbers Ltd | Other services | 2024 |
| SAM Crosby Joinery & Building Ltd | Construction | 2019 |
| Sandstorm Consulting Limited | Professional & scientific | 2024 |
| Sanscar Limited | Wholesale & retail | 2022 |
| Sarah Bartholomew Limited | Health & social care | 2016 |
| SAS Transport Ltd | Transport & logistics | 2025 |
| Saunby Motors Ltd | Wholesale & retail | 2021 |
| Sayer Media Ltd | Professional & scientific | 2025 |
| SBS EOT Limited | Administrative & support | 2023 |
| SC7 Property Ltd | Real estate | 2021 |
| Screed Floor Limited | Professional & scientific | 2008 |
| Screed Floor UK Ltd | Construction | 2006 |
| SDN (Sleaford) Limited | Education | 2020 |
| SDN Construction Ltd | Construction | 2024 |
| Sea Cucumber Ltd | Information & communication | 2018 |
| Seasoned Insights and Solutions Ltd | Professional & scientific | 2018 |
| Sebatex UK Ltd | Wholesale & retail | 2019 |
| Securistor Limited | Real estate | 2014 |
| Securistor Self Storage Limited | Real estate | 2017 |
| Securistor Storage Limited | Transport & logistics | 2017 |