| Scothern Roofing Ltd | Construction | 2023 |
| Scott Richard Mccluskey Ltd | Extraterritorial | 2025 |
| Scott’S Floor Restoration Ltd | Construction | 2025 |
| Scph Limited | Construction | 2014 |
| SCW Property Ltd | Real estate | 2021 |
| SD Property Maintenance Limited | Construction | 2017 |
| Sdormer Limited | Hospitality | 2019 |
| SDR Holdings Limited | Wholesale & retail | 2025 |
| Sea Bidding Services Limited | Administrative & support | 2015 |
| Sea Consultancy Ltd | Professional & scientific | 2019 |
| Sean Austin Consulting Ltd | Professional & scientific | 2020 |
| Seax & Rose Ltd | Professional & scientific | 2026 |
| Securafen Ltd | Construction | 2009 |
| Secure Consulting Limited | Professional & scientific | 2025 |
| Secure My Sale Ltd | Real estate | 2020 |
| Security Technologies Ltd | Professional & scientific | 2024 |
| Secuwrite Limited | Wholesale & retail | 2004 |
| Sedere Ltd | Manufacturing | 2023 |
| Sefgrill Limited | Hospitality | 2022 |
| Segrave LLP | | 2010 |
| Seguri Ltd | Administrative & support | 2026 |
| Selah Group Limited | Information & communication | 2022 |
| Selected Enforcement Limited | Administrative & support | 2016 |
| Selentus Science Limited | Professional & scientific | 2016 |
| Sellfor Goods Limited | Wholesale & retail | 2023 |
| SEN Betweeners Hub UK Ltd | Education | 2026 |
| Sencillo Designs Ltd | Wholesale & retail | 2019 |
| SEP Contracts Ltd | Construction | 2018 |
| Serenity Community Living Limited | Health & social care | 2026 |
| Serenity Flooring Lincs Limited | Wholesale & retail | 2024 |
| Serenity Residential Ltd | Public administration | 2026 |
| Sergejtransport Ltd | Transport & logistics | 2015 |
| Serkan in Style Ltd | Other services | 2022 |
| Seth Roberts Ltd. | Real estate | 2025 |
| Severn (Lincs) | Financial services | 2022 |
| SF Telecoms Limited | Information & communication | 2010 |
| SGM Recycled Plastics Ltd | Manufacturing | 2021 |
| Shadhakshi Technology Limited | Information & communication | 2012 |
| Shadow Moon Cosmetics Ltd | Wholesale & retail | 2021 |
| Sharmans Agricultural Limited | Wholesale & retail | 1924 |
| Sharon Galley Consultancy Services Ltd | Professional & scientific | 2025 |
| Sharon Stower Consultancy Ltd | Professional & scientific | 2011 |
| Shawfern Ltd | Real estate | 2021 |
| Shear Energy Limited | Energy | 2014 |
| Sheard’S Tree Service Ltd | Administrative & support | 2024 |
| Shepherd Consulting Group Ltd | Professional & scientific | 2019 |
| Sherwood Accountants Limited | Professional & scientific | 2022 |
| Shewan Holdings Limited | Financial services | 2024 |
| SHH! PR Limited | Professional & scientific | 2023 |
| Shine and Secure Property Limited | Real estate | 2025 |
| Shiningsea Ltd | Manufacturing | 2020 |
| Shipley Fabrications Limited | Manufacturing | 1982 |
| Shipley Structures Holding Co Limited | Financial services | 2026 |
| Shipley Structures Limited | Construction | 1982 |
| Shoozeple Ltd | Wholesale & retail | 2021 |
| Shorrock Design Ltd | Professional & scientific | 2013 |
| Shots&Gigglesbar Limited | Hospitality | 2025 |
| Siafu PR Ltd | Agriculture & fishing | 2015 |
| Sideman & Sons Limited | Financial services | 1929 |
| Sideman Holdings Ltd | Financial services | 2026 |
| Sierra Golf Limited | Real estate | 2014 |
| Signature Travel Limited | Hospitality | 2022 |
| Silver Pear Communications Ltd | Professional & scientific | 2020 |
| Silverants Limited | Professional & scientific | 2023 |
| Silverback (Barrowby) Ltd | Professional & scientific | 2025 |
| Silverman Consultancy Ltd | Professional & scientific | 2025 |
| Simic Developments Limited | Construction | 2010 |
| Simon Bailey Hairdressing Limited | Other services | 2014 |
| Simon Kirby Consulting Ltd | Professional & scientific | 2024 |
| Simple Learn Ltd | Education | 2018 |
| Simpson Arboriculture Limited | Agriculture & fishing | 2016 |
| Simtrim Limited | Wholesale & retail | 2016 |
| Simubyte Limited | Information & communication | 1996 |
| Singhs & Sons Ltd | Real estate | 2025 |
| Sips Building Services Ltd | Construction | 2017 |
| SIR John Aird & Family Limited | Financial services | 2015 |
| Sisu Hair Collective Limited | Wholesale & retail | 2023 |
| SIX7 Contracts Ltd | Construction | 2025 |
| SJ Holding Company (Grantham) Limited | Financial services | 2020 |
| SJV Food Solutions Ltd | Hospitality | 2018 |
| Skegness and Ingoldmells Caravan Sales Company Limited | Hospitality | 1968 |
| Skelton Farms (Ponton) Limited | Agriculture & fishing | 2013 |
| Skye Design Limited | Professional & scientific | 2008 |
| Skygain Limited | Professional & scientific | 2015 |
| Skygazer Limited | Professional & scientific | 2011 |
| SL Preparations Ltd | Wholesale & retail | 2026 |
| Slaine Estates Limited | Real estate | 2017 |
| SLC Ecology Limited | Professional & scientific | 2019 |
| Sleeping Dragons Ltd | Manufacturing | 2025 |
| Slipstream A.S.H Limited | Professional & scientific | 2005 |
| Slyk Life Ltd | Financial services | 2015 |
| Smart Money Solutions Limited | Financial services | 2002 |
| Smart Pets Grantham Limited | Other services | 2020 |
| Smart Street Property Ltd | Real estate | 2025 |
| Smart-Ag Ltd | Agriculture & fishing | 2025 |
| Smib Ltd | Real estate | 2021 |
| Smith Electrical Contractors 2017 Ltd | Construction | 2017 |
| Smithy's Collectibles Ltd | Wholesale & retail | 2025 |
| SNB Grounds Care Ltd | Administrative & support | 2023 |
| Snow FOX Transport Ltd | Transport & logistics | 2022 |