| A Clarke Commercial Services Limited | Brentwood | 2017 |
| A Class Composites Ltd | Mildenhall | 2022 |
| A Clean Start Ltd | Peterculter | 2007 |
| A Clegg Autos Ltd | Blackburn | 2022 |
| A Closer Path Ltd | Halifax | 2025 |
| A Coles Ltd | Tiverton | 2007 |
| A Colin Lunn (Tobacconist) Limited | Cambridge | 2015 |
| A Coll Limited | Glasgow | 2013 |
| A Collection of Pixels Ltd | London | 2025 |
| A Collective (SW London) CIC | South Croydon | 2023 |
| A Colloff Limited | Orpington | 2017 |
| A Collyer Consulting Ltd | London | 2020 |
| A Colvin Consultancy Limited | Hickstead | 2016 |
| A Common Endeavour Ltd | London | 2018 |
| A Common Purpose Ltd | London | 2021 |
| A Common Thread Limited | London | 2020 |
| A Comms Culture Limited | Crewe | 2024 |
| A Company of Wild Things Limited | London | 2016 |
| A Connected Future Limited | London | 2015 |
| A Considered Curiosity Ltd | London | 2026 |
| A Consultancy Limited | London | 2002 |
| A Consultancy Services Limited | Manchester | 2015 |
| A Consultation Ltd | Rochdale | 2024 |
| A Consulting Ltd | Reading | 2022 |
| A Cooper Group Limited | Waterlooville | 1988 |
| A Cosma Limited | Uxbridge | 2008 |
| A Counts (SW) Limited | Liskeard | 2010 |
| A Couple of Birds Design Ltd | London | 2023 |
| A Craig Media Ltd | Bournemouth | 2015 |
| A Creative Endeavour Ltd | London | 2023 |
| A Creative Haus Ltd | Northampton | 2025 |
| A Critical Friend Limited | Penarth | 2013 |
| A Cromarty Engineering Ltd | Kirkwall | 2018 |
| A Cube Concepts Limited | Kenley | 2012 |
| A Cube TIC Limited | Bristol | 2021 |
| A Cubed Associates Ltd | London | 2023 |
| A Cubed Consulting Limited | Sutton | 2014 |
| A Culture of Kindness Ltd | Sturminster Newton | 2023 |
| A CUP of Tea Ltd | Cardiff | 2017 |
| A Curious Business Ltd | London | 2017 |
| A Curious Group of Hotels (UK) Limited | London | 2005 |
| A Curious Human Ltd | Hove | 2022 |
| A Curious Idiot Ltd | Horsham | 2023 |
| A Curtis Consultancy Ltd | Cardiff | 2020 |
| A D & C Manufacturing Limited | Birmingham | 2001 |
| A D & D Limited | Bradford | 2024 |
| A D & L Media Ltd | Portsmouth | 2026 |
| A D (Cumbria) Limited | Cumbria | 2002 |
| A D Accountancy Ltd | Pinner | 2017 |
| A D Accounting Limited | Reigate | 2013 |
| A D Accounts (Trusts) Limited | Hereford | 2020 |
| A D Accounts Limited | Hereford | 2019 |
| A D Architectural Design Consultants Limited | Crymych | 1991 |
| A D Assemblies Ltd | Sheffield | 2011 |
| A D Bell Group Limited | Harrogate | 2005 |
| A D Blackburn Ltd | London | 2020 |
| A D Bookkeeping & Payroll Services Ltd | Doncaster | 2017 |
| A D C (UK) Ltd. | Wisbech | 1996 |
| A D CAD Ltd | Stockton-On-Tees | 2015 |
| A D Catering Consultants Limited | Stafford | 2003 |
| A D Consulting (ADC) Limited | Warwick | 2016 |
| A D Consulting (Darwen) Limited | Milnthorpe | 2015 |
| A D Coombes Ltd | Wellington | 2023 |
| A D Doshi & Co Ltd | Leicester | 2016 |
| A D E Fire Services Limited | Bedford | 2003 |
| A D E Systems Limited | Chorley | 1992 |
| A D Engineering Design Ltd | Northampton | 2008 |
| A D Event Management Limited | Farnham | 2023 |
| A D Food Holdings Limited | Colchester | 2006 |
| A D Gasworks Limited | Warrington | 2016 |
| A D Greenfield Consulting Limited | Nottingham | 2018 |
| A D H London Limited | Chelmsford | 2014 |
| A D Humphrey Services Ltd | Bolton | 2022 |
| A D Hunt Limited | Swindon | 2009 |
| A D I Projects Limited | Kings Norton Birmingham | 2000 |
| A D Lunan Ltd | Wellingborough | 2026 |
| A D M Business Services Limited | Middlesex | 2004 |
| A D M Surveying Services Limited | Banstead | 2014 |
| A D Marston Ltd | Ibstock | 2023 |
| A D Mcmillan Associates Limited | Wiltshire | 2007 |
| A D Murphy Limited | Bushey | 2022 |
| A D Palfreyman Accountancy & Taxation Services Ltd | Bewdley | 2012 |
| A D Parsons Ltd | Stourbridge | 2019 |
| A D Patel & Co Ltd | London | 2005 |
| A D Pegg Limited | Telford | 2013 |
| A D Plans Limited | Lanark | 2004 |
| A D R Design Ltd | Kilsyth | 2007 |
| A D Research & Analysis Limited | Bristol | 2006 |
| A D Salmon Consultancy Ltd | Harrow | 2022 |
| A D Stuart & Co. Limited | Edinburgh | 2014 |
| A D Taplin Ltd | Bournemouth | 2025 |
| A D Taylor Limited | Gloucester | 2002 |
| A D V Accountancy Limited | Tonypandy | 2009 |
| A D W Services Limited | Mansfield | 2021 |
| A D Wardle Ltd | London | 2015 |
| A D Williams & Co Ltd | Morden | 2014 |
| A D Williams Employee Ownership Trustee Limited | Callington | 2020 |
| A D!Srupt!Ve !Influence! Limited | Stockport | 2014 |
| A Dabbler's Jaakpot Limited | Sale | 2017 |
| A Dagia Group Ltd | Leicester | 2026 |