| Rumbles Weldon Ltd | Hospitality | 2025 |
| Rushinga Ltd | Professional & scientific | 2024 |
| Rusnac ID Ltd | Wholesale & retail | 2024 |
| Rusty’S Truck Interiors Limited | Manufacturing | 2020 |
| Rusu LDN Limited | Professional & scientific | 2016 |
| Rutland Commercial Management Ltd | Professional & scientific | 2014 |
| Rutland Cookery School Limited | Hospitality | 2025 |
| Rutland Homes Limited | Construction | 2000 |
| Rutland Range Co. Ltd | Wholesale & retail | 2023 |
| RWA Engineering Limited | Professional & scientific | 2023 |
| RWG Engineering Services Ltd | Professional & scientific | 2026 |
| RWR ENG Ltd | Manufacturing | 2020 |
| RXT Ltd | Construction | 2022 |
| RYC Logistic Ltd | Construction | 2024 |
| S & B Care Services Ltd | Health & social care | 2013 |
| S & C Green Ltd | Transport & logistics | 2016 |
| S & T Motors Corby Limited | Wholesale & retail | 2024 |
| S L Services (Southern) Ltd | Administrative & support | 2009 |
| S M Painting Ltd | Construction | 2018 |
| S Wiseman Sports Limited | Arts & recreation | 2013 |
| S&A Corby Hotel Limited | Hospitality | 2015 |
| S&A Corby Management Limited | Hospitality | 2015 |
| S.Church Plumbing & Heating Limited | Construction | 2002 |
| S.Good Transport Limited | Transport & logistics | 2014 |
| S.K. Cars (Corby) Limited | Wholesale & retail | 2013 |
| S.N.B Cleaning Services Limited | Other services | 2025 |
| S2 Sales Support Limited | Wholesale & retail | 2021 |
| S4S Special Projects Ltd | Administrative & support | 2023 |
| S58 Consulting Limited | Administrative & support | 2021 |
| SA Careline Ltd | Health & social care | 2022 |
| Safe FIX Reinforcement Limited | Construction | 2018 |
| Safe Property Solutions Ltd | Real estate | 2013 |
| Safe Staff UK Limited | Administrative & support | 2024 |
| Safenet Limited | Professional & scientific | 1996 |
| Safety Group Global Ltd | Administrative & support | 2025 |
| Safir Petru SRL Ltd | Wholesale & retail | 2024 |
| Saga’S Beaty Room Ltd | Other services | 2024 |
| Sahin Deals Ltd | Wholesale & retail | 2026 |
| Saini & SON Ltd | Transport & logistics | 2020 |
| Sajinel Ltd | Construction | 2019 |
| Salku Limited | Administrative & support | 2008 |
| Sall Construction Ltd | Construction | 2025 |
| Salonista Ltd | Other services | 2015 |
| Salvatex Holdings Limited | Professional & scientific | 1994 |
| Salvatex Propco Limited | Real estate | 2020 |
| Salvatex Trading Limited | Wholesale & retail | 2016 |
| SAM Rada Recruitment Limited | Administrative & support | 2022 |
| Sambeth Limited | Professional & scientific | 2013 |
| Samir Miah Investments Limited | Real estate | 2022 |
| Samm Engineering Limited | Manufacturing | 2011 |
| Sammy's Super Maids Ltd | Administrative & support | 2020 |
| Sanbert Consultancy Ltd | Professional & scientific | 2022 |
| Sanyman Trans Limited | Transport & logistics | 2019 |
| Sas-Trans Ltd | Transport & logistics | 2020 |
| Sasl Limited | Health & social care | 2018 |
| Sauna'N'Soak Ltd | Health & social care | 2025 |
| Save Barton Seagrave’S Spinneys Ltd | Public administration | 2025 |
| Save Couriers Ltd | Wholesale & retail | 2024 |
| Savplumb Elite Ltd | Construction | 2025 |
| SAW Design & Build Ltd | Construction | 2025 |
| Sawford Engineering Limited | Administrative & support | 2009 |
| Sawiak Commercial Finance Limited | Financial services | 2020 |
| Sayclean Services Ltd | Administrative & support | 2023 |
| Sayell PAY Ltd | Wholesale & retail | 2024 |
| Scan Alarms (Corby) Limited | Administrative & support | 2018 |
| Scene Salon Ltd | Other services | 2021 |
| Scent Bakers LP | | 2022 |
| Scisto Ltd | Health & social care | 2026 |
| Scope Services Group Ltd | Construction | 2020 |
| Scott Anglia Homes Limited | Construction | 1997 |
| Scott Collective Ltd | Professional & scientific | 2025 |
| Scott Hall Repairs Limited | Wholesale & retail | 2009 |
| Scrub Squad Solutions Ltd | Administrative & support | 2025 |
| Scutt Beaumont Solicitors Ltd | Professional & scientific | 2010 |
| Sean M Electrical Ltd | Construction | 2018 |
| Seanarico Limited | Health & social care | 2021 |
| Searson's Building Services Limited | Administrative & support | 2013 |
| Seatons Law Holdings Limited | Financial services | 2023 |
| Seatons Law Limited | Professional & scientific | 2013 |
| SEB Motors Automotive Ltd | Wholesale & retail | 2026 |
| Seba Prest Services Limited | Transport & logistics | 2018 |
| Sebastian Sowinski Ltd | Wholesale & retail | 2016 |
| Sebtudor Limited | Transport & logistics | 2018 |
| Sebway Limited | Transport & logistics | 2026 |
| Secure First Solutions Ltd | Information & communication | 2010 |
| Security Dog Handling Services Limited | Administrative & support | 2001 |
| SEE Limited | Financial services | 2016 |
| Seedlings Property Limited | Professional & scientific | 2014 |
| Seglex 2000 Ltd | Professional & scientific | 2019 |
| Sego Group Ltd | Health & social care | 2025 |
| SEJ Enterprises Limited | Hospitality | 2018 |
| Select Beauty Academy Limited | Wholesale & retail | 2026 |
| Selir Services Ltd | Transport & logistics | 2021 |
| SELLYOURCAR2ADAM.COM Limited | Wholesale & retail | 2011 |
| Selsia Vehicle Accident Centres Limited | Wholesale & retail | 2009 |
| SEP Agri Limited | Financial services | 2019 |
| SEP Agricultural Management Ltd | Professional & scientific | 2020 |
| SEP International Group Limited | Financial services | 2019 |
| SEP Transport Ltd | Transport & logistics | 2026 |
| Serenity Beauty Priors Ltd | Other services | 2023 |