| RR Recruitment Solutions Ltd | Administrative & support | 2025 |
| RSA Production House Limited | Information & communication | 2024 |
| RSC Pipelines Limited | Construction | 1992 |
| RTJ Consulting Ltd | Information & communication | 2024 |
| RTW Direct Limited | Wholesale & retail | 2015 |
| Ru's Brow & Beauty Studio Limited | Other services | 2023 |
| RU2 Property Ltd | Real estate | 2026 |
| Rubit Ltd | Information & communication | 2021 |
| Ruby Coopers Ltd | Hospitality | 2025 |
| Rumours Styling Limited | Other services | 2013 |
| Rural Design & Build Ltd | Construction | 2016 |
| Rush Sports Limited | Arts & recreation | 2025 |
| Rushmer Holdings Ltd | Financial services | 2025 |
| Russell Eacott Associates Limited | Manufacturing | 2004 |
| Russell Sant Limited | Wholesale & retail | 2025 |
| Ruston's Engineering Company Limited | Manufacturing | 1955 |
| Ryan Research Limited | Professional & scientific | 1995 |
| Ryehill Bungalows Management Company Limited | Professional & scientific | 2012 |
| S & G Shopfitters Ltd | Construction | 2011 |
| S & J Design Consultants Ltd | Administrative & support | 2003 |
| S & J Design Property Services Limited | Real estate | 2022 |
| S & N Mobile Ltd | Professional & scientific | 2025 |
| S B Home Renovations Limited | Construction | 2022 |
| S G Acoustics Limited | Manufacturing | 1996 |
| S L Couch Ltd | Professional & scientific | 2023 |
| S M W Legal Services Ltd | Professional & scientific | 2013 |
| S P S Pumps & Engineering Limited | Professional & scientific | 2005 |
| S R Drylining Limited | Construction | 2002 |
| S R P Accounting Services Limited | Professional & scientific | 2018 |
| S T Garage Ltd | Wholesale & retail | 2020 |
| S X Wholesale Ltd | Wholesale & retail | 2026 |
| S&A Insights Ltd | Professional & scientific | 2025 |
| S.G.Hamilton Consulting Ltd | Professional & scientific | 2016 |
| S.M.Burton Limited | Agriculture & fishing | 1961 |
| Saamira Trans Ltd | Transport & logistics | 2025 |
| Sabina Cleaning Huntingdon Ltd | Administrative & support | 2022 |
| Saddle Spice Ltd | Hospitality | 2025 |
| Saddle Wizards Limited | Wholesale & retail | 2023 |
| Safe Cambridgeshire Transport Ltd | Transport & logistics | 2025 |
| Safe Start Supported Living Limited | Administrative & support | 2025 |
| Safehaven Lettings & Management Limited | Real estate | 2026 |
| Safemoves Removals Ltd | Transport & logistics | 2009 |
| Safer Beginnings Limited | Professional & scientific | 2021 |
| Safety Products Direct Limited | Wholesale & retail | 2011 |
| Safety Sense Ltd | Professional & scientific | 2025 |
| Safetyworks & Solutions Limited | Construction | 2001 |
| Safeworks Europe Ltd | Administrative & support | 2021 |
| Safeworks Limited | Extraterritorial | 1999 |
| Sage Cambridge Ltd | Professional & scientific | 2010 |
| Sail Bidco Limited | Financial services | 2025 |
| Sail Midco 1 Limited | Financial services | 2025 |
| Sail Midco 2 Limited | Financial services | 2025 |
| Sail Topco Limited | Financial services | 2025 |
| Salesatwork Limited | Information & communication | 2013 |
| Salice UK Limited | Wholesale & retail | 1985 |
| Salix Holdings Ltd | Financial services | 2022 |
| Salo Toleno Limited | Real estate | 2023 |
| Salon 42 (Sawtry) Limited | Other services | 2014 |
| Saloschin Limited | Mining & quarrying | 2007 |
| Salt and Sand Limited | Hospitality | 2022 |
| Salt Sales INT Limited | Professional & scientific | 1995 |
| SALUS365 Ltd | Education | 2021 |
| SAM Auto and Part Ltd | Transport & logistics | 2024 |
| SAM Lane Engineering Limited | Professional & scientific | 2025 |
| SAM Private Hire Huntingdon Ltd | Transport & logistics | 2019 |
| Sam,S East Ckeaning Limited | Administrative & support | 2023 |
| SAN Luca Tattoo Lounge (Cambs) Ltd | Other services | 2022 |
| SAN Luca Tattoo Lounge Ltd | Other services | 2018 |
| Sand Transport Ltd | Transport & logistics | 2022 |
| Sandpoint Investments Limited | Real estate | 2026 |
| Sandy's Cars Ltd | Wholesale & retail | 2018 |
| Sani Hand Car Wash Ltd | Other services | 2018 |
| Saniexcellence Ltd | Construction | 2024 |
| Sapphire Sparkle Cleaning Limited | Administrative & support | 2022 |
| Sargent Groznov Corporation Limited | Administrative & support | 2023 |
| Satchwell Logistics Limited | Transport & logistics | 2017 |
| Savannah Energy Global Ltd | Wholesale & retail | 2024 |
| Sawtry Barbers Ltd | Other services | 2025 |
| Sawtry Marquees Limited | Other services | 2007 |
| SB Builders Limited | Construction | 2012 |
| SB Logistic Services Ltd | Transport & logistics | 2016 |
| Sbtl Property Ltd | Real estate | 2021 |
| Scafell Media Ltd | Information & communication | 2024 |
| Scanis Limited | Professional & scientific | 2025 |
| Scenic Estates Limited | Hospitality | 1992 |
| Scenic Skate Shop Ltd | Wholesale & retail | 2025 |
| Schahu Ltd | Administrative & support | 2021 |
| Schofield Family Properties Ltd | Real estate | 2020 |
| Scoped Ltd | Information & communication | 2026 |
| Scott Engineering Consultants Ltd | Professional & scientific | 2012 |
| Scott Joseph Media Limited | Arts & recreation | 2015 |
| Scott-Petrie Property Investments Limited | Real estate | 2025 |
| Scottie Products Ltd | Manufacturing | 2015 |
| Scribo Puzzles Publishing Ltd | Information & communication | 2021 |
| Scripture Union Partners in Action UK Ltd | Other services | 2023 |
| Scrumseeker Consulting Ltd | Information & communication | 2017 |
| SD Scientific Solutions Limited | Professional & scientific | 2024 |
| SDE Properties Ltd | Real estate | 2023 |
| SE 100-106 Limited | Real estate | 2025 |
| Seachill Limited | Extraterritorial | 1997 |