| Anticyclone Systems Limited | Hayling Island | 1998 |
| Antidote Agency Limited | London | 2019 |
| Antidote Arts Ltd | London | 2025 |
| Antidote Hospitality Ltd | Cranbrook | 2024 |
| Antidote Limited | London | 2003 |
| Antidote Projects Ltd | Chippenham | 2014 |
| Antifragile Enterprises Ltd | Lichfield | 2021 |
| Antifragile Structures Ltd | Wirral | 2024 |
| Antifragile Systems Limited | Bristol | 2019 |
| Antigenera Ltd | Belfast | 2026 |
| Antigenesis Biologics Ltd | Downpatrick | 2024 |
| Antigenika Ltd | Stokenchurch | 2024 |
| Antigonie Biosciences Ltd | York | 2025 |
| Antigrade Ltd | London | 2024 |
| Antigravity Ltd | Bury St. Edmunds | 2021 |
| Antigua Limited | London | 2011 |
| Antigua NO.3 Limited | Mediacityuk | 2020 |
| Antiguan New Wave Ltd | London | 2025 |
| Antika Culture and Diaspora CIC | London | 2022 |
| Antikor Biopharma Limited | London | 2001 |
| Antilles Bay Ltd | New Malden | 2021 |
| Antilles Commercial Enterprises Ltd | Brockenhurst | 2020 |
| Antillon Capital Ltd | Lincoln | 2024 |
| Antimark Limited | London | 2003 |
| Antimas Cleaning Ltd | Huntingdon | 2014 |
| Antimatter Studio Limited | London | 2026 |
| Antimicrobial Discovery Solutions Limited | Warwick | 2015 |
| Antimicrobial Focus Ltd | Sawbridgeworth | 2022 |
| Antimony Ltd | Borehamwood | 2018 |
| Antine Financial Solutions Limited | Herstmonceux | 2025 |
| Antini Enterprises Ltd | London | 2015 |
| Antinous Advisory Limited | Islington | 2024 |
| Antiochia Consulting Ltd | London | 2019 |
| Antiokheia Consultancy Ltd | London | 2022 |
| Antiope Management Limited | Harrogate | 2020 |
| Antios Multi-Concepts UK Ltd | Dartford | 2022 |
| Antiphonal Limited | London | 2005 |
| Antipocal Limited | Axbridge | 2021 |
| Antipodean Action Ltd | Faversham | 2015 |
| Antipodean Group Limited | London | 2025 |
| Antipodean Ventures Limited | London | 2024 |
| Antipodes Consulting Ltd | London | 2024 |
| Antiquarian Ltd | London | 2020 |
| Antiquarian Photographer Ltd | London | 2022 |
| Antique Buildings Limited | Surrey | 1983 |
| Antique Telephones Limited | Chislehurst | 2006 |
| Antiques Holdings Ltd | Darlington | 2026 |
| Antiques.Co.Uk Limited | London | 1999 |
| Antisana Ltd | London | 2019 |
| Antischool Limited | London | 2021 |
| Antisco Limited | London | 2005 |
| Antiva Ltd | Bedford | 2018 |
| Antiverse Ltd | Cardiff | 2017 |
| Antizar Advisory Ltd | Market Rasen | 2026 |
| Antjoule Consulting Ltd | London | 2025 |
| Antler Agency Limited | Chichester | 2017 |
| Antler Associates Ltd | London | 2016 |
| Antler BIO (UK) Limited | Cambridge | 2017 |
| Antler Consultancy Limited | Welwyn | 2025 |
| Antler Consulting (Hertford) Ltd | Hertford | 2022 |
| Antler Creek Ltd | London | 2017 |
| Antler Global Limited | London | 2019 |
| Antler Incorporated Ltd | Dartford | 2022 |
| Antler Innovation UK Limited | London | 2018 |
| Antler Marketing Ltd | Inverness | 2021 |
| Antler New Homes Limited | Bagshot | 2009 |
| Antler Property Corporation Limited | London | 1994 |
| Antler Social Ltd | Woking | 2021 |
| Antler Wealth Management Ltd | London | 2016 |
| Antlergold Limited | Teddington | 2020 |
| Antlers Management Ltd | Teddington | 2012 |
| Antleshow Contracting Limited | Warrington | 2013 |
| Antlia Wealth Hub UK Ltd | London | 2023 |
| Antlion Credit Consulting Ltd | Nottingham | 2023 |
| Antlion Limited | Lightwater | 2014 |
| Antlow Enterprises Limited | London | 1988 |
| Antmary 1 Ltd | Oldbury | 2026 |
| Antmet Solutions Limited | Newport | 2018 |
| Antnic Limited | Durham | 2006 |
| Anto Group Ltd. | London | 2019 |
| Anto Technology Ltd. | London | 2019 |
| Antoc Limited | Stratford Upon Avon | 2010 |
| Antograma Ltd | London | 2018 |
| Antoine Barker Consulting Solutions Ltd | Bridport | 2021 |
| Antoine Catteau Consulting Ltd | London | 2018 |
| Antoine Consulting Limited | Brighton | 2018 |
| Antoine Health Care Ltd | London | 2015 |
| Antoine Melon Hospitality Consulting Ltd | London | 2020 |
| Antoine Productions Limited | Cheshunt | 2017 |
| Antoine West Associates Limited | Twickenham | 2009 |
| Antoinette Antoine Live Ltd | East Tilbury | 2025 |
| Antoinette Oglethorpe Limited | Olney | 2012 |
| Antomad Ltd | Cambridge | 2020 |
| Anton Alfy Ltd | London | 2019 |
| Anton Burmistrov Limited | Poole | 2019 |
| Anton Buyers Ltd | Worthing | 2026 |
| Anton Clarke Ltd | Wimborne | 2016 |
| Anton Colella Advisory Limited | London | 2026 |
| Anton Corp Limited | London | 2008 |
| Anton Dell Limited | Penryn | 2014 |