| Sequence Services Limited | Information & communication | 2020 |
| Sequences Management Limited | Professional & scientific | 2018 |
| Sequin Designs Ltd | Manufacturing | 2004 |
| Sequoia Capital Holdings Ltd | Real estate | 2026 |
| Sequoia Healthcare Services Limited | Wholesale & retail | 2020 |
| Sequoia Property Group Limited | Real estate | 2022 |
| Sequoia Realty Limited | Real estate | 2021 |
| Seraj Properties Ltd | Hospitality | 2022 |
| Seraphim Consulting Ltd | Professional & scientific | 2025 |
| Serbian Chetniks Leicester Club Ltd | Hospitality | 2017 |
| Sercova.Uk Limited | Information & communication | 2026 |
| Seren Pathways CIC | Health & social care | 2026 |
| Serena's Patisserie Ltd | Manufacturing | 2026 |
| Serendipity Artists Movement Limited | Arts & recreation | 2010 |
| Serendipity Home and Healing Limited | Health & social care | 2023 |
| Serene 360 Limited | Wholesale & retail | 2020 |
| Serene Beauty Studio Ltd | Other services | 2026 |
| Serene Embrace Limited | Wholesale & retail | 2025 |
| Serene Health Innovations Ltd | Health & social care | 2025 |
| Serene Holidays Ltd | Administrative & support | 2020 |
| Serene Sparks Ltd | Health & social care | 2024 |
| Sereneflo Limited | Construction | 2023 |
| Serenity Inmind Housing CIC | Construction | 2022 |
| Serenity Inmind Limited | Health & social care | 2014 |
| Serenity Inmind Properties Limited | Hospitality | 2017 |
| Serenity Lakes Lodge 16 Limited | Professional & scientific | 2025 |
| Serenity Lakes Lodge 17 Limited | Professional & scientific | 2025 |
| Serenity Lakes Lodge 18 Limited | Professional & scientific | 2025 |
| Serenity Path Ltd | Health & social care | 2025 |
| Serenity Relaxation Ltd | Real estate | 2024 |
| Serenity Therapy Ltd | Other services | 2020 |
| Sereniya Ltd | Wholesale & retail | 2026 |
| Serens Seasons Ltd | Health & social care | 2025 |
| Serenta Care UK Limited | Administrative & support | 2025 |
| Serenta Recruitment Ltd | Administrative & support | 2025 |
| Sergiu Construction Ltd | Construction | 2025 |
| Serious Driving Company MC Limited | Other services | 2017 |
| Serious Serious Company Ltd | Professional & scientific | 2024 |
| Serjeants LLP | | 2012 |
| Sertas Limited | Information & communication | 2003 |
| Serve (Birmingham) Ltd | Arts & recreation | 2018 |
| Serviam Cottage Ltd | Health & social care | 2024 |
| Serviam Group Ltd | Financial services | 2024 |
| Serviam House Ltd | Health & social care | 2024 |
| Service 2 Ltd | Transport & logistics | 2021 |
| Service Design AC Ltd | Professional & scientific | 2025 |
| Service Solutionz Ltd | Information & communication | 2024 |
| Services Base Ltd | Real estate | 2025 |
| Servin-Tech Limited | Financial services | 2020 |
| Servisauras Ltd | Information & communication | 2026 |
| SES Medical Writing Ltd | Professional & scientific | 2011 |
| Seshu Constructions Ltd | Construction | 2026 |
| Sesysy Limited | Construction | 2024 |
| SET2CLEAR Ltd | Wholesale & retail | 2021 |
| Seth's Estate Agents Limited | Real estate | 1999 |
| Sethico Holdings Limited | Financial services | 2020 |
| Sethwara Ltd | Real estate | 2021 |
| Sett Landscapes & Property Ltd | Construction | 2020 |
| Settiq Labs Ltd | Information & communication | 2026 |
| Settled Mortgages Limited | Financial services | 2021 |
| Setu Marketing Limited | Professional & scientific | 2026 |
| SEV & Savour Ltd | Manufacturing | 2025 |
| SEV2000 Ltd | Construction | 2018 |
| SEV7ENCLOUDS Ltd | Wholesale & retail | 2025 |
| Seva Circle CIC | Health & social care | 2025 |
| Seva Home Care Limited | Health & social care | 2025 |
| Seva Karma Limited | Real estate | 2025 |
| Sevar Barbers Ltd | Other services | 2025 |
| Sevaserves Ltd | Hospitality | 2025 |
| Seven 778 SIX Ltd | Real estate | 2025 |
| Seven Blues International Ltd | Manufacturing | 2025 |
| Seven Caterers Limited | Hospitality | 2023 |
| Seven Cities Holdings Limited | Financial services | 2025 |
| Seven Hills Property Holdings Limited | Real estate | 2022 |
| Seven House Fashion Ltd | Wholesale & retail | 2020 |
| Seven Hundred and Eighty SIX Limited | Real estate | 2025 |
| Seven Intercontinental Trade Ltd | Wholesale & retail | 2022 |
| Seven Palms for Agricultural Reclamation Ltd | Agriculture & fishing | 2025 |
| Seven Seas HR Management Ltd | Construction | 2022 |
| Seven Silva Limited | Financial services | 2013 |
| Seven Stalks Limited | Real estate | 2021 |
| Seven Star (Midlands) Ltd | Hospitality | 2025 |
| Seven Stars Cleaning Ltd | Administrative & support | 2025 |
| Seven Steps Healthcare Limited | Health & social care | 2015 |
| Seven Success Ltd | Health & social care | 2010 |
| Seven Tea Ltd | Hospitality | 2012 |
| Sevenleaf Medical UK Ltd | Wholesale & retail | 2025 |
| Seventynine Marketing Ltd | Professional & scientific | 2023 |
| Severn Dove Ltd | Wholesale & retail | 2025 |
| Severn Drives & Energy Limited | Administrative & support | 2004 |
| Severn Surgery Limited | Health & social care | 2022 |
| Sevn HQ Ltd | Wholesale & retail | 2026 |
| Sevyndaes Ltd | Transport & logistics | 2025 |
| SEW Systems Limited | Manufacturing | 1996 |
| Seyma Burgers Limited | Hospitality | 2023 |
| Seymour Forest Ltd | Wholesale & retail | 2025 |
| SF Leicester Limited | Construction | 2012 |
| SF One Ltd | Professional & scientific | 2025 |
| SF Ripple Limited | Other services | 2021 |
| SF RS Pharma Limited | Health & social care | 2023 |