| Spire Farms Ltd | Agriculture & fishing | 2021 |
| Spire Windows Systems Ltd | Construction | 1999 |
| Spires Aviation Design and Production Ltd | Professional & scientific | 2009 |
| Splash About International Limited | Wholesale & retail | 2005 |
| Spoken Forum Community Interest Company | Other services | 2026 |
| Spoonycooks Ltd | Hospitality | 2017 |
| Sportsfunds (Boston) Limited | Arts & recreation | 1962 |
| Sportuno Limited | Information & communication | 2020 |
| Spotcheck Environmental Management & Hygiene Services Limited | Professional & scientific | 2024 |
| Spouse Energy & Communications Ltd | Administrative & support | 2002 |
| SPP IP Limited | Administrative & support | 2020 |
| SPR Scaffolding Ltd | Construction | 2019 |
| Spring Business Limited | Other services | 2007 |
| Spring Grimsby Ltd | Wholesale & retail | 2022 |
| Spring Hill Letting Services Ltd | Administrative & support | 2011 |
| Sprinterprint Limited | Manufacturing | 1991 |
| Spudgun Holdings Ltd | Real estate | 2022 |
| Square and Compass Normanton on Trent Ltd | Hospitality | 2018 |
| Square Cloud Learning Ltd | Education | 2016 |
| Square Fayre Limited | Hospitality | 2014 |
| Square PEG Recruitment Yorkshire (ENW) Limited | Administrative & support | 2017 |
| Squareone Systems Ltd | Information & communication | 2022 |
| Squeaky Clean Truck Wash Limited | Other services | 2009 |
| SR Facilities Management Limited | Administrative & support | 2019 |
| SR Group (Lincs) Ltd | Construction | 2022 |
| SRB Insulation Limited | Construction | 2016 |
| Sri-Transport Ltd | Transport & logistics | 2016 |
| SS Family Partners Limited | Professional & scientific | 2015 |
| SS Plumbing & Heating (Grimsby) Ltd | | 2012 |
| SSA Medical Services Ltd | Health & social care | 2018 |
| Ssendam Ltd | Transport & logistics | 2018 |
| Sslg Processing Ltd | Manufacturing | 2019 |
| Ssvg Limited | Health & social care | 2021 |
| ST Andrew's Hospice Limited | Health & social care | 1992 |
| ST Andrews Hospice (Trading) Limited | Wholesale & retail | 1992 |
| ST Catherines Properties Limited | Construction | 2016 |
| ST Engineering Consulting Limited | Professional & scientific | 2024 |
| ST George's Mill Limited | Real estate | 2017 |
| ST Johns Fold Management Limited | Real estate | 2018 |
| ST Margarets Pre-School Laceby | Education | 2006 |
| ST Martins Preparatory School Limited | Education | 2015 |
| ST Paul's View Management Company Limited | Real estate | 2013 |
| ST Peter's View Management Company Limited | Real estate | 2006 |
| ST Safety Services Ltd | Other services | 2021 |
| St-Kam Ltd | Transport & logistics | 2025 |
| ST. Giles Property Developers (Grimsby) Limited | Construction | 2014 |
| ST. Michaels Road 1967 Limited | Extraterritorial | 2014 |
| St.James'Tennis Club(Grimsby)Limited | Arts & recreation | 1938 |
| Stable Mews (Cleethorpes) Limited | Households | 2024 |
| Stabrizi Limited | Health & social care | 2026 |
| Stage 11 Productions Limited | Administrative & support | 2022 |
| Staintech Limited | Manufacturing | 2001 |
| Stairway Audio Limited | Manufacturing | 2015 |
| Stakeout Media Ltd | Arts & recreation | 2012 |
| Stalfreight Ltd | Transport & logistics | 2021 |
| Stallgroup Ltd | Financial services | 2024 |
| Stallingborough Car Centre Limited | Wholesale & retail | 1995 |
| Stallingborough Grange Hotel Limited | Hospitality | 2003 |
| Stallingborough Truck Park Ltd | Transport & logistics | 2016 |
| Stampede Network Ltd | Other services | 2025 |
| Stan's Window and Door Hardware Limited | Wholesale & retail | 2010 |
| Stani's Tricore Investments Ltd | Financial services | 2025 |
| Stanton Builders Ltd | Construction | 2011 |
| Stanway International Limited | Professional & scientific | 1993 |
| Star Connection Ltd | Wholesale & retail | 2021 |
| Stardelta Group Limited | Financial services | 2024 |
| Stardelta Holdings Limited | Financial services | 2023 |
| Stardelta Ltd | Manufacturing | 2004 |
| Stargazer Property Limited | Real estate | 2019 |
| Starline Windows Limited | Construction | 2003 |
| Station Mews (New Waltham) Management Company Limited | Households | 2009 |
| Station Mews Development Company Limited | Construction | 2006 |
| Station Road Management Company (Tetney) Limited | Professional & scientific | 2019 |
| Status Property People Ltd | Real estate | 2023 |
| Stawik Transport Ltd | Transport & logistics | 2014 |
| Stay Social LDN Limited | Professional & scientific | 2023 |
| Steelbook Central Ltd | Wholesale & retail | 2014 |
| Stefan&Cornel Transport Ltd | Transport & logistics | 2025 |
| Stelarc Limited | Professional & scientific | 2014 |
| Stella & ALF Ltd | Professional & scientific | 2012 |
| Stellarscope Media Ltd | Professional & scientific | 2020 |
| Stem Accountants Limited | Professional & scientific | 2024 |
| Stem Kits Limited | Education | 2024 |
| Stem Stars With Izzy Limited | Education | 2025 |
| Stennetts Joinery Ltd | Construction | 2018 |
| Stennetts Property and Maintenance Ltd | Real estate | 2018 |
| Stephen Bennett Golf Limited | Wholesale & retail | 2013 |
| Stephen Lightfoot Limited | Other services | 2002 |
| Stephen Salons Limited | Other services | 2024 |
| Stephenson Property Company Limited | Real estate | 1972 |
| Stepwise Projects Limited | Construction | 2025 |
| Sterling Place Apartments Limited | Professional & scientific | 2004 |
| Sterling Place Highways Limited | Households | 2004 |
| Steve Chalder Heating and Electrical Ltd | Construction | 2018 |
| Steve Fyfe Engineering and Technical Solutions Ltd | Professional & scientific | 2014 |
| Steve Hilldrith Interiors Limited | Manufacturing | 1986 |
| Steve Keightley Window Company Limited | Construction | 2002 |
| Steve Pearce (Grimsby) Limited | Transport & logistics | 1985 |
| Steve Wright Haulage Ltd | Transport & logistics | 2014 |
| Steven Clough Management and Consultancy Services Ltd | Education | 2015 |