| Secure Lifting Limited | Construction | 2025 |
| Secure Plumbing Ltd | Construction | 2025 |
| Secure Shredding Limited | Water & waste | 2025 |
| Secure Source Estates Ltd | Households | 2025 |
| Securemerge Residents Management Limited | Households | 1986 |
| Security Telecom Link Ltd | Transport & logistics | 2014 |
| Sedam Communications Limited | Extraterritorial | 1997 |
| SEE Round Corners Ltd | Administrative & support | 2025 |
| Seeco (UK) Limited | Manufacturing | 1985 |
| SEEM2CLEAN Ltd | Administrative & support | 2025 |
| Seen IT on TV Limited | Professional & scientific | 2015 |
| Seer Consult Ltd | Professional & scientific | 2023 |
| SEF Enterprises Limited | Information & communication | 2011 |
| SEF UK Holdings Ltd | Financial services | 2019 |
| Sefra Electromagnetics Limited | Professional & scientific | 2024 |
| SEG Building & Developments Ltd | Construction | 2020 |
| SEG Traders Ltd. | Construction | 2015 |
| SEH Renovations Ltd | Construction | 2022 |
| Seju & Co Limited | Wholesale & retail | 2026 |
| Sekhon Home Improvments Ltd | Construction | 2019 |
| Selah Estates Ltd | Real estate | 2024 |
| Selborne Meadows Limited | Administrative & support | 2018 |
| Selea Ltd | Hospitality | 2025 |
| Select Office Support Ltd | Professional & scientific | 2023 |
| Select Sports Management Limited | Arts & recreation | 2017 |
| Select Travel Group Limited | Administrative & support | 2020 |
| Select Travel Holidays Limited | Administrative & support | 2006 |
| Select Your Motor Ltd | Wholesale & retail | 2025 |
| Selectflow Consulting Limited | Information & communication | 2025 |
| Selectial Ltd | Administrative & support | 2017 |
| Seleniet Limited | Wholesale & retail | 2021 |
| Self Funding Ltd | Real estate | 2010 |
| Self Investment Limited | Professional & scientific | 2003 |
| Selgevesi Limited | Professional & scientific | 2023 |
| Sellan Properties Limited | Real estate | 2020 |
| Sellcar Limited | Extraterritorial | 2006 |
| Sellyourcartheeasyway Ltd | Wholesale & retail | 2023 |
| Sembhi Property Ltd | Real estate | 2026 |
| Senate Electrical Ltd | Construction | 2021 |
| Sendu Holdings Ltd | Financial services | 2026 |
| Senen Ltd | Information & communication | 2025 |
| Senior Serene Limited | Arts & recreation | 2023 |
| Seniorshield Systems Limited | Manufacturing | 2025 |
| Sensations LAB Ltd | Administrative & support | 2017 |
| Sense Housing Group CIC | Hospitality | 2022 |
| Senua Limited | Professional & scientific | 2025 |
| Sequel Coaching Ltd | Professional & scientific | 2026 |
| SER & Beri Limited | Wholesale & retail | 2020 |
| Serenade Home Improvements Ltd | Construction | 2021 |
| Serengeti Systems Limited | Information & communication | 1998 |
| Serenity Care East Anglia Limited | Health & social care | 2010 |
| Serenity Carenest Solutions Limited | Administrative & support | 2025 |
| Serenity Flame Limited | Manufacturing | 2024 |
| Serenity Funerals Service Ltd | Other services | 2024 |
| Serenity Hair and Beauty Day Spa Ltd | Other services | 2026 |
| Serenity Spa & Body Ltd | Other services | 2025 |
| Serenitysparkles Ltd | Wholesale & retail | 2024 |
| Sergiu Dima Ltd | Transport & logistics | 2019 |
| Serious World C.I.C. | Public administration | 2024 |
| Serra BAH Ltd | Other services | 2012 |
| Serra Montagna Limited | Wholesale & retail | 2019 |
| Service Contract Consultancy Limited | Professional & scientific | 2012 |
| Service Express Emea Limited | Financial services | 2021 |
| Service Flow Apps Limited | Information & communication | 2026 |
| Service ZEN Ltd | Professional & scientific | 2026 |
| Servicescheck. COM Limited | Hospitality | 2001 |
| Servitech Consulting Ltd | Information & communication | 2002 |
| Servitech International Limited | Manufacturing | 2000 |
| Setech Technical Ltd | Construction | 2026 |
| Seven Eleven Store Ltd | Wholesale & retail | 2025 |
| Seven Pines Property Limited | Real estate | 2018 |
| Seven SQ Limited | Professional & scientific | 2019 |
| Seven Squirrel Ltd | Professional & scientific | 2025 |
| Seventy Seven Properties Limited | Financial services | 2018 |
| Seylanika Ltd | Transport & logistics | 2016 |
| SF Brokers Ltd | Financial services | 2026 |
| SF Property Experts Ltd | Hospitality | 2025 |
| SF2 Bedford Limited | Arts & recreation | 2019 |
| Sfaesthetics - Forever YOU Ltd | Other services | 2022 |
| Sfenn Rigging Ltd | Construction | 2019 |
| SFK Construction Ltd | Construction | 2016 |
| SFS Performance Engineering Limited | Extraterritorial | 2011 |
| SG Nurseries Limited | Education | 2023 |
| SG Rendering Ltd | Construction | 2026 |
| SH Automotive Bedford Ltd | Wholesale & retail | 2024 |
| SH Canine Services Limited | Professional & scientific | 2024 |
| Shaar Bridge Solicitors Ltd | Professional & scientific | 2019 |
| Shadowplay Limited | Professional & scientific | 2023 |
| Shah JAN Ltd | Financial services | 2023 |
| Shah Sustainability Solutions Limited | Professional & scientific | 2025 |
| Shahbano Ltd | Wholesale & retail | 2023 |
| Shahchisti Ltd | Transport & logistics | 2023 |
| Shahs Property Ltd | Real estate | 2025 |
| Shak's Plumbing & Heating Ltd | Construction | 2026 |
| Shaka Limited | Manufacturing | 2024 |
| Shake Box Desserts Ltd | Hospitality | 2016 |
| Shakespeare Clinic LLP | | 2019 |
| Shakey B’S Ltd | Hospitality | 2025 |
| Shaktea Ltd | Manufacturing | 2025 |
| Shaldon Court (Bedford) RTM Company Limited | Households | 2011 |