| 528 Developments Limited | Walsall | 2024 |
| 52HWD Ltd | Pinner | 2025 |
| 52WEYSIDE Road Ltd | Marlow | 2024 |
| 53 Degrees N Ltd | Liverpool | 2025 |
| 53 Egerton Crescent Ltd | London | 2025 |
| 53 Land Limited | Maidstone | 2025 |
| 53 the Convent Ltd | Maidstone | 2025 |
| 53 the Garden House Ltd | Maidstone | 2025 |
| 53 Warrington Group Ltd | London | 2026 |
| 53/55 Zetland Road Limited | Hyde | 2015 |
| 534 Build Ltd | Reading | 2024 |
| 5381 Ltd | Grays | 2018 |
| 53DEGREES North (Projects) Limited | Leeds | 2013 |
| 54 Camberwell Green Limited | London | 2016 |
| 54 Holloway Road Limited | London | 2015 |
| 54 One Property Ltd | Hartlepool | 2016 |
| 54 Porchester Place Limited | London | 2017 |
| 540 Ltd | Meopham | 2025 |
| 540 Wilbraham Road Limited | Hyde | 2020 |
| 541 Electrical Limited | London | 2025 |
| 546 Developments Ltd | London | 2018 |
| 547 Barlow Moor Road Limited | Hyde | 2013 |
| 55 Construction Ltd | London | 2015 |
| 55 CWW Ltd | London | 2022 |
| 55 Degree Developments Ltd | Morpeth | 2025 |
| 55 Degrees North East Limited | North Shields | 2021 |
| 55 Developments Ltd | Glasgow | 2026 |
| 55 Manchester Road (Altrincham) Limited | Altrincham | 2021 |
| 55 Old Broad Street Developer Limited | London | 2001 |
| 55 Richfield Road Ltd | Borehamwood | 2026 |
| 55 West Ltd | Frome | 2024 |
| 554 BYA Ltd | London | 2023 |
| 5555 Ltd | Matlock | 2023 |
| 5557 TBR Limited | Tunbridge Wells | 2015 |
| 555PLUMING&HEATINGSERVICES Ltd | Leicester | 2024 |
| 55TWO Holdings Ltd | Dunstable | 2023 |
| 55WC Limited | London | 2023 |
| 56 (2015) Ltd | Edinburgh | 2015 |
| 56 Construction Limited | Addlestone | 2021 |
| 56 Unicorns Ltd | London | 2024 |
| 56-58 Central Parade Limited | Canterbury | 2020 |
| 56-66 Dorchester Road Management Limited | Ringwood | 2019 |
| 56103 Limited | Blackburn | 2022 |
| 565 Kingston Limited | London | 2024 |
| 57 Developments Limited | Frodsham | 2019 |
| 57 Helix Road (London) Limited | London | 2007 |
| 57 Homes Limited | Yeovil | 2018 |
| 57 Renewables Ltd | Doncaster | 2023 |
| 57 Rutland Street Limited | London | 2015 |
| 57-59 High Lane Limited | Hyde | 2015 |
| 574 Group Limited | North Shields | 2025 |
| 574 Property Limited | North Shields | 2025 |
| 575 Finchley Road Limited | Elstree, Borehamwood | 1982 |
| 57D Developments Limited | Northwood | 2014 |
| 58 HS Ltd | London | 2025 |
| 58 Woodgrange Road Limited | London | 2020 |
| 58 Woodlands Road Limited | Epsom | 2022 |
| 583 Fishponds Road Management Company Limited | Wiltshire | 2005 |
| 59 Eaglesfield Road Limited | Staines-Upon-Thames | 2024 |
| 59 Upper Chorlton Road Limited | Hyde | 2021 |
| 59-60 Belsize Park Limited | London | 2019 |
| 5911 Barber Limited | Hayes | 2025 |
| 5911 Builders Ltd | Coventry | 2021 |
| 592 Interiors Limited | St Neots | 2025 |
| 59JH Construction Limited | Liskeard | 2024 |
| 5A Construction (UK) Ltd | Kingston Upon Thames | 2019 |
| 5AAB Services Ltd | Southall | 2025 |
| 5AB Limited | Windsor | 2022 |
| 5ALLY Ltd | Barnet | 2019 |
| 5B Group Limited | Birmingham | 2025 |
| 5B Projects Limited | Manchester | 2024 |
| 5B Properties (Leicester) Ltd | Leicester | 2019 |
| 5BB Sloan Limited | Tunbridge Wells | 2024 |
| 5BGS Limited | Market Harborough | 2020 |
| 5C Construction Ltd | Newry | 2018 |
| 5C Property Developers Ltd | Warrington | 2026 |
| 5C Scaffolding Ltd | Gillingham | 2017 |
| 5CPG Limited | Tunbridge Wells | 2017 |
| 5CT Limited | London | 2023 |
| 5D Civil Engineering Ltd. | Balsall Common | 2016 |
| 5D Construction (SW) Ltd | Plymouth | 2017 |
| 5D Construction Ltd | Peterborough | 2024 |
| 5D Electrical Contracts Ltd | Blackpool | 2026 |
| 5D Joinery Limited | Halstead | 2016 |
| 5D Projects Design and Build Ltd | Derby | 2023 |
| 5D Property and Facilities Services Ltd | London | 2022 |
| 5D Retail Ltd | Plymouth | 2025 |
| 5D Solutions (Brooklands) Ltd | Plymouth | 2023 |
| 5D Solutions (Holdings) Ltd | Plymouth | 2022 |
| 5D Solutions (Newton) Ltd | Plymouth | 2023 |
| 5D Solutions (SW) Ltd | Manchester | 2015 |
| 5D UK Operations Ltd | Hayes | 2020 |
| 5DB Ltd | Cardiff | 2017 |
| 5DBUILDING Ltd | Dunfermline | 2020 |
| 5DCARPENTRY Ltd | Burgess Hill | 2019 |
| 5DD Limited | Sutton | 2025 |
| 5DIAMOND Services Ltd | Blackburn | 2025 |
| 5F Travel Ltd | Macmerry | 2019 |
| 5G Fibre Comms Ltd | Sunderland | 2024 |
| 5G Personnel Recruitment Ltd | Southport | 2022 |