| Serenity Nails & Beauty (Northampton) Limited | Professional & scientific | 2013 |
| Sergio and Robi Pizzeria Ltd | Hospitality | 2021 |
| Series Athlete Limited | Professional & scientific | 2023 |
| Serj Trans Ltd | Transport & logistics | 2025 |
| Serk Services Ltd | Professional & scientific | 2025 |
| Serpent Designs Ltd | Manufacturing | 2015 |
| Serval Holdings Ltd | Financial services | 2021 |
| Serve X Solutions Limited | Transport & logistics | 2026 |
| Service Express Limited | Wholesale & retail | 2011 |
| Service MOT Repairs Limited | Wholesale & retail | 2012 |
| Services&Co Ltd | Other services | 2017 |
| SET for Sun Ltd | Administrative & support | 2025 |
| Setified Ltd | Wholesale & retail | 2016 |
| Seun Fagbohun Consulting Ltd | Information & communication | 2026 |
| Seven Seconds Media Ltd | Information & communication | 2024 |
| Seven Spirit Limited | Hospitality | 2012 |
| Seven Tees Limited | Financial services | 2018 |
| Seven Thirty Events Co Ltd | Arts & recreation | 2021 |
| Sevenfold Professionals Limited | Health & social care | 2013 |
| Sevens Events Management Limited | Transport & logistics | 2023 |
| Seventh Consulting Ltd | Administrative & support | 2024 |
| Seventree Ltd | Financial services | 2021 |
| Seventy Seven Autos Limited | Wholesale & retail | 2016 |
| Seventy Seven Music Limited | Arts & recreation | 2017 |
| Seventy Seven Productions Limited | Arts & recreation | 2012 |
| Seventy Two Wealth Ltd | Professional & scientific | 2012 |
| Severin Transport Ltd | Wholesale & retail | 2020 |
| Severn Property Consultancy Limited | Real estate | 2012 |
| Sevimli Ltd | Hospitality | 2021 |
| Sew-Quick Limited | Wholesale & retail | 2018 |
| Sewing for Sanity CIC | Arts & recreation | 2026 |
| Seyi Developments Limited | Real estate | 2024 |
| Sezoni Limited | Wholesale & retail | 2018 |
| SF Cleanerz Ltd | Administrative & support | 2024 |
| SF Health Services Limited | Health & social care | 2024 |
| SF Installations Limited | Construction | 2003 |
| SF Management & Maintenance Ltd | Construction | 2021 |
| Sfarma Stone Ltd | Construction | 2022 |
| SFC Property Services Limited | Real estate | 2016 |
| SFR UK Team Ltd | Wholesale & retail | 2012 |
| SFS Transport Ltd | Wholesale & retail | 2018 |
| SFV Services Limited | Information & communication | 2023 |
| SG Carp FIC Limited | Financial services | 2023 |
| SG Carp LLP | | 2023 |
| SG Resourcing Limited | Other services | 2020 |
| Sgawholesale Limited | Wholesale & retail | 2020 |
| SGB Landscapes Ltd | Administrative & support | 2025 |
| SGK Collective Ltd | Professional & scientific | 2026 |
| SGK Interiors Ltd | Construction | 2015 |
| SGL Print and Design Limited | Manufacturing | 2002 |
| SGR Marketing Limited | Professional & scientific | 2015 |
| SH Carpentry Limited | Construction | 2016 |
| SH Consulting & Marketing Limited | Information & communication | 2012 |
| Shaakh Limited | Information & communication | 2022 |
| Shackleton Halls 2 Limited | Real estate | 2022 |
| Shade Water Gardens Limited | Construction | 2025 |
| Shaded Hair Extensions Ltd | Wholesale & retail | 2025 |
| Shades of Sun Ltd | Other services | 2018 |
| Shadow International Ltd | Administrative & support | 2021 |
| Shadow Shirts Ltd | Wholesale & retail | 2016 |
| Shadowcat Creative Limited | Professional & scientific | 2020 |
| Shafi Malik Enterprise Limited | Hospitality | 2016 |
| Shafique and Sons Investments Ltd | Real estate | 2020 |
| Shah Indian Ltd | Hospitality | 2020 |
| Shah Remote Services Ltd | Administrative & support | 2024 |
| Shah Rentals Limited | Real estate | 2021 |
| Shahab Fast Food Ltd | Hospitality | 2022 |
| Shahadah Holdings Ltd | Health & social care | 2023 |
| SHAHGEE110 Services Ltd | Transport & logistics | 2026 |
| Shaho Ltd | Wholesale & retail | 2025 |
| Shaho’Oto Ltd | Wholesale & retail | 2025 |
| Shahter Ltd | Transport & logistics | 2019 |
| Shahzaib Restaurant & Banqueting Suite Ltd | Hospitality | 2026 |
| Shaid Family Property Ltd | Real estate | 2023 |
| Shaikly Investment Holdings Limited | Financial services | 2026 |
| Shaikly Racing Ltd | Arts & recreation | 2025 |
| Shaivait Ltd | Information & communication | 2023 |
| Shakespeare 51-53 Ltd | Administrative & support | 2020 |
| Shaks Grill House Limited | Hospitality | 2024 |
| Shakti Tantra Limited | Other services | 2015 |
| Shala Neurodevelopmental Services Limited | Health & social care | 2025 |
| Shalom JJJ Solutions Ltd | Information & communication | 2015 |
| Shalom Rentals Limited | Real estate | 2021 |
| Sham LAL Aggarwal Ltd | Professional & scientific | 2016 |
| Shamar Live in Care Ltd | Health & social care | 2025 |
| Shams Ophthalmics Limited | Health & social care | 2023 |
| Shamsedge Ltd | Wholesale & retail | 2025 |
| Shamsu Uddin Limited | Transport & logistics | 2025 |
| Shanahan Property Ltd | Real estate | 2025 |
| Shanaya Jaan Property Investment Ltd | Real estate | 2026 |
| Shanlocstudio Ltd | Other services | 2026 |
| Shanthi Estates Limited | Real estate | 2021 |
| Shared Churches (Northampton) Limited | Other services | 1972 |
| Sharma & Bros Ltd | Financial services | 2015 |
| Sharman Sall Consultancy Limited | Real estate | 2019 |
| Sharon & Daughters Ltd | Construction | 2026 |
| Sharp Architectural Services Limited | Professional & scientific | 2020 |
| Sharp Contracting Limited | Construction | 2014 |
| Sharp EYE Security Limited | Administrative & support | 2008 |
| Sharp Healthcare Solutions Limited | Health & social care | 2014 |