| 1st Degree Heating and Plumbing Services Ltd | Plumbing & heating | DL11 6BU | 2007 |
| 3 Wire Heating Ltd | Plumbing & heating | DL2 2AR | 2020 |
| 3 Wire Ltd | Electricians | DL2 2AR | 2007 |
| A & G Developments (Yorkshire) Ltd | Builders | DL10 6QH | 2002 |
| A.W. Moffitt (Joinery) Ltd | Joiners & carpenters | DL10 7DP | 2003 |
| A1 Environmental Services Ltd. | Groundworks & demolition | DL10 7RZ | 1996 |
| Acute Pest Solutions Ltd | Pest control | DL2 1DW | 2015 |
| Advantage Electrical Svcs Ltd | Electricians | DL10 4BN | 2026 |
| Ah Windtech Ltd | Builders | DL2 2ZF | 2026 |
| Ahl Commercials Ltd | Garages & mechanics | DL10 5NY | 2023 |
| Alpha Building Control Ltd | Builders | DL10 5HG | 2018 |
| Andrew Allum Joinery and Construction Ltd | Joiners & carpenters | DL11 7AZ | 2019 |
| Andy Whiteside Carpentry Ltd | Joiners & carpenters | DL10 4SX | 2023 |
| Anthony Johnson Construction Ltd | Builders | DL10 6DG | 2017 |
| Asnm Property Maintenance Ltd | Gardeners & landscapers | DL10 7BE | 2025 |
| At Electrical Services Ltd | Electricians | DL10 7NE | 2009 |
| B P Garage Services Ltd | Garages & mechanics | DL10 7JQ | 1997 |
| B W Building Ltd | Builders | DL10 5NY | 2026 |
| Bau Innenraum Ltd | Plumbing & heating | DL2 1RE | 2017 |
| Bba North East Ltd | Builders | DL2 2PT | 2024 |
| Bespoke Profiles Ltd | Builders | DL10 5NU | 2024 |
| Bespoke Skin and Aesthetics Ltd | Hair & beauty | DL2 2RY | 2026 |
| Bh Blinds & Shutters Ltd | Builders | DL2 1QR | 2024 |
| Bluespike Landscape Designs Ltd | Gardeners & landscapers | DL11 6LE | 2007 |
| Bowman Builders Ltd | Builders | DL10 4UD | 2006 |
| Brookes Hv Solutions Ltd | Electricians | DL2 2BQ | 2026 |
| Browson Design & Build Ltd | Joiners & carpenters | DL11 7HE | 2017 |
| Bsa Electrical Ltd | Electricians | DL10 4SQ | 2020 |
| C and S Tyres Ltd | Garages & mechanics | DL10 5NY | 1998 |
| C G Egan Ltd | Hair & beauty | DL2 2XD | 2024 |
| C R Brown Electrical Ltd | Electricians | DL10 7HN | 2017 |
| C&C Construction Consultants Ltd | Builders | DL2 1FE | 2024 |
| C:Tose Ltd | Painters & decorators | DL2 2PT | 2025 |
| Calton Group Ltd | Builders | DL11 7QT | 2018 |
| Calvert & Co Construction Ltd | Builders | DL11 6NE | 2026 |
| Calvert & Jenkinson Ltd | Builders | DL11 6NE | 2008 |
| Cherry Tree Home Improvements Ltd | Builders | DL2 1QZ | 2025 |
| Cherry Tree Landscaping Ltd | Gardeners & landscapers | DL2 1QZ | 2022 |
| Chloe Roddam Ltd | Hair & beauty | DL2 3EB | 2021 |
| Cm Door Services Ltd | Builders | DL2 2WS | 2025 |
| Cmh Decorators Ltd | Painters & decorators | DL2 2BF | 2025 |
| Cna Rigging and Lifting Solutions Ltd | Builders | DL2 1AX | 2026 |
| Complete Home Inspections Guaranteed Ltd | Builders | DL2 2FD | 2024 |
| Complete Roofs and Drives Ltd | Roofers | DL2 1RP | 2023 |
| Construction Project Management Consultants Ltd | Builders | DL10 5NY | 2000 |
| Country Living Stoves Ltd | Plumbing & heating | DL10 4JG | 2023 |
| Critical Power Installations Ltd | Electricians | DL10 4EA | 2022 |
| Csm Bolting Ltd | Builders | DL2 1GJ | 2025 |
| Ctc Marine Projects Ltd | Builders | DL11 6EL | 2021 |
| Custom Lvt Flooring Ltd | Flooring & tiling | DL11 6SP | 2023 |
| D B Site Services Ltd | Builders | DL2 2JS | 1998 |
| D Crozier Ltd | Builders | DL10 5BQ | 2012 |
| D Hodgetts Decorators Ltd | Painters & decorators | DL10 7DY | 2002 |
| D Knox Joinery Contractors Ltd | Joiners & carpenters | DL10 4QA | 2002 |
| D.M.S. Drylining Ltd | Plasterers | DL10 7BE | 2004 |
| Dales Garden Services Ltd | Gardeners & landscapers | DL11 7DU | 2002 |
| Darlington & Tees Blinds Ltd | Builders | DL2 2WB | 2026 |
| Darlington Roofing Contractors Ltd | Roofers | DL10 5NY | 2016 |
| Dashwood Electrical Services Ltd | Electricians | DL10 4PL | 2022 |
| Dave Kay Joinery Ltd | Joiners & carpenters | DL10 4SX | 2002 |
| Ddk Design Group Ltd | Builders | DL10 5NY | 2022 |
| Ddk Design Ltd | Builders | DL10 5NY | 2017 |
| Demi Nicole Aesthetics Ltd | Hair & beauty | DL2 1TY | 2025 |
| Design4 Ltd | Builders | DL2 2UF | 2019 |
| Diamond 4x4 Repairs Ltd | Garages & mechanics | DL2 3LQ | 2010 |
| Dkg Project Management Ltd | Builders | DL2 2FU | 2026 |
| Doggy Access Ltd | Builders | DL2 1LW | 2017 |
| Dollface World Ltd | Hair & beauty | DL10 4QY | 2021 |
| Douglas Gas Services Ltd | Plumbing & heating | DL10 5GZ | 2007 |
| Dovetail Joinery & Building Services Ltd | Joiners & carpenters | DL2 3NH | 2020 |
| Dsd Entrances Ltd | Joiners & carpenters | DL10 5NY | 2024 |
| Durham Tees Valley Windows, Doors and Conservatories Ltd | Glaziers | DL2 1RA | 2007 |
| Eastholme Commercials Ltd | Garages & mechanics | DL11 7RD | 2019 |
| Eastwood Tree Specialists Ltd | Gardeners & landscapers | DL10 4PS | 2025 |
| Ellis Builders Ltd | Builders | DL11 7HX | 2002 |
| Elm Integrated Services Ltd | Builders | DL2 2QY | 2016 |
| Emre Turkish Barber Ltd | Hair & beauty | DL10 4HZ | 2019 |
| Endeavour Electrical Engineering Ltd | Electricians | DL2 2SN | 2026 |
| Enhance Property Maintenance Specialists Ltd | Builders | DL10 7NE | 2003 |
| Esquire Barber Shop (Richmond) Ltd | Hair & beauty | DL10 4QG | 2014 |
| Eurojag Services Ltd | Garages & mechanics | DL2 1QH | 2020 |
| Eve Beauty Ltd | Hair & beauty | DL2 2FU | 2011 |
| Excellere Plumbing & Heating Ltd | Plumbing & heating | DL2 1AD | 2025 |
| F & E Trade Services Ltd | Builders | DL2 2ZL | 2025 |
| Fitting Property Solutions Ltd | Joiners & carpenters | DL2 1LE | 2020 |
| G & J Golding Ltd | Cleaners | DL10 4RW | 2004 |
| G.E.Brown & Son Ltd | Builders | DL11 6NH | 2006 |
| Gallowgate Motors Ltd | Garages & mechanics | DL10 4TE | 2005 |
| Garth Building and Joinery Ltd | Joiners & carpenters | DL10 5NY | 2026 |
| Gasgo Plumbing & Heating Ltd | Plumbing & heating | DL2 2AW | 2010 |
| Gavin Watson Plumbing & Heating Ltd | Plumbing & heating | DL2 1HF | 2017 |
| Gibsons Tiling Services Ltd | Flooring & tiling | DL10 4SX | 2011 |
| Gilmoor Communications Ltd | Groundworks & demolition | DL10 5NY | 2023 |
| Gmr Civils Ltd | Builders | DL10 7TY | 2017 |
| Gnat UK Ltd | Groundworks & demolition | DL10 4FB | 2005 |
| Goldielocks Training Academy Ltd | Hair & beauty | DL2 2GG | 2024 |
| Good Vibes Estates & Facilities Ltd Ltd | Electricians | DL2 2BU | 2026 |
| Graham Everett Rope Access Ltd | Builders | DL2 1HJ | 2014 |
| Graham Faulkner Building & Joinery Services Ltd | Builders | DL10 5NY | 2015 |
| Granite Rentals Ltd | Joiners & carpenters | DL2 2ZE | 2022 |
| Grove House Pest Control Ltd | Pest control | DL11 7QR | 2012 |
| Gsm Maintenance Solutions Ltd | Builders | DL2 3DE | 2017 |
| Gt Brickwork Services Ltd | Builders | DL10 7SB | 2018 |
| Gti Installation Ltd | Builders | DL2 2AT | 2023 |
| H. J. I'Anson Ltd | Groundworks & demolition | DL2 2UH | 2009 |
| Halo Corporate Holdings Ltd | Hair & beauty | DL2 2NY | 2023 |
| Halo Hair Group Darlington Ltd | Hair & beauty | DL2 2NY | 2007 |
| Halo Hair Group Durham Ltd | Hair & beauty | DL2 2NY | 2024 |
| Halo Hair Group Glasgow Ltd | Hair & beauty | DL2 2NY | 2024 |
| Halo Hair Group Reading Ltd | Hair & beauty | DL2 2NY | 2024 |
| Hambleton Steel Group Ltd | Builders | DL10 7JH | 2017 |
| Hambleton Steel Ltd | Builders | DL10 7JH | 1995 |
| Hammond Swimming Pools Ltd | Builders | DL11 7PW | 1998 |
| Harpers Construction & Groundworks Ltd | Builders | DL2 1JH | 2015 |
| Harvey Heating Ltd | Plumbing & heating | DL10 7LA | 2017 |
| Hd-Hv Ltd | Electricians | DL2 2BQ | 2026 |
| Heaven Scent Cleaning Services Ltd | Cleaners | DL10 7JW | 2014 |
| Heron Contracting Ltd | Electricians | DL10 7HB | 2005 |
| Heron Drive Ltd | Builders | DL11 7BL | 2016 |
| Highways Planning Consultancy Ltd | Builders | DL10 7RL | 2026 |
| Hippo Plumbing Ltd | Plumbing & heating | DL10 7RT | 2017 |
| His Hair Shop Ltd | Hair & beauty | DL10 4QA | 2002 |
| Hk Joinery and Tiling Ltd | Builders | DL10 6RE | 2023 |
| Hl Medical Aesthetics Ltd | Hair & beauty | DL2 1LG | 2022 |
| Holmedale Valley Developments Ltd | Builders | DL10 5DX | 2018 |
| Howard Timber (North East) Ltd | Builders | DL10 7JQ | 1976 |
| I Doughty Ltd | Plumbing & heating | DL10 7HQ | 2007 |
| Ian Walker & Sons Ltd | Builders | DL11 7RA | 2002 |
| Imaraworks Ltd | Builders | DL10 5LX | 2026 |
| Industrial Coatings North East Ltd | Builders | DL2 1UL | 2015 |
| Innishannon Developments Ltd | Builders | DL11 6UL | 2016 |
| Innovate Access Solutions Ltd | Builders | DL10 6HQ | 2020 |
| Inspired Interiors Design & Installation Ltd | Joiners & carpenters | DL10 6HN | 2014 |
| Integrated Polymer Systems (Northern) Ltd | Roofers | DL10 7JG | 2000 |
| Integrated Polymer Systems Ltd | Roofers | DL10 7JG | 1985 |
| Into Painting & Decorating Ltd | Painters & decorators | DL2 2ND | 2021 |
| Ips Roofing Ltd | Roofers | DL10 7JG | 2012 |
| Ips Waterproofing Ltd | Roofers | DL10 7JQ | 2025 |
| Izzy Rose Hair Ltd | Hair & beauty | DL10 7LD | 2022 |
| J Staley (Stonework) Ltd | Builders | DL10 4TG | 2002 |
| J W Ayre Joinery Ltd | Joiners & carpenters | DL10 7HQ | 2026 |
| J. Arkle Ltd | Builders | DL2 1UA | 2019 |
| J. M. Dale Ltd | Electricians | DL10 4PU | 2002 |
| J. R. Wilkinson & Sons Ltd | Builders | DL11 7ED | 2002 |
| J.L. Greenwood Ltd | Joiners & carpenters | DL11 6AF | 2019 |
| James Burke Joinery Ltd | Joiners & carpenters | DL10 4PW | 2016 |
| James Ford Ltd | Builders | DL10 6DA | 2015 |
| Janitorial Supplies Direct UK Ltd | Cleaners | DL10 5NY | 2018 |
| Jasmine Construction Ltd | Builders | DL11 7HS | 2025 |
| Jb Beauty (Richmond) Ltd | Hair & beauty | DL10 4DP | 2026 |