| Anton J. Benjamin Limited, | London | 1953 |
| Anton Kuzmin Consulting Limited | London | 2023 |
| Anton O’Donnell Productions Ltd | London | 2024 |
| Anton Potapov Games Ltd | London | 2024 |
| Anton Powers Ltd | Manchester | 2015 |
| Anton Services Limited | London | 2022 |
| Anton Short Editing Ltd | London | 2024 |
| Anton Supreme Ltd | Woolwich Dockyard | 2012 |
| Anton Trading Ltd | Ilford | 2019 |
| Anton Works Limited | London | 2022 |
| Anton&Eve Ltd | London | 2025 |
| Antonellam Ltd | London | 2016 |
| Antoni Karpouzas Limited | Banstead | 2013 |
| Antonia Enterprise Systems Limited | Milton Keynes | 2026 |
| Antonia Film Ltd | London | 2019 |
| Antonia Hinds Productions Ltd | London | 2023 |
| Antonia Lloyd Limited | Oxford | 2008 |
| Antonia Tasman Ltd | Peterborough | 2016 |
| Antonie Limited | London | 2025 |
| Antoniikk Media Ltd | Romford | 2023 |
| Antonine Technology Ltd | Glasgow | 2008 |
| Antonio Fernandes Online Courses Ltd | Swindon | 2020 |
| Antonio Neves Ltd | Wantage | 2017 |
| Antonio OFS Ltd. | London | 2020 |
| Antoniou Productions Ltd | Enfield | 2018 |
| Antonis Evmorfopoulos Limited | London | 2026 |
| Antonis IT Solutions Ltd | Oxford | 2015 |
| Antonius Consultancy Limited | Bolton | 2016 |
| Antonix Technologies Ltd | Isleworth | 2026 |
| Antony Etwell Limited | East Horsley | 2003 |
| Antony Howard Barron Limited | Nr Preston | 2021 |
| Antony James Limited | Whitstable | 2012 |
| Antony Knobbs IT Services Limited | Stamford | 2013 |
| Antony Neal Ltd | Boston | 2013 |
| Antony Slack Ltd | Edinburgh | 2008 |
| Antony TSE Ltd | New Malden | 2019 |
| Antonym Cloud Ltd | Accrington | 2024 |
| Antonym Games Ltd | Accrington | 2025 |
| Antoon Consulting Limited | Wateringbury | 2021 |
| Antopeto Ltd | Ashford | 2025 |
| Antoun, Ltd | Uxbridge | 2015 |
| Antournage Ltd | London | 2022 |
| Antraker Ltd | London | 2023 |
| Antreynolds Top Services Ltd | London | 2025 |
| Antrika Ltd | London | 2015 |
| Antrim Agricultural Society | Crumlin | 1960 |
| Antrim Ltd | Cheadle Hulme | 2017 |
| Antrio Ltd | Pontefract | 2026 |
| Antropy Ltd | Crawley | 2008 |
| Antrum Limited | London | 2001 |
| Ants Business Solutions Ltd | Wembley | 2023 |
| Ants Energy Ventures Ltd | London | 2026 |
| Ants Hill & Goose Limited | York | 2025 |
| Antscore Ltd | Kington | 2025 |
| Antser Group Limited | Birmingham | 2022 |
| Antshake Ltd | Sunderland | 2007 |
| Antstorm Ltd | Weybridge | 2022 |
| Antstream Limited | London | 2013 |
| Anttechcs Ltd | Crawley | 2023 |
| Antuar Limited | Newry | 2018 |
| Antubs Ltd | London | 2019 |
| Antumbra Ltd | Sittingbourne | 2026 |
| Antur Felin CYF | Machynlleth | 2026 |
| Antur Saas Labs Ltd | Cardiff | 2025 |
| Antvista Ltd | Sittingbourne | 2015 |
| Antware Limited | London | 2021 |
| Antwi Associates Limited | Surrey | 2005 |
| Antwi Systems Ltd | London | 2018 |
| Antwon Ltd | Southsea | 2020 |
| Antworks Technology Limited | Emsworth | 2020 |
| Antyx Animation (Phobes) Limited | Scunthorpe | 2009 |
| Antyx Ltd | Scunthorpe | 2011 |
| ANU Internet Services Limited | Bristol | 2005 |
| ANU Softech Ltd | Solihull | 2019 |
| ANU Software Solutions Ltd | Swindon | 2014 |
| ANU Sols Ltd | Watford | 2026 |
| Anuary Ltd | Hemel Hempstead | 2011 |
| Anub Ltd | London | 2025 |
| Anubis Film Productions Ltd | London | 2022 |
| Anubis Films Ltd | Preston | 2020 |
| Anubis Games Limited | Newport | 2023 |
| Anubis PS Ltd | Hasfield | 2025 |
| Anubis Software Ltd | Swansea | 2024 |
| Anubis Technology Ltd | Kelty | 2008 |
| Anubis Trading Limited | London | 2024 |
| Anubis Training Limited | Street | 2024 |
| Anugraha Consulting Ltd | London | 2016 |
| Anugraha Ventures Limited | Welling | 2015 |
| Anuhi-Ai Ltd | Ashford | 2025 |
| Anul Business Solutions Ltd | Swanscombe | 2022 |
| Anulog Power and Data Solutions Ltd | Milton Keynes | 2024 |
| Anuma Intelligence Ltd | Reading | 2025 |
| Anuma Limited | Reading | 2013 |
| Anuman Limited | London | 2011 |
| Anumana Limited | Wilmslow | 2021 |
| Anumula Software Developers Ltd | Cardiff | 2022 |
| Anunav Limited | High Wycombe | 2023 |
| Anuncia Limited | Leicester | 2015 |
| Anunnaki Research Ltd. | Stafford | 2022 |
| Anunnaki Technologies Limited | Manchester | 2024 |