| Ravenco 1 Limited | Financial services | 2025 |
| Ravenco 2 Limited | Financial services | 2025 |
| Ravenco 3 Limited | Financial services | 2025 |
| Ravenco 4 Limited | Financial services | 2025 |
| Ravensmead Limited | Construction | 1989 |
| RAW Kids Gymnastics Grantham Limited | Arts & recreation | 2025 |
| Raxel Storage Systems Limited | Manufacturing | 1982 |
| RAY Tuppa Engineering Ltd | Professional & scientific | 2025 |
| Rayment Creative Ltd | Professional & scientific | 2011 |
| RC Finance & Accounting Ltd | Professional & scientific | 2021 |
| Rccg New Hope Assembly, Grantham | Other services | 2024 |
| Rcmf Transport Ltd | Transport & logistics | 2026 |
| Rdeb Consulting Limited | Professional & scientific | 2014 |
| RDF Groundwork and Construction Limited | Construction | 2023 |
| Reach Financial Services Limited | Financial services | 2001 |
| Read's Worldwide Limited | Transport & logistics | 2000 |
| Readysale Limited | Wholesale & retail | 1967 |
| Real Tree Solutions Limited | Agriculture & fishing | 2008 |
| Realog Limited | Hospitality | 2003 |
| Receiptwise Limited | Information & communication | 2026 |
| Recruiting Solutions (East Midlands) Limited | Administrative & support | 2003 |
| Recruitme (Grantham) Limited | Administrative & support | 2016 |
| Rectory Land Company Limited | Financial services | 2016 |
| Red Cherry Retail Ltd | Wholesale & retail | 2014 |
| Red Homes Healthcare Grantham Limited | Health & social care | 2017 |
| Red Homes Healthcare Limited | Health & social care | 2009 |
| Red Kite Studio Ltd | Arts & recreation | 2023 |
| Red Lion Inn Caythorpe Ltd | Hospitality | 2025 |
| Red Rhino Crushers (UK) Limited | Manufacturing | 2009 |
| Red Robin Homes Limited | Construction | 2014 |
| Red Roofs Midlands Limited | Health & social care | 2012 |
| Red Squirrel Ventures Limited | Information & communication | 2004 |
| Red Welders Ltd | Construction | 2021 |
| Redbrook Mill (Barnsley) Management Limited | Real estate | 2013 |
| Redemics Cultural Intelligence Services Limited | Education | 2007 |
| Redshank Limited | Financial services | 1997 |
| Reduced Carbon Fuels Limited | Water & waste | 2024 |
| Reecker Ltd | Wholesale & retail | 2021 |
| Reflections Practice Limited | Health & social care | 2005 |
| Regents Court Limited | Other services | 1989 |
| Reids Effective Solutions Ltd | Health & social care | 2024 |
| Reignite Heating & GAS Services Ltd | Construction | 2024 |
| Rejuvenated by Kirov Ltd | Health & social care | 2025 |
| Relish Hospitality Ltd | Administrative & support | 2025 |
| Reloaded Waffle Limited | Hospitality | 2019 |
| Remote Solar Power Systems Ltd | Manufacturing | 2024 |
| Renata Terjeki Ltd | Manufacturing | 2020 |
| Renex Group Ltd | Financial services | 2021 |
| RENTAL4 Ltd | Administrative & support | 2021 |
| Research My Past Ltd | Information & communication | 2020 |
| Residential Accommodation Management Ltd | Real estate | 2025 |
| Resource Direct (UK) Limited | Wholesale & retail | 2005 |
| Resurgam Health Ltd | Financial services | 2018 |
| Reteuro Limited | Wholesale & retail | 2021 |
| Retireinvest Limited | Financial services | 2015 |
| Revene Property Company Limited | Administrative & support | 2000 |
| Revive Construction Group Limited | Professional & scientific | 2018 |
| Revs Community CIC | Wholesale & retail | 2022 |
| Rfps Grantham Ltd | Manufacturing | 2022 |
| RGO Rigging Ltd | Arts & recreation | 2021 |
| RGT Homes Limited | Construction | 2017 |
| RH Building & Restoration Limited | Construction | 2014 |
| Rheoform Engineering Ltd | Manufacturing | 2024 |
| Richard Epton (Farms) | Agriculture & fishing | 1961 |
| Richard James Green Limited | Financial services | 2012 |
| Richard Malley Floordesigns Ltd | Households | 2022 |
| Richard West Building Company Limited | Construction | 2014 |
| Richards & Richards Consultancy Limited | Information & communication | 2018 |
| Richmond Clicks Ltd | Extraterritorial | 2025 |
| Richmond Plant Hire Limited | Administrative & support | 2007 |
| Richmond Services Ltd | Transport & logistics | 2023 |
| Richmond Van Hire Limited | Administrative & support | 2010 |
| Richwood Automation Limited | Information & communication | 2015 |
| Rick Streeter Limited | Wholesale & retail | 2002 |
| Rickard Property Ltd | Households | 2021 |
| Ridgesome Limited | Real estate | 1997 |
| Right Move Homes Ltd | Real estate | 2017 |
| Rimington Heaton LLP | | 2012 |
| Ringrose Wharton LLP | | 2018 |
| Ringswell Park Ltd | Administrative & support | 2022 |
| Risa (UK) Limited | Transport & logistics | 2001 |
| Rise & Shine Milk Limited | Wholesale & retail | 2020 |
| Riseley Homes Ltd | Construction | 2019 |
| Rising Sun 22 Ltd | Hospitality | 2023 |
| Risk Reduced Ltd | Financial services | 2022 |
| Rivs Cafe Ltd | Hospitality | 2026 |
| Riya SRI Enterprise Ltd | Wholesale & retail | 2019 |
| RJD Property Investments Ltd | Real estate | 2025 |
| RJL Building & Plant Hire Limited | Construction | 2023 |
| RJM Motor Repairs Limited | Wholesale & retail | 2018 |
| RKM Hospitality Limited | Hospitality | 2024 |
| RM Business Consulting Ltd | Administrative & support | 2007 |
| Rmdistributions Ltd | Wholesale & retail | 2026 |
| Rmds Property Limited | Real estate | 2025 |
| RMJ Fine Foods Ltd | Hospitality | 2019 |
| RMJ News Ltd | Wholesale & retail | 2021 |
| RMJ Trading Ltd | Wholesale & retail | 2018 |
| RN Company Retail Limited | Wholesale & retail | 2022 |
| Roadpulse Transport Limited | Transport & logistics | 2016 |
| Robin and Twine Limited | Wholesale & retail | 2026 |