| Star Logistics Limited | | 2006 |
| Star Oyster Limited | Arts & recreation | 1990 |
| Star's Property Investments Limited | Real estate | 2025 |
| Starcastle Management Limited | Professional & scientific | 1998 |
| Starex Innovation World Ltd | Professional & scientific | 2026 |
| Starke Media Ltd | Information & communication | 2021 |
| Starlets Business Ltd | Health & social care | 2022 |
| Starling Structures Ltd | Construction | 2022 |
| Starpharma Ltd | Health & social care | 2022 |
| Starquest Publishing Ltd | Information & communication | 2024 |
| Stars Edge Ltd | Manufacturing | 2023 |
| Starsailor Investments Limited | Real estate | 2018 |
| Start Point Advisory Limited | Professional & scientific | 2021 |
| Startafran Ltd | Professional & scientific | 2021 |
| Startpoint Resourcing Ltd | Administrative & support | 2025 |
| Statement Partnerships Ltd | Other services | 2023 |
| Statement Stays Ltd | Real estate | 2025 |
| Static Void Tech Limited | Extraterritorial | 2021 |
| Station Road Management Limited | Households | 1985 |
| Stay Fit Stay Young Ltd | Wholesale & retail | 2025 |
| Steamtech Floor Cleaning Ltd | Administrative & support | 2021 |
| Steamx Cleaners Ltd | Other services | 2025 |
| Steamx Services Ltd | Information & communication | 2019 |
| Steel Rivers Holdings Ltd | Real estate | 2026 |
| Steely Resolve Limited | Health & social care | 2015 |
| Steenvlinder UK Holdings Limited | Construction | 2020 |
| Stefan Orban & Co Limited | Professional & scientific | 2017 |
| Stefanos IT Limited | Information & communication | 2011 |
| Stein Capital Group Ltd | Financial services | 2025 |
| Stein Logistics Ltd | Financial services | 2025 |
| Steiner Hops Limited | Agriculture & fishing | 1974 |
| Stella Lamp Company Limited | Professional & scientific | 1964 |
| Stellies Limited | Real estate | 2020 |
| Stena Consulting Limited | Wholesale & retail | 2021 |
| Stephaniejaneallen Ltd. | Real estate | 2014 |
| Stephen Bendall Limited | Health & social care | 2010 |
| Stephen Thornton Limited | Professional & scientific | 2015 |
| Stephen Turner Acoustics Limited | Professional & scientific | 2015 |
| Stephens Consulting Limited | Professional & scientific | 2014 |
| Steve Middleton Solutions Limited | Professional & scientific | 2010 |
| Stevens & Bolton LLP | | 2004 |
| Stevens & Bolton Trustees Limited | Professional & scientific | 2000 |
| Stezard Ltd | Information & communication | 2025 |
| Stf.Ns Ltd | Administrative & support | 2025 |
| Sthaler Limited | Information & communication | 2012 |
| Stillgood Ltd | Extraterritorial | 2023 |
| Stingray Squash Machines Limited | Manufacturing | 2018 |
| Stock and Bokeh Ltd. | Information & communication | 2016 |
| Stock Morgan Limited | Wholesale & retail | 1974 |
| Stone Design and Development Limited | Real estate | 2020 |
| Stoneamp Limited | Professional & scientific | 2022 |
| Stonegate Homes (Reading) Limited | Construction | 2020 |
| Stonegate Homes (Trowbridge) Limited | Construction | 2020 |
| Stonegate Homes (Westbrook Mills 1) Limited | Construction | 2022 |
| Stonekeep Services Limited | Professional & scientific | 2017 |
| Stonerose Events Co Ltd | Hospitality | 2023 |
| Stonerose Pizza Co Ltd | Hospitality | 2018 |
| Stortech Electronics Limited | Manufacturing | 1988 |
| Stortford Homes Limited | Real estate | 2016 |
| Storyboard Consulting Ltd | Professional & scientific | 2018 |
| Stott and Stott Studio Limited | Professional & scientific | 2025 |
| Stoughton Preschool Limited | Education | 2011 |
| Stoughton Tree Care Limited | Agriculture & fishing | 2013 |
| Stovell Place Residents Management Company Limited | Households | 2024 |
| Stow Real Estate Management Limited | Real estate | 2018 |
| Stradbally Holdings | Professional & scientific | 2022 |
| Strangford Management Limited | Real estate | 2015 |
| Strap MED Medical Supplies Limited | Wholesale & retail | 2013 |
| Strat Management UK Limited | Wholesale & retail | 2014 |
| Strat Tech Ltd. | Professional & scientific | 2017 |
| Strata Technology Limited | Professional & scientific | 1998 |
| Strategic AI Ltd | Information & communication | 2020 |
| Strategic Investigations Ltd | Administrative & support | 2025 |
| Strategic Software Partners Limited | Professional & scientific | 1994 |
| Stratfieldsaye Management Limited | Households | 1986 |
| Stratford City Hotels Limited | Hospitality | 2011 |
| Strathmore Advisory Limited | Professional & scientific | 2018 |
| Stratum Reservoir (UK) Holdings, Ltd. | Financial services | 2018 |
| Stratum Reservoir (UK) International Holdings, Ltd. | Financial services | 2018 |
| Stratum Reservoir (UK), Ltd. | Financial services | 2018 |
| Stratum Topco Limited | Financial services | 2021 |
| Straun' 66 Epsom Road Guildford Management Company Limited | Households | 1988 |
| Strawberry Corner Limited | Professional & scientific | 2024 |
| Street Cups Ltd | Hospitality | 2023 |
| Stretched & Fired Cafes Ltd | Hospitality | 2024 |
| Stretched & Fired Shambles Ltd | Hospitality | 2023 |
| Strike Hero Ltd | Manufacturing | 2026 |
| Strive Roofing and Construction Ltd | Construction | 2023 |
| Strong Pilates Franchising UK Limited | Arts & recreation | 2024 |
| Strong Rock Ltd | Real estate | 2020 |
| Stronghold Roofing and Home Improvements Limited | Construction | 2026 |
| Stroud Embedded Systems Ltd | Information & communication | 2020 |
| Stroudbridge Investments LLP | | 2021 |
| Structural Designs Limited | Professional & scientific | 2020 |
| Structural Waterproofing Solutions Limited | Extraterritorial | 2011 |
| Stsa Services Ltd | Health & social care | 2022 |
| Stuart Gallacher Business Solutions Limited | Professional & scientific | 2014 |
| Stuart Hollington Design Ltd | Professional & scientific | 2021 |
| Stuart Mcphail Consultancy Limited | Other services | 2014 |
| Student Health Guide Limited | Information & communication | 2016 |