| Rowse Consulting Limited | Professional & scientific | 2021 |
| Roycraft Property Management Ltd | Real estate | 2015 |
| Rozar Limited | Information & communication | 2010 |
| RP Cars Panel Repair Ltd | Wholesale & retail | 2025 |
| RPS Fabrications Ltd | Manufacturing | 2024 |
| RR Rosiane Romao Best Sellers Limited | Wholesale & retail | 2023 |
| RRR Pavement Solutions (R3) Ltd | Construction | 2020 |
| RS Commercial Trailer Services Ltd | Manufacturing | 2020 |
| RT Automotive Services Ltd | Wholesale & retail | 2024 |
| RT Samonte Limited | Professional & scientific | 2023 |
| RU Tang Ltd | Wholesale & retail | 2026 |
| Rubicon Nuclear Services Ltd | Professional & scientific | 2012 |
| Ruby Consulting Limited | Professional & scientific | 2025 |
| Rubywillows Limited | Financial services | 2019 |
| Ruee Holdings Ltd | Wholesale & retail | 2023 |
| Ruffe Industries Limited | Professional & scientific | 2023 |
| Rumronald Limited | Wholesale & retail | 2023 |
| Rushmere Engineering Ltd | Manufacturing | 2021 |
| Rushmere Nurseries Limited | Agriculture & fishing | 1955 |
| Russet Estates Limited | Real estate | 2024 |
| Rutland Court Management Company Limited | Households | 1986 |
| RVO Consulting Ltd | Information & communication | 2024 |
| RW Car Body Repairs Ltd | Wholesale & retail | 2023 |
| Rwootton Ltd | Information & communication | 2025 |
| S & J Mccann Carpentry and Building Services Limited | Construction | 2023 |
| S & S Builders Limited | Extraterritorial | 2005 |
| S & S Homes Limited | Real estate | 2017 |
| S a FOX Ltd | Information & communication | 2015 |
| S B Mills Limited | Construction | 2003 |
| S F Systems Ltd | Information & communication | 2017 |
| S H Tyres Limited | Wholesale & retail | 2006 |
| S Turner Brands Limited | Wholesale & retail | 2020 |
| S Z Z Property Management Limited | Other services | 2009 |
| S&K Days Ltd | Education | 2023 |
| S-Dice Limited | Information & communication | 2020 |
| S.M.J. Consultancy Limited | Information & communication | 1998 |
| S.T.Jones Consultancy Ltd | Professional & scientific | 2026 |
| Sabona Soul Shack Ltd | Hospitality | 2026 |
| Saeba Technology Ltd | Information & communication | 2017 |
| Safeagile Limited | Information & communication | 2018 |
| Safer Living & Care Limited | Health & social care | 2026 |
| Safety Surveys Ltd | Professional & scientific | 2019 |
| Safeway Inspections Ltd | Other services | 2025 |
| Safran Electrical & Power UK Ltd | Manufacturing | 2012 |
| Sagaris Development Limited | Other services | 2017 |
| Sage IT Limited | Information & communication | 2022 |
| Saint John Jacob | Other services | 2014 |
| Sakthi and Nirmala Property Rentals Limited | Real estate | 2024 |
| Sakthi Cash & Carry Trading Ltd | Wholesale & retail | 2025 |
| Salaam IT Engineering Ltd | Information & communication | 2026 |
| Salesbiz Services Limited | Professional & scientific | 2018 |
| Salesbizplus Limited | Professional & scientific | 2021 |
| Samoa Apparel Ltd | Wholesale & retail | 2021 |
| Sanbha Solutions Limited | Information & communication | 2017 |
| Sand Hills (Leighton Buzzard) Residents Association Limited | Households | 2003 |
| Sandeep Consulting Limited | Information & communication | 2008 |
| Sandhersons Newsagents Limited | Wholesale & retail | 2011 |
| Sandhersons Property Limited | Real estate | 2011 |
| Sandy Bay Solutions Limited | Professional & scientific | 2017 |
| Sanyangorec Company Limited | Health & social care | 2018 |
| Saoe Ltd | Professional & scientific | 2026 |
| Sapphire Glass Ltd | Wholesale & retail | 2014 |
| Sarah James Woodwind Limited | Arts & recreation | 2025 |
| Sardo Trading Limited | Professional & scientific | 2010 |
| Sarisson Solutions Limited | Professional & scientific | 2020 |
| Satt Consultancy Limited | Administrative & support | 2010 |
| Saturnvr Ltd | Education | 2026 |
| Savage Controls Ltd | Construction | 2018 |
| SAVINA16DS Transport Ltd | Transport & logistics | 2023 |
| SB Stagehand Ltd | Arts & recreation | 2020 |
| SBA Coven Ltd | Other services | 2026 |
| SBA Tax & Accountancy Ltd | Professional & scientific | 2013 |
| Sbitnoa Ltd | Wholesale & retail | 2024 |
| SC Screeding Ltd | Manufacturing | 2020 |
| School Viewer Ltd | Professional & scientific | 2020 |
| Schrades Wholesale Ltd | Wholesale & retail | 2022 |
| Scissor and Sword Prestige Worldwide Ltd | Manufacturing | 2022 |
| Scoop a Bargain Ltd | Wholesale & retail | 2016 |
| Scratched Glass Services Limited | Construction | 2016 |
| Scribed Developments Ltd | Construction | 2026 |
| SCS Environmental Limited | Professional & scientific | 2015 |
| Sculptors Hair Company Limited | Other services | 2009 |
| SD Carpentry (Leighton Buzzard) Ltd | Construction | 2016 |
| SD Carpentry and Construction Limited | Construction | 2025 |
| SDC Electrics Ltd | Construction | 2025 |
| SE7EN Communications Limited | Professional & scientific | 2017 |
| Sea Unicorn Promotions Ltd | Arts & recreation | 2025 |
| Sead Incorporated Ltd | Professional & scientific | 2022 |
| Seagrass Limited | Administrative & support | 1998 |
| Sears Contract Management Ltd | Construction | 2019 |
| Sears Storage Ltd | Transport & logistics | 2021 |
| Seasoned Carpentry & Joinery Ltd | Construction | 2019 |
| Seastar Systems Ltd | Professional & scientific | 2024 |
| Sebastian Stroilescu Ltd | Transport & logistics | 2018 |
| SEC Coretech Ltd | Other services | 2025 |
| Secure Driven Solutions Ltd | Information & communication | 2023 |
| Seemple Limited | Information & communication | 2012 |
| Sega Consultancy Ltd | Information & communication | 2022 |
| Segue Connections Ltd | Professional & scientific | 2016 |
| Segullah Solutions Limited | Administrative & support | 2016 |