| Sims Energy LLP | | 2022 |
| Sircar (Builders) Limited | Construction | 1977 |
| Sircar Holdings Ltd | Financial services | 2020 |
| Sircar Properties Ltd | Real estate | 2020 |
| SJB Hampshire Ltd | Wholesale & retail | 2025 |
| SJC Transport Limited | Transport & logistics | 2024 |
| SJL Property Group Ltd | Real estate | 2025 |
| Skin Place Ltd | Other services | 2025 |
| Skscenic Ltd | Arts & recreation | 2014 |
| Skyeline Ltd | Extraterritorial | 2012 |
| Skylark Fields Management Company Limited | Real estate | 2020 |
| SLC Maintenance Limited | Construction | 2015 |
| Small Organic Spaces Limited | Manufacturing | 2018 |
| Small Wonders Community Programme Ltd | Health & social care | 1989 |
| Smeaton Wood Holdings Limited | Financial services | 2025 |
| Smeaton Wood Limited | Agriculture & fishing | 2009 |
| Smwt Ltd | Professional & scientific | 2013 |
| Soken Engineering Limited | Manufacturing | 2015 |
| Somborne Estate Limited | Agriculture & fishing | 2008 |
| Sophia Davenport Ltd | Wholesale & retail | 2019 |
| Sophsdram Pet Services Ltd | Agriculture & fishing | 2025 |
| South Lane Real Estate Ltd | Real estate | 2026 |
| South Wales Telecoms Ltd | Information & communication | 2026 |
| Spark Visions Ltd | Wholesale & retail | 2024 |
| Sparkle & Shine Ltd | Administrative & support | 2020 |
| Sparkling Ovens Limited | Administrative & support | 2003 |
| Spartacus Properties (Chester) Limited | Professional & scientific | 1998 |
| Spartan Fitness Holdings Limited | Arts & recreation | 2019 |
| Spartan Strength and Fitness Ltd | Arts & recreation | 2019 |
| Spear Sauna Limited | Other services | 2024 |
| Spice Heaven (Whitchurch) Ltd | Hospitality | 2014 |
| Spice Heaven Indian Ltd | Hospitality | 2025 |
| Spiritual Inspiration Ltd | Health & social care | 2013 |
| Sports and Vintage Motors (Shrewsbury) Limited | Wholesale & retail | 1966 |
| Spraggs Stationery Limited | Wholesale & retail | 2023 |
| Spring Equestrian Changing Lives CIC | Education | 2024 |
| Springbank Contracting Ltd | Manufacturing | 2017 |
| Springcare (Albrighton) Limited | Health & social care | 2012 |
| Springcare (Aspley) Limited | Health & social care | 2022 |
| Springcare (Brockhampton) Limited | Health & social care | 2024 |
| Springcare (Bulwell) Limited | Health & social care | 2023 |
| Springcare (Dalton) Limited | Health & social care | 2025 |
| Springcare (Davenham) Limited | Health & social care | 2005 |
| Springcare (Eastwood) Limited | Health & social care | 2023 |
| Springcare (FT) Limited | Health & social care | 2023 |
| Springcare (Hatton) Limited | Health & social care | 2005 |
| Springcare (Hinton) Limited | Health & social care | 2022 |
| Springcare (Ilkeston) Limited | Health & social care | 2022 |
| Springcare (Kings Court) Limited | Health & social care | 1981 |
| Springcare (Knutsford) Limited | Health & social care | 2011 |
| Springcare (Macclesfield) Ltd | Health & social care | 2016 |
| Springcare (Oadby) Limited | Health & social care | 2024 |
| Springcare (River Meadows) Limited | Health & social care | 1992 |
| Springcare (Sandiway) Limited | Health & social care | 2006 |
| Springcare (Shawbury) Limited | Health & social care | 2023 |
| Springcare (Southport) Limited | Health & social care | 2025 |
| Springcare (ST Helens) Limited | Health & social care | 2025 |
| Springcare (Stafford) Limited | Health & social care | 2025 |
| Springcare (Weston) Limited | Health & social care | 2004 |
| Springcare (Wythenshawe) Limited | Health & social care | 2024 |
| Springcare (Yockleton) Limited | Health & social care | 2005 |
| Springcare Investment 1 Limited | Health & social care | 2023 |
| Springcare Limited | Health & social care | 2001 |
| Springcare NO. 2 Limited | Health & social care | 2023 |
| Springcare NO.3 Limited | Health & social care | 2023 |
| Springcare NO.4 Limited | Health & social care | 2012 |
| Springcare NO.5 Limited | Health & social care | 2023 |
| Springcare NO.6 Limited | Health & social care | 2024 |
| SSK Productions Limited | Information & communication | 2000 |
| ST Catherine's (Dodington) Limited | Arts & recreation | 2011 |
| ST IVO Properties Ltd | Real estate | 2025 |
| ST. Dominic's Developments (UK) Limited | Real estate | 2012 |
| ST20 Holdings Ltd | Real estate | 2020 |
| Stacey International Limited | Wholesale & retail | 2008 |
| Stafford Tanning Limited | Other services | 2023 |
| Stagebolt Limited | Information & communication | 2013 |
| Stan Richards & Sons Limited | Construction | 2004 |
| Stanmere Developments Ltd | Construction | 2019 |
| Stanmere Rentals & Property Management Ltd | Real estate | 2021 |
| Stanza Style Interiors Ltd | Professional & scientific | 2012 |
| STARFISH22 Ltd | Real estate | 2023 |
| Stark Restaurants Ltd | Hospitality | 2023 |
| Steelcap’S Services Ltd | Professional & scientific | 2018 |
| Stelex Construction Equipment Ltd. | Manufacturing | 2004 |
| Stemila Limited | Information & communication | 2021 |
| Steve Leonard Productions Limited | Information & communication | 2007 |
| Stewart R. Greenberg Opticians Limited | Wholesale & retail | 1979 |
| Stockgrove Brickhill Systems Limited | Administrative & support | 2007 |
| Stockton Lettings Ltd | Real estate | 2022 |
| Stoneford Capital Ltd | Real estate | 2023 |
| Stoneleaze Associates Ltd | Professional & scientific | 2014 |
| Storage Designs Telford Ltd | Manufacturing | 2014 |
| Straight SIX Engineering Ltd | Wholesale & retail | 2020 |
| Stranders Electrical Limited | Construction | 2019 |
| Streetors.Com Limited | Public administration | 2024 |
| Strukt Ltd | Financial services | 2025 |
| Strukt Refurb Ltd | Construction | 2025 |
| Strukt Sales Ltd | Real estate | 2025 |
| Studio Bloc Ltd | Professional & scientific | 2019 |
| Studio Evans Limited | Professional & scientific | 2016 |