| A1 Zero Carbon Ltd | Builders | CF48 2SR | 2024 |
| Ace Property Investments Ltd | Builders | CF48 3SS | 2006 |
| Acn Construction Ltd | Builders | CF44 9EH | 2023 |
| Adfercymru Ltd | Builders | CF48 4QA | 2021 |
| Adk Drylining Ltd | Builders | CF44 6UW | 2026 |
| All Sealants Ltd | Builders | CF44 9JE | 2015 |
| Amber & Ruby Developments Ltd | Builders | CF48 2SR | 2017 |
| Beacons Group Ltd | Builders | CF48 2SR | 2024 |
| Bedrooms, Kitchens and Bathrooms Ltd | Builders | CF44 8LE | 2015 |
| Bhl Fix Ltd | Builders | CF44 8BZ | 2026 |
| Breconshire Construction Ltd | Builders | CF48 2EE | 2013 |
| Brennan Design & Developments Ltd | Builders | CF44 0DB | 2023 |
| Brickfitz Ltd | Builders | CF48 4SZ | 2024 |
| Building Neads Ltd | Builders | CF44 6DU | 2005 |
| C & C Wood Ltd | Builders | CF44 9YU | 2021 |
| C3 Construction Services Ltd | Builders | CF48 2DN | 2018 |
| Capricorn Windows Ltd | Builders | CF44 8RN | 2003 |
| Celtic Damproofing Ltd | Builders | CF44 0ED | 2001 |
| Cheeke Jones Building Services Ltd | Builders | CF48 2EB | 2025 |
| Chris Evans Building Contractors Ltd | Builders | CF44 0YS | 2011 |
| Chris Tasker Construction Ltd | Builders | CF48 4LT | 2025 |
| Cjc Estates Ltd | Builders | CF44 0EZ | 2012 |
| Cjc Plant Hire Ltd | Builders | CF44 0EZ | 2026 |
| Clad9 Ltd | Builders | CF44 6TP | 2023 |
| Cld Builders Ltd | Builders | CF48 2TN | 2026 |
| Clm Windows & Doors Ltd | Builders | CF44 8DN | 2020 |
| Cocosteli Construction Ltd | Builders | CF48 3SN | 2025 |
| Cpa Construction Services Ltd | Builders | CF48 1RA | 2026 |
| Cva Building Ltd | Builders | CF44 6SN | 2007 |
| Cynon Contract Services Ltd | Builders | CF44 0SG | 2023 |
| D M Caviell Services Ltd | Builders | CF44 0RQ | 2018 |
| D&A Carpentry Specialist Ltd | Builders | CF44 0AJ | 2003 |
| D&A Connections Ltd | Builders | CF44 9AW | 2018 |
| Dare Building Services Ltd | Builders | CF44 6NF | 2025 |
| Dca Construction Ltd | Builders | CF44 9DG | 2026 |
| Ddsk Developments Ltd | Builders | CF48 4TQ | 2019 |
| Dgd Civils Ltd | Builders | CF44 9DS | 2022 |
| Dizzy Heights Access Solutions Ltd | Builders | CF48 2SR | 2014 |
| Dlm Groundwork Contractors Ltd | Builders | CF48 4PU | 2025 |
| Door Centre South Wales Ltd | Builders | CF48 2TN | 2025 |
| Drec Building Ltd | Builders | CF48 4EX | 2014 |
| Ecas Group Ltd | Builders | CF48 2PG | 2025 |
| Eco Building Compliance UK Ltd | Builders | CF48 1BW | 2023 |
| Elite Vinyl Wraps Ltd | Builders | CF48 2TN | 2026 |
| Envision Contractors Ltd | Builders | CF48 2AU | 2023 |
| Ers Networks Ltd | Builders | CF44 6BF | 2025 |
| Eurotech Balcony Systems Ltd | Builders | CF44 9UP | 2018 |
| Evagrass Ltd | Builders | CF44 6DA | 2021 |
| Ezirend Ltd | Builders | CF44 7LR | 2017 |
| Fear & Law Properties Ltd | Builders | CF48 3HF | 2024 |
| Ffrind Developments Ltd | Builders | CF48 4TQ | 2016 |
| Flec Construction Ltd | Builders | CF48 4QP | 2026 |
| Fletcher Groundworks & Civils Ltd | Builders | CF44 6DQ | 2026 |
| Full Moon (Aberaman) Ltd | Builders | CF44 8EZ | 2024 |
| G Caswell Services Ltd | Builders | CF48 3LD | 2018 |
| G Curtis Rail Ltd | Builders | CF48 1TW | 2017 |
| Gap Internals Ltd | Builders | CF44 8BZ | 2015 |
| Gce Engineering Ltd | Builders | CF44 6TX | 2014 |
| Gdj Construction Management and Property Maintenance Ltd | Builders | CF44 6RE | 2025 |
| Gerwyn Davies & Daughter Ltd | Builders | CF48 2ER | 2024 |
| Giles & Sons Rail Ltd | Builders | CF48 2ED | 2016 |
| Gp Tech and Small Assets Ltd | Builders | CF44 7LD | 2024 |
| Gth Consrtuction (Wales) Ltd | Builders | CF48 1BS | 2014 |
| Hareva Construction Ltd | Builders | CF48 2SR | 2019 |
| Home & Dry (Merthyr Tydfil) Ltd | Builders | CF48 2SR | 2007 |
| Integrated Fencing Ltd | Builders | CF44 8DL | 2020 |
| Integrated Rail Fencing Ltd | Builders | CF44 8DL | 2021 |
| J E Management Ltd | Builders | CF48 2RW | 2016 |
| Jce Maintenance Ltd | Builders | CF44 9BS | 2022 |
| Jgh Construction Solutions Ltd | Builders | CF48 4PH | 2026 |
| Jodan Contracts Ltd | Builders | CF48 2SR | 2015 |
| Jones Building Ltd | Builders | CF48 4JA | 2017 |
| Jordan Pryor Carpentry Ltd | Builders | CF44 8DW | 2024 |
| K & H Groundworks Ltd | Builders | CF44 0AG | 1998 |
| K.C Groundworks & Civils Ltd | Builders | CF48 1JN | 2021 |
| Kad Design Projects Ltd | Builders | CF44 9HR | 2007 |
| Karaway Windows & Doors Ltd | Builders | CF44 0LA | 2022 |
| Kelray Ltd | Builders | CF48 4DR | 1998 |
| Launch Fly Capture Technologies Ltd | Builders | CF48 2NU | 2018 |
| Laystone Construction Ltd | Builders | CF48 4LT | 2017 |
| Lewis Falkiner Properties Ltd | Builders | CF48 3TD | 2016 |
| Lightweight Roofing & Building Solutions Ltd | Builders | CF48 1TJ | 2019 |
| Llc Services Ltd | Builders | CF48 4TQ | 2019 |
| Loft Pro Cardiff Ltd | Builders | CF44 8EZ | 2014 |
| Logantroyrail Ltd | Builders | CF48 4DJ | 2024 |
| Louwis Groundworks Ltd | Builders | CF48 1LN | 2018 |
| Lrm Maintenance and Construction Ltd | Builders | CF48 3RR | 2019 |
| Luke Dummett Bricklaying Ltd | Builders | CF48 1RZ | 2016 |
| Luxury Home Improvements Ltd | Builders | CF44 8RS | 2015 |
| Lw Housing Refurbishments Ltd | Builders | CF48 2DW | 2018 |
| M & S Roller Shutter Doors Ltd | Builders | CF48 2SR | 2008 |
| M Colcombe Interiors Ltd | Builders | CF44 0BU | 2011 |
| M Higgins Services Ltd | Builders | CF48 1SB | 2019 |
| M Morgan Maintenance & Building Ltd | Builders | CF44 8NT | 2021 |
| M W Barry Ltd | Builders | CF48 2TN | 2026 |
| M Williams Building & Plastering Ltd | Builders | CF44 0US | 2025 |
| M. Delacey & Sons (Holdings) Ltd | Builders | CF48 3TD | 1994 |
| M.E.R.S. Holdings Ltd | Builders | CF48 1RY | 2022 |
| Maintenance Matters Merthyr Ltd | Builders | CF48 2SR | 2026 |
| Matcon Civil Engineering Ltd | Builders | CF48 4NL | 2010 |
| Matcon Plant Ltd | Builders | CF48 4NL | 2021 |
| Mattix Installations Ltd | Builders | CF44 8BL | 2025 |
| Mgr Civils Ltd | Builders | CF48 1SP | 2020 |
| Mike Evans Building & Plastering Contractors Ltd | Builders | CF44 9LG | 2012 |
| Millennial Groundworks Ltd | Builders | CF48 2DS | 2022 |
| Minerva Construction (UK) Ltd | Builders | CF48 3NY | 2017 |
| Mj 93 Construction Ltd | Builders | CF48 2DH | 2019 |
| Mj Property Maintenance Services Ltd | Builders | CF44 8PP | 2025 |
| Mlc Gardens Ltd | Builders | CF44 6DQ | 2020 |
| Morgan Rendering and Plastering Ltd | Builders | CF44 0RT | 2023 |
| Mp Jones Property Ltd | Builders | CF44 8UH | 2023 |
| Mrg Lofts and Construction Ltd | Builders | CF44 0HW | 2026 |
| Msw Property Developments Ltd | Builders | CF48 4DR | 2024 |
| Mww Property Renovation Ltd | Builders | CF44 0DS | 2025 |
| Mya Lee Services Ltd | Builders | CF44 7HH | 2018 |
| N Dudley Services Ltd | Builders | CF48 3LA | 2019 |
| N.Bsealant’S Ltd | Builders | CF44 8NR | 2026 |
| Nk. Hughes. Construction Ltd | Builders | CF44 0NX | 2026 |
| Notchface Ltd | Builders | CF44 0AE | 1987 |
| Oakwell Kitchens Ltd | Builders | CF44 8RA | 2024 |
| Oakwell Masonry Services Ltd | Builders | CF44 8RA | 2017 |
| Oz Tech Services Ltd | Builders | CF48 2PS | 2018 |
| P & C Building & Management Solutions Ltd | Builders | CF48 2SR | 2016 |
| P Hawkes Construction Ltd | Builders | CF44 0NH | 2015 |
| P. Morgan Plant Hire & Civil Engineering Ltd | Builders | CF44 9YS | 1997 |
| Parker & Son Construction Ltd | Builders | CF44 6RA | 2004 |
| Pearce Construction & Developments Ltd | Builders | CF44 0TS | 2023 |
| Philips Construction Ltd | Builders | CF44 0HU | 2024 |
| Phoenix Fencing & Construction Ltd | Builders | CF48 4DR | 2021 |
| Platinum Carpentry & Roofing Ltd | Builders | CF48 3TD | 2025 |
| Precision Land Surveyors (Wales) Ltd | Builders | CF44 9YY | 2024 |
| Prestige Homes Llwydcoed School Ltd | Builders | CF44 0EZ | 2022 |
| Price Fencing & Landscaping Ltd | Builders | CF48 2SD | 2002 |
| Price Fencing Management Ltd | Builders | CF48 2SD | 2014 |
| Price Home Developments Ltd | Builders | CF48 1BB | 2023 |
| Price Pro-Construct Ltd | Builders | CF48 1BB | 2020 |
| Primo Av Ltd | Builders | CF44 6AA | 2019 |
| Pritchard Commercial Services Ltd | Builders | CF44 9UP | 2024 |
| Propec Group Ltd | Builders | CF44 7NL | 2025 |
| Qdl Contractors Ltd | Builders | CF48 4DR | 2007 |
| R. Chappell Groundworks Ltd | Builders | CF44 0LR | 2005 |
| Rd Construction & Maintenance Ltd | Builders | CF48 4DR | 2018 |
| Rgj Building Services Ltd | Builders | CF48 1NJ | 2015 |
| Rhys Thomas Property Maintenance Ltd | Builders | CF44 6SR | 2025 |
| Rici Ltd | Builders | CF48 4HE | 2019 |
| Ridgestone Construction Ltd. | Builders | CF48 4RG | 2012 |
| Ryan Williams Brawn Foundations Ltd | Builders | CF44 6SG | 2025 |
| S & R Carpentry & Building Ltd | Builders | CF48 3HG | 2008 |
| S R Building Solutions Ltd | Builders | CF48 2SR | 2007 |
| S Williams Electrical Services Ltd | Builders | CF48 1RE | 2026 |