| Autism Haven CIC | Redruth | 2024 |
| Autism Hertfordshire Limited | Bedford | 2021 |
| Autism Hub Ltd | London | 2025 |
| Autism in Mind Support Ltd | Leigh | 2022 |
| Autism in Racing CIC | London | 2024 |
| Autism Initiatives Northern Ireland | Belfast | 2003 |
| Autism Insight Assessments Ltd | Mildenhall | 2025 |
| Autism Insight Ltd | London | 2025 |
| Autism Ireland Limited | Belfast | 2010 |
| Autism Kids Club Services Ltd | Wellingborough | 2025 |
| Autism Life Centres CIC | Tonypandy | 2015 |
| Autism Milton Keynes Limited | Bedford | 2021 |
| Autism NI (Papa) | Belfast | 2006 |
| Autism North East | Ryton | 2013 |
| Autism Oxford UK Limited | Hollinwodd | 2014 |
| Autism Plus Limited | Doncaster | 1987 |
| Autism Respite and Advocacy Limited | Clacton-On-Sea | 2023 |
| Autism Rocks | London | 2014 |
| Autism Services Group Limited | Adderbury | 2025 |
| Autism Specific Consultancy Services Scotland Ltd | Alford | 2021 |
| Autism Spectrum Connections Cymru | Cardiff | 2013 |
| Autism Supplies and Developments Ltd | Torpoint | 2018 |
| Autism Support & Care Limited | Barnsley | 2007 |
| Autism Sussex Limited | Pembury | 1996 |
| Autism Swindon ABA Ltd | Swindon | 2026 |
| Autism Tascc Services Limited | London | 2003 |
| Autism Together | Wirral | 1991 |
| Autism Treatment Plus Limited | London | 2013 |
| Autism Ulster Limited | Belfast | 2010 |
| Autism Ventures | Bootle | 2010 |
| Autism+Pa Services Ltd | Wrenbury | 2016 |
| Autism-In-Mind Community Interest Company | Sunderland | 2015 |
| Autism.West Midlands | Selly Oak | 1985 |
| Autismadhd Clinic Limited | Poole | 2022 |
| Autismassessmentlondon Ltd | London | 2016 |
| Autistic Foundation | Birmingham | 2017 |
| Autistic Inclusive Meets | Woolwich | 2017 |
| Autistic Society Greater Manchester Area | Manchester | 2001 |
| Autistic Therapist Directory CIC | Selkirk | 2026 |
| Autistically Proud C.I.C. | London | 2022 |
| Auto Diviso Limited | Birmingham | 2019 |
| Auto-Sengineering Ltd | Ilford | 2014 |
| Auto-Servicos Ltd | Street | 2020 |
| Autocare PVT Ltd | Basildon | 2014 |
| Autograph Dental Limited | Eastbourne | 2022 |
| Autoimmune Clinic London Ltd | Bristol | 2018 |
| Autoimmune Nutrition Clinic Ltd | Harrogate | 2019 |
| Autoimmune Rescue CIC | Mildenhall | 2025 |
| Autolycus Biomedical Consulting (ABC) Ltd | South Croydon | 2019 |
| Autonomie Ltd | Belfast | 2023 |
| Autonomy AID Care Ltd | Manchester | 2026 |
| Autonomy Care Limited | Melksham | 2008 |
| Autonomy for ALL Limited | London | 2012 |
| Autonomy Health Ltd | Mitcham | 2019 |
| Autonomy Healthcare Limited | Derby | 2011 |
| Autonomy Innovations Limited | Derby | 2026 |
| Autonomy Life Ltd | Melksham | 2000 |
| Autonomy Medical Services Limited | Hainault | 2013 |
| Autonomy Motor Sports Club Limited | Leeds | 2009 |
| Autonomy Plus Limited | Melksham | 2017 |
| Autonomy Securities Limited | Derby | 2011 |
| Autopsy Cover Limited | Leeds | 2019 |
| Autopsy Services Ltd | Malvern | 2026 |
| Autumn Apples Limited | Forfar | 2023 |
| Autumn Blossoms Ltd | Barnoldswick | 2017 |
| Autumn Breeze Healthcare Ltd | Walsall | 2025 |
| Autumn Care Group Ltd | Faversham | 2026 |
| Autumn Care Homes Ltd | Witham | 2013 |
| Autumn Cottage Childcare Limited | Hook | 2022 |
| Autumn Days Care Limited | North Harrow | 2006 |
| Autumn House Care Limited | Barnet | 2010 |
| Autumn Leaves Psychotherapy Ltd | Tadworth | 2023 |
| Autumn Lodge Hove Limited | Hove | 2018 |
| Autumn Residential Care Limited | Derby | 2025 |
| Autumn Spa Skin & Beauty Clinic Limited | West Bromwich | 2010 |
| Autumn Years Care Group Limited | Thame | 2017 |
| Autumn Years CIC | Bristol | 2026 |
| Autumn Years Community Care Limited | Bristol | 2023 |
| Autumn Years Friends Ltd | Bristol | 2024 |
| Autumna Limited | Tunbridge Wells | 2017 |
| Autumngreen Ltd | Louth | 2026 |
| Autus Cumbria Limited | Barrow-In-Furness | 2014 |
| Auxeum UK Ltd | Birmingham | 2026 |
| Auxicare Limited | Dagenham | 2024 |
| Auxilio Care Limited | Birmingham | 2015 |
| Auxilio Holdings Limited | Birmingham | 2013 |
| Auxilio Housing Limited | Birmingham | 2015 |
| Auxilium Angels Ltd | Cambridge | 2025 |
| Auxilium Care and Support Ltd | Cambridge | 2024 |
| Auxilium Care Limited | London | 2024 |
| Auxilium Health Solutions Ltd | Exeter | 2014 |
| Auxilium Healthcare Ltd | Wolverhampton | 2022 |
| Auxilium Manus Care Ltd | St. Helens | 2024 |
| Auxin Healthcare Limited | Spalding | 2023 |
| Auzoni Limited | Leicester | 2023 |
| AV Angels Limited | Coventry | 2025 |
| AV Care Services Limited | Leeds | 2013 |
| AV Dance Magic Ltd | Taunton | 2019 |
| AV Dental Limited | York | 2025 |
| AV Dermatology Limited | London | 2025 |