| Acir Limited | Borehamwood | 2019 |
| Acis Business Services Limited | Hastings | 2001 |
| Acis Capital Limited | London | 2015 |
| Acis Limited | Scarborough | 1999 |
| Acis Travel Services Limited | | 1984 |
| ACJ Capital Limited | Birkenhead | 2022 |
| ACJ Communications Limited | Leigh On Sea | 2016 |
| ACJ Consultancy Limited | Ross-On-Wye | 2020 |
| ACJ Creative Limited | St. Albans | 2025 |
| ACJ Digital Accounts Ltd | Sandwich | 2024 |
| ACJ Engineering Limited | Lympne | 2021 |
| ACJ Finance Ltd | Croydon | 2023 |
| ACJ Mechanical Ltd | Chinnor | 2023 |
| ACJ Media Ltd | Swadlincote | 2021 |
| ACJ Norman & Co Ltd | London | 2025 |
| ACJ Optical Locum Services Limited | Ramsgate | 2026 |
| ACJ Reporting Ltd | Wigan | 2018 |
| ACJ Research Ltd | Wolverhampton | 2012 |
| Acj-Design (Scotland) Ltd | Elgin | 2016 |
| Acjecology Limited | West Mersea | 2014 |
| ACK (Holdings) Limited | Bolton | 2014 |
| ACK 2020 Ltd | Stalybridge | 2020 |
| ACK Accounting & Financial Services Limited | Gillingham | 2025 |
| ACK Advisory Limited | Manchester | 2020 |
| ACK Business Ltd | London | 2026 |
| ACK Lane Limited | Stockport | 2012 |
| ACK Management Limited | Belper | 2004 |
| ACK Marine Ltd | Southampton | 2026 |
| ACK Solutions Ltd | Horsham | 1999 |
| ACK Technical Services Ltd | Prenton | 2020 |
| Ackai. Ltd | London | 2025 |
| Ackc Animal Services Ltd | Eton | 2017 |
| Ackc Ltd | Warrington | 2010 |
| Acker Coaching Ltd | Cambridge | 2022 |
| Ackerley & Associates Limited | Harrogate | 2006 |
| Ackerman Advisors Ltd | London | 2017 |
| Ackers Consulting Engineers Ltd | Leicester | 2020 |
| Ackers P Investment Company Limited | Otley Road | 1982 |
| Ackha Limited | Slough | 2024 |
| Acklam Bond Limited | Accrington | 2016 |
| Acklam Consulting Limited | Bristol | 2007 |
| Acklam Hall Management Ltd | South Shields | 2014 |
| Acklam Russett Ltd. | Goole | 2018 |
| Ackland Contracting Limited | London | 2024 |
| Ackland Hill Papenfus Solicitors Limited | Exeter | 2012 |
| Ackland Law Limited | Cardiff | 2021 |
| Ackland Mainwaring Limited | Monmouth | 2011 |
| Ackland Webb Limited | Faversham | 2011 |
| Ackley MA LEE & Co Ltd | Wembley | 2019 |
| Ackley Mally Ltd | London | 2021 |
| Ackman Architecture + Design Ltd | London | 2008 |
| Ackor Ltd | Chorley | 2026 |
| Ackraceeproofreading Ltd | Northampton | 2025 |
| Ackreditering Service for Conformity Assessment Bodies Limited | East Ham London | 2020 |
| Ackroyd Community Association | London | 2002 |
| Ackroyd Engineering Limited | Stockton-On-Tees | 2025 |
| Ackroyd Interpreting Limited | Scarborough | 2025 |
| Ackroyd Lowrie Limited | London | 2014 |
| Ackroyd Willoughby Paintings Conservation Ltd | London | 2014 |
| Ackroyds (Accountancy & Taxation Services) Ltd | Halifax | 2012 |
| Acksion Ltd | Milton Keynes | 2026 |
| Acksys Limited | Bradford | 2015 |
| Ackura Accounting & Consulting Ltd | London | 2025 |
| ACL & Co (London) Ltd | Thornton Heath | 2022 |
| ACL 2014 Holdings Limited | Watford | 2014 |
| ACL Capital Limited | Epsom | 2009 |
| ACL Commercial Services Limited | Aberdare | 2024 |
| ACL Contract Solutions Ltd | Colchester | 2025 |
| ACL Education Solutions Limited | London | 2021 |
| ACL Financial Solutions Limited | Wakefield | 2013 |
| ACL Gilchrist Ltd | Nottingham | 2020 |
| ACL Graphic Installations Ltd | Leigh-On-Sea | 2015 |
| ACL Grinding Services Ltd | Nuneaton | 2017 |
| ACL Horizons Limited | Solihull | 2025 |
| ACL Impact Limited | Sevenoaks | 2019 |
| ACL IT Solution Limited | London | 2014 |
| ACL Procurement Ltd | Bolton | 2020 |
| ACL Property Services Limited | Twickenham | 2021 |
| ACL Proposal Solutions Limited | Worcester | 2019 |
| ACL Refrigeration & AC Ltd | London | 2024 |
| ACL Sheet Metal Ltd | Leicester | 2003 |
| Acl.Man.Eng.Services Ltd | Craigavon | 2022 |
| ACL23 Ltd | Lossiemouth | 2023 |
| Acla Limited | Marlborough | 2009 |
| Acla Trading Ltd | Basingstoke | 2024 |
| Aclad FM Consultancy Ltd | Ashford | 2019 |
| Acland Advisers Limited | London | 2024 |
| Acland Legal Consultants Limited | London | 2019 |
| Aclarius Limited | Aylesbury | 2020 |
| Aclass Accountancy Services Limited | Tideford | 2018 |
| Aclaí Ltd | London | 2025 |
| Acld Marketing Ltd | Wirral | 2020 |
| Acle Ltd | Stoke-On-Trent | 2024 |
| ACLER8 Ltd | Hatfield | 2025 |
| Aclg Consulting Management Limited | Altrincham | 2012 |
| Aclha Ltd. | London | 2022 |
| Aclind Limited | Tadley | 1982 |
| Aclipse Consultants Limited | Staffordshire | 2003 |
| Acloris Ltd | Wigan | 2026 |
| Aclrath Capital Limited | Leigh On Sea | 2024 |