| Kent Enviropower Limited | Doncaster | 1994 |
| Kent Haulage & Construction Ltd | Leigh-On-Sea | 2015 |
| Kent Maintenance Ltd | Rochester | 2016 |
| Kent Movements Ltd | Cardiff | 2021 |
| Kent Oils Ltd | Birtley | 2025 |
| Kent RAG Consultancy Limited | Sheerness | 2022 |
| Kent Remediation Ltd | Rye | 2024 |
| Kent RO Systems Ltd. | Slough | 2016 |
| Kent Skips Recycling Ltd | Diss | 2024 |
| Kent Smart Recycling Limited | Maidstone | 2025 |
| Kent Waste & Gardening Solutions Limited | Chatham | 2025 |
| Kent Waste Bulk Collections Ltd | Chatham | 2025 |
| Kent Waste Collectors Ltd | Maidstone | 2023 |
| Kent Waste Group Ltd | Bromley | 2025 |
| Kent Waste Limited | Westerham | 2017 |
| Kent Waste Solutions Limited | Whitstable | 2013 |
| Kent Waste Water Services Limited | Chatham | 2020 |
| Kent Water Limited | London | 2014 |
| Kent Woodpeckers Ltd | Folkestone | 2024 |
| Kenward Waste Management Ltd | Leigh On Sea | 2001 |
| KEO Water Services Ltd | Halstead | 2025 |
| Kerdou Services Limited | London | 2026 |
| Kerfoot Metals Limited | St. Helens | 2011 |
| Kernow Clinical Waste Limited | Redruth | 2016 |
| Kernow Merchant Company Limited | Looe | 2025 |
| Kernow Scrap & Waste Solutions Ltd | Saltash | 2025 |
| Kernow Waste Disposal & Aggregates Ltd | Penryn | 2025 |
| Kerrs Private Water Solutions Ltd | Aberdeen | 2026 |
| Kes’S Waste Removals Limited | London | 2022 |
| Kettering Car Recycling Ltd | Kettering | 2019 |
| Kettering Textiles Limited | Wellingborough | 1991 |
| Kettles and Mettles Group Ltd | Dagenham | 2026 |
| KEV Jones Engineering Services Ltd | Gaerwen | 2025 |
| KEV Spurr Scrap & Waste Services Ltd | Ossett | 2025 |
| Kevsym Ltd | Rochester | 2024 |
| Key Asbestos Services Limited | Chessington | 2006 |
| Key Recycling Ltd | Brinklow | 2009 |
| Keypon Limited | Buxton | 2003 |
| KG Electrical & Cable Recycling Ltd | Ilkeston | 2026 |
| KGM Civil Services Ltd | Exeter | 2025 |
| KGZ Waste Removals Ltd | Harrogate | 2021 |
| KH Developments East Midlands Ltd | Bourne | 2019 |
| KHC Management Services Ltd | Ruislip | 2022 |
| KHE Fong Grandeur Ltd | Rayleigh | 2025 |
| Khera Oils Limited | Walsall | 2024 |
| Khurana Wines Ltd | Oxford | 2014 |
| Kiasu Drainage Limited | Sevenoaks | 2023 |
| Kiely Bros Waste Limited | Birmingham | 2020 |
| Kier Integrated Services Limited | Salford | 1966 |
| Kier Recycling CIC | Salford | 1996 |
| Kiing Ltd | Southampton | 2017 |
| Killadeas Quarry Management Company Limited | Enniskillen | 2012 |
| Killie Recycling Ltd | Kilmarnock | 2025 |
| Killoughery Waste Management Limited | Mitcham | 2001 |
| Kilmarnock Car Breakers Ltd | Kilmarnock | 2012 |
| Kilmarnock Recycling Ltd | Kilmarnock | 2012 |
| Kilmaronock Energy Limited | London | 2022 |
| Kilnbridge Environmental Services Ltd | London | 2017 |
| Kilnsey Private Water Supply Limited | North Yorkshire | 2006 |
| Kinetico UK Holdings Limited | Park Gate Chandlers Way | 2001 |
| King of Kings Ltd | Paisley | 2020 |
| King Recycling Ltd | Ilkeston | 2022 |
| Kingdom Property Care Ltd | Kirkcaldy | 2023 |
| Kingdom Recycling Limited | Uxbridge | 2025 |
| Kingfisher Drainage and Jetting Ltd | Braintree | 2021 |
| Kingpin Recycling Limited | Wem | 2018 |
| Kings Heath Demolition Limited | Birmingham | 2016 |
| Kings of Clearance Ltd | Basingstoke | 2024 |
| Kings of Rubbish Ltd | Perivale | 2017 |
| Kings Skip Hire Limited | Grays | 2019 |
| Kingsfield Close Wick (Bristol) Management Company Limited | Bristol | 2011 |
| Kingsfield Environmental Limited | Birdbrook | 2015 |
| Kingsfold Park Pumping Station Limited | Horsham | 1996 |
| Kingsgate Group Ltd | Bicester | 2025 |
| Kingsmen Grab Services Ltd | London | 2025 |
| Kingspit Transport Limited | Dartford | 2012 |
| Kingston Russell Water Co. Limited | Dorchester | 1994 |
| Kingston Skip Hire Limited | Hull | 2004 |
| Kingston Waste Clearance Ltd | New Malden | 2024 |
| Kingston Water Ltd | Swanage | 2024 |
| Kingswood Recycling Ltd | Woking | 2023 |
| Kington WET Waste Ltd | Trowbridge | 2025 |
| Kinney Recycling Ltd | Co Down | 2008 |
| Kintyre Recycling Limited | Campbeltown | 2006 |
| Kirby Composting Limited | Grantham | 2008 |
| Kirkby Skips Limited | Liverpool | 2000 |
| Kirkless Vehicle Salvage Limited | Wigan | 2012 |
| Kitalmine Ltd | Northolt | 2023 |
| Kitchen Clearance (UK) Ltd | Peterborough | 2011 |
| Kitson Recycling Limited | Bishops Waltham | 2006 |
| Kitsune Environmental Ltd | London | 2025 |
| Kive Environmental Services Ltd | Ferndale | 2026 |
| Kiwi Drainage Limited | Watford | 2004 |
| KJ Cleaning Limited | Leigh-On-Sea | 2003 |
| KJ Drainage Ltd | Manchester | 2015 |
| KJ Drains Ltd | Cardiff | 2019 |
| KJ Ventures Ltd | Herne Bay | 2026 |
| KJC Drainage Limited | Fareham | 2022 |
| KJF Plumbing Ltd | Halesowen | 2022 |
| KJP Recycling Ltd | Newcastle Upon Tyne | 2024 |