| Shires Developments (Holdings) Limited | Dronfield | 2007 |
| Shires Developments (Langley Marina) Limited | Cleckheaton | 2007 |
| Shires Developments (Roundwood) Limited | Rotherham | 2007 |
| Shires Developments Limited | Dronfield | 1995 |
| Shires PES Ltd | Wokingham | 2026 |
| Shivam Minerals UK Ltd | Salford | 2024 |
| Shore & Marine Inspection Ltd. | Glasgow | 2014 |
| Shore to Coast Services Ltd | Great Yarmouth | 2025 |
| Shoreham Cement Works Limited | Chorley | 2015 |
| Shrawley Mining Holdings Limited | London | 2021 |
| Shropshire Sand & Gravel Company Limited | Telford | 2005 |
| Shuka Minerals PLC | London | 2004 |
| SI Offshore Ltd | Whitby | 2017 |
| Siam Orca Asia (UK) Ltd | Blackpool | 2025 |
| Sibelco Minerals and Chemicals (Holdings) Limited | Talke | 1951 |
| Sibelco UK Limited | Talke | 1957 |
| Siberian Resources Limited | Horsham | 2014 |
| Sidaa (UK) Limited | Beckenham | 2024 |
| Sidler Dynamic Engineering (UK) Ltd | Stafford | 2002 |
| Sierra Rutile (UK) Limited | London | 2013 |
| Sierra Turks Global International Trading Gold and Petroleum Holding Ltd | Ruislip, | 2023 |
| Sigmafin Limited | London | 2017 |
| Sigmaroc PLC | London | 2004 |
| Sila Energy Limited | London | 2020 |
| Silica Mining Corporation Ltd | Birmingham | 2016 |
| Silica Sand Mold Limited | Clitheroe | 2006 |
| Silica United Resources Ltd | London | 2025 |
| Silver Bough Limited | Polegate | 2016 |
| Silver Bullet Petroleum Consultants Limited | | 2005 |
| Silver FOX Corp Limited | London | 2018 |
| Silverbridge Quarries Ltd | Belfast | 2022 |
| Silverdale Site Services Ltd | Leek | 2015 |
| Silverstone Mining and Materials Ltd | Waltham Abbey | 2026 |
| Simani Holdings Ltd | Birmingham | 2025 |
| Simel Incorporated Limited | London | 2019 |
| Simintrading &Consulting Co Ltd | London | 2024 |
| Simon Hunt (Strategic Services) Limited | Hook | 1996 |
| Simon Penrose Ltd | Newick | 2019 |
| Simply GEO Limited | London | 2011 |
| Simpson Quarries Limited | Pocklington | 2002 |
| Sinclair Bay Inspection Services Ltd | Wick | 2022 |
| Sinergy Global Solutions Ltd | London | 2019 |
| Singleton Birch Limited | Barnetby | 1875 |
| Singularity One (UK) Limited | Heathfield | 2014 |
| Sino Trade and Brokers Ltd | Beckenham | 2025 |
| Sinochem Guomao (Shandong) Fertilizer Import & Export Co., Ltd | London | 2025 |
| Sinochem U.K. Ltd. | London | 2025 |
| Sinoconve Belt Co., Ltd | Beckenham | 2014 |
| Sinok Energy Ltd | Staines-Upon-Thames | 2018 |
| Sinok Exploration and Production Limited | Staines-Upon-Thames | 2014 |
| Sinok OIL & GAS Ltd | Staines-Upon-Thames | 2018 |
| Sintana Energy Angola Holdings Limited | London | 2026 |
| Sirius Gemstones Ltd. | London | 2016 |
| Site Integrity Management Limited | Blackpool | 2017 |
| Siyouni Trading Limited | London | 2026 |
| SJB Solutions Ltd | Wick | 2021 |
| SJC NE Limited | Wallsend | 2015 |
| SJF Drilling Consultants Ltd | Buckie | 2022 |
| SJL Technical Solutions Limited | Lytham St. Annes | 2017 |
| SJR Specialist Consultants Limited | Wokingham | 2011 |
| SJS Services (Aberdeen) Ltd | Inverurie | 2015 |
| SK Global Impex Ltd | London | 2023 |
| SK Rigging Lifting & Transport Ltd | Stockton-On-Tees | 2025 |
| Skae Ship Contractors Limited | Great Yarmouth | 1997 |
| SKD Shore Limited | Montrose | 2003 |
| Skene Group Construction Services Limited | Ayrshire | 2000 |
| Sker Solutions Limited | Dundee | 2021 |
| Skilled Simian Services Ltd | North Walsham | 2026 |
| Skills Management Ltd | London | 2023 |
| Skoidos Limited | Shaftesbury | 2026 |
| Skopti Critical Minerals Ltd | Bromley | 2025 |
| Sky Jenesis Transport Ltd | Bromley | 2019 |
| Skydatasol Holdings Ltd | London | 2022 |
| Skylex Limited | Peterhead | 2026 |
| Skylines Limited | | 2000 |
| Skyworth Investment Limited | South Ockendon | 2018 |
| Slateburn Services Ltd | Banchory | 2023 |
| SLC Structural & Piping Services Ltd | Lowestoft | 2024 |
| Sleningford Assets Ltd | Ripon | 2025 |
| Slew Left Limited | Hessle | 2019 |
| Slieve Gallion Ltd | Belfast | 2018 |
| Slinter Mining Company Limited | Matlock | 1946 |
| SLM Well Services Limited | Dundee | 2013 |
| Slmj Well Services Ltd | Montrose | 2005 |
| Slothianrigging Ltd | Edinburgh | 2025 |
| SMA Benelux Ltd | Bolton | 2024 |
| Small & Artisanal Mining Services Limited | London | 2024 |
| Smart Reamer Drilling Systems Ltd | Slough | 2009 |
| Smartwellservices Ltd | Westhill | 2014 |
| Smashing Rocks Ltd | London | 2021 |
| SMB Strategic Mining Consulting Ltd | Kington | 2022 |
| SMC Inspections Limited | Peterhead | 2024 |
| SMG Gardening (UK) Ltd. | London | 1994 |
| SMG Gold Limited | London | 2024 |
| SMG Mechanical Solutions Ltd | Morpeth | 2021 |
| SMG OFF Shore Ltd | Morpeth | 2019 |
| Smiben UK Limited | Crawley | 2004 |
| Smith Aggregates & Builders Merchants Ltd | Milton Keynes | 2016 |
| Smith Construction Group Limited | Milton Keynes | 1994 |
| Smith Engineering (Cumbria) Ltd | Blackpool | 2019 |