| Altrincham Interiors Ltd | Altrincham | 2021 |
| Altrincham Town Centre Plan Limited | Warrington | 2014 |
| Altrincham VETS4PETS Limited | Handforth | 2013 |
| Altrion Advisory Ltd | London | 2026 |
| Altrion Group UK Ltd | London | 2026 |
| Altrisk Limited | London | 2024 |
| Altrist Limited | London | 2008 |
| Altrium Professional Ltd | Stirling | 2022 |
| Altrius Limited | Atherstone | 2019 |
| Altriva 360 Advisory Limited | Alfreton | 2026 |
| Altrix Consultants Limited | Stroud | 2002 |
| Altrix Ltd | Bishop'S Stortford | 2025 |
| Altro Floors Limited | Letchworth Garden City | 1968 |
| Altro Group Limited | Hertfordshire | 1980 |
| Altro Structural Design Ltd | Cleckheaton | 2021 |
| Altro Whiterock Limited | Letchworth Garden City | 1963 |
| Altronlabs Ltd | London | 2024 |
| Altroy Ltd | Ruislip | 2002 |
| Altru Creations Ltd | London | 2025 |
| Altru FLO Ltd | London | 2024 |
| Altru Limited | Runcorn | 2025 |
| Altrua Limited | Liverpool | 2026 |
| Altrudana Limited | Epsom | 2019 |
| Altruismo Ltd | Felpham, | 2023 |
| Altruist Investments Limited | Whitstable | 2016 |
| Altruistic (Scotland) Limited | Falkirk | 2020 |
| Altruistic Investments Limited | Lydney | 2021 |
| Altruistic Ventures Limited | London | 2020 |
| Altrum UK Limited | Warrington | 2013 |
| Altryte Limited | Maidstone | 2004 |
| Alts Advisers Ltd | Chichester | 2023 |
| Altsun Ltd | Poole | 2025 |
| Alttitude (2005) Limited | Fife | 2005 |
| Altum Aerial Solutions Ltd | Midhurst | 2026 |
| Altum Enterprises Ltd | London | 2016 |
| Altum Finance Limited | London | 2025 |
| Altum Group Limited | London | 2019 |
| Altum Media Ltd | Bovey Tracey | 2021 |
| Altumedia Limited | London | 2024 |
| Altun Bookkeeping Services Limited | London | 2020 |
| Altun Consultancy Ltd | East Boldon | 2021 |
| Altun Law Ltd | Faversham | 2026 |
| Altun Legal Consultancy Ltd | London | 2021 |
| Altun Legal Services Ltd | Faversham | 2025 |
| Altunco Accountancy Limited | London | 2026 |
| Altuntop Catering Ltd | Chatham | 2019 |
| Altura AB Ltd | Preston | 2025 |
| Altura Accounting Ltd | London | 2025 |
| Altura Advisory Limited | Richmond | 2025 |
| Altura Aerial Photography Limited | Bolton | 2014 |
| Altura Capital Advisors Ltd | London | 2026 |
| Altura Consulting Limited | London | 2025 |
| Altura Consulting Services Limited | Harrogate | 2026 |
| Altura Defi Ltd | Liverpool | 2025 |
| Altura Drone Surveys Ltd | Rochester | 2025 |
| Altura Growth Ltd | London | 2026 |
| Altura Industrial Development Limited | Pontypridd | 2015 |
| Altura Renewables and Marine Limited | Immingham | 2021 |
| Altura Safety and Training Limited | Hope Valley | 2014 |
| Altura Security Ltd | London | 2024 |
| Alturas Engineering Ltd | Wallsend | 2025 |
| Alturas Logistics Ltd | Littleborough | 2025 |
| Alture Group Limited | London | 2025 |
| Alturis AI Ltd | Thornbury | 2021 |
| Alturise Ltd | Bristol | 2024 |
| Alturon Limited | Stowmarket | 2025 |
| Alturos Consulting Ltd | Uxbridge | 2025 |
| Alturra Ltd | Sheffield | 2026 |
| Altus 3.2 Limited | Retford | 2026 |
| Altus Access & Rescue Ltd | Plymouth | 2025 |
| Altus Accountancy & Tax Limited | Lewes | 2016 |
| Altus Accountants Limited | Sutton Coldfield | 2020 |
| Altus Advisory Limited | Chippenham | 2016 |
| Altus Business Consulting Limited | Stourbridge | 2005 |
| Altus Capital Ltd | Skipton | 2023 |
| Altus Certification Limited | 20/20 Business Park | 2024 |
| Altus Construction Managment Ltd | Cheadle | 2023 |
| Altus Design Ltd | London | 2022 |
| Altus Engineering Consultants Ltd | Kings Langley | 2025 |
| Altus Enterprises Ltd. | Glasgow | 2012 |
| Altus Health Ltd | Leicester | 2015 |
| Altus Healthcare Limited | Iver | 2017 |
| Altus Imaging Ltd | Tarporley | 2007 |
| Altus Innovations Ltd. | Clydebank | 2003 |
| Altus MEP Ltd | Market Harborough | 2025 |
| Altus Nature Ltd | London | 2026 |
| Altus Performance Ltd | Poole | 2025 |
| Altus Retail Consulting Ltd | Wymondham | 2025 |
| Altus Services Limited | Manchester | 2026 |
| Altusub Ltd | Inverness | 2012 |
| Altuvia Property Consulting Ltd | Oldbury | 2025 |
| Altvelop Ltd | Bromley | 2019 |
| Altvisory Limited | Stanmore | 2021 |
| Altway Energy Solutions Ltd | Liverpool | 2022 |
| Altwise Global Consulting Ltd | London | 2025 |
| Altwood Bailey Accountants Limited | Maidenhead | 2011 |
| Altwood Business & Accountancy Services Limited | Berkshire | 2003 |
| Altwood Energy Advisors Limited | Maidenhead | 2021 |
| Altwood Financial Services Limited | Maidenhead | 2011 |
| Altx Therapeutics Limited | Huntingdon | 2025 |