| Solving Communications Ltd | Bristol | 2025 |
| Solvitt Ltd | Epping | 2024 |
| Solway Direct Limited | Carlisle | 2005 |
| Solway Skip Hire Ltd | Dalbeattie | 2024 |
| Soma Control Systems Ltd | Kenilworth | 2022 |
| Soma Group of Companies Limited | Kenilworth | 2022 |
| Soma Services Limited | Kenilworth | 2000 |
| Somerset Grab Hire Ltd | Chard | 2018 |
| Sometal Limited | Watford | 2022 |
| Somex Ltd | Ruislip, | 2025 |
| Sonam.Ai Ltd | Cobham | 2024 |
| Sonas Textile Limited | Wellingborough | 2007 |
| Sonny's Sweeping Ltd | Crawley | 2014 |
| Sonny’S Skips Ltd | Littleborough | 2022 |
| Soors Ltd | Swansea | 2010 |
| Sophos Operational Solutions Ltd | South Ockendon | 2015 |
| Sora Tech Logistics Ltd | Bolton | 2025 |
| Sorin Iobagi Ltd | Brentwood | 2025 |
| Sorrell's Groundworks Ltd | Chesterfield | 2023 |
| Sort & Save Limited | Cowbridge | 2018 |
| Sorted by Declutter Limited | Bedford | 2026 |
| Sorted Skips Limited | Shawbury | 2015 |
| Sortera Limited | Edmonton | 1986 |
| Sortology Limited | Stockton-On-Tees | 2011 |
| Sortridge and Grimstone Leat CIC | Yelverton | 2025 |
| SOS Drains Limited | Dumfries | 2008 |
| SOS KIT AID Ltd | Croydon | 2010 |
| SOS Scrap Ltd | Cinderford | 2026 |
| SOS Waste Ltd | Glasgow | 2009 |
| Sospan Skips Limited | Llanelli | 1999 |
| Sota Services Ltd | London | 2025 |
| Soteria Waste Ltd | Knottingley | 2025 |
| Soterion Limited | Bromsgrove | 2009 |
| Sotherton Corner Management Company Limited | Beccles | 2000 |
| Source for Business Limited | Exeter | 2013 |
| Sourhall Cottages Water Company Ltd | Todmorden | 2025 |
| South Ayrshire Environmental Services Limited | Falkirk | 2022 |
| South Bucks Effluent Company Limited | Stanmore | 2013 |
| South Coast Clearance Ltd | Barrow-In-Furness | 2019 |
| South Coast Clearance Services Ltd | Bolton | 2023 |
| South Coast Drain Services Ltd | Poole | 2019 |
| South Coast HPD Ltd | London | 2026 |
| South Coast Metal Recycling & Waste Clearance Ltd | Southampton | 2022 |
| South Coast Pickers Ltd | Portsmouth | 2025 |
| South Coast Pure Water Ltd | Broadstairs | 2026 |
| South Coast Waste Holdings Limited | Portsmouth | 2024 |
| South Coast Waste Limited | Portsmouth | 2024 |
| South Coast Water Mains Ltd | Littlehampton | 2026 |
| South Coast Water Solutions Limited | Bournemouth | 2019 |
| South Coast Water Supplies Limited | Bournemouth | 2025 |
| South Downs Limited | Havant | 2001 |
| South Downs Waste Services Limited | London | 2002 |
| South East Asbestos Surveys Ltd | Basildon | 2014 |
| South East Direct Waste Solutions Ltd | Dunstable | 2024 |
| South East Drainage Ltd | Chatham | 2019 |
| South East Drainage Services Limited | Waterlooville | 2010 |
| South East Environmental Services Limited | Eastbourne | 2018 |
| South East London Combined Heat and Power Limited | London | 1990 |
| South East Northumberland Recycling Limited | Bedlington | 1999 |
| South East Recycling Ltd | Dover | 2024 |
| South East Sweepers Ltd | Rochester | 2023 |
| South East Tankers Ltd | Haywards Heath | 2023 |
| South East Tyre Recycling Limited | Ashford | 2025 |
| South East Waste Management Ltd | Dartford | 2024 |
| South East Water Limited | Snodland | 1992 |
| South Elmsall Quarries Limited | Ossett | 1963 |
| South Hylton and Pennywell Enterprise CIC | Sunderland | 2024 |
| South Manchester Plastic Ltd | Manchester | 2019 |
| South Manchester Skips Ltd | Manchester | 2025 |
| South Reclamation Ltd | Billingshurst | 2025 |
| South Staffordshire Water PLC | West Midlands | 1991 |
| South Thames Waste Removal Ltd | Epsom | 2024 |
| South Tyne & Wear Energy Recovery Holdings Ltd | Manchester | 2010 |
| South Tyne & Wear Energy Recovery Ltd | Manchester | 2010 |
| South Wales Tyre Recycling Ltd | Llanelli | 2019 |
| South West Composting Ltd | Plymouth | 2011 |
| South West Computer Recycling Limited | Wellington | 2014 |
| South West Drainage Services Ireland Ltd | Lisburn | 2022 |
| South West Drainage Solutions Ltd | Dumfries | 2026 |
| South West Oils Ltd | Ruislip | 2020 |
| South West Paper Recycling Ltd | Braintree | 2013 |
| South West Project Services Limited | Chichester | 2024 |
| South West Tank Supplies Ltd | Eastleigh | 2021 |
| South West Tippers Ltd. | Chard | 2016 |
| South West Tyre Recycling Ltd | Saltash | 2020 |
| South West Water Limited | Exeter | 1989 |
| South West Wood Products Limited | Penrith | 2009 |
| South Yorkshire Metals Ltd | Northampton | 2008 |
| Southall Maintenance Ltd | Shrewsbury | 2026 |
| Southam Water Sytems Limited | Kings Somborne | 2015 |
| Southampton Grab Hire Limited | Southampton | 2015 |
| Southampton Scrap Metal Limited | Southampton | 2022 |
| Southampton Steel Industrial Services Limited | Fareham | 2025 |
| Southampton Wood Recycling | Southampton | 2012 |
| Southbank Pest Control Ltd | York | 2019 |
| Southeast Waste Solutions Ltd | London | 2026 |
| Southeast Waste Water Removal Limited | Chatham | 2025 |
| Southerham Services Limited | Lewes | 1998 |
| Southern Counties Watersoftener Services Limited | Downton Salisbury | 1994 |
| Southern Drainage & Water Limited | Bournemouth | 2016 |