| Apsl Investments Limited | Peterborough | 2021 |
| Apsley Accounts Ltd | Apsley | 2024 |
| Apsley Analytics Limited | Salisbury | 2013 |
| Apsley Consultancy Ltd | Brighton | 2022 |
| Apsley Consulting Limited | Bristol | 2017 |
| Apsley Engineering Ltd | Ticehurst | 2006 |
| Apsley Estates Limited | Colchester | 2000 |
| Apsley Group International Ltd | Weybridge | 2013 |
| Apsley House Consulting Ltd | Oxford | 2025 |
| Apsley Logistics Limited | London | 2020 |
| Apsley Management Limited | London | 1989 |
| Apsley Tailors Limited | London | 2003 |
| Apsley Trustees Limited | Oxford | 2024 |
| Apsr Limited | London | 2016 |
| Apstaf Limited | Liverpool | 2020 |
| Apstead Ltd | Birmingham | 2022 |
| Apstech Advisors Limited | Amersham | 2021 |
| Apstechs Infra Ltd | Colchester | 2022 |
| Apstruct Limited | London | 2026 |
| APT Accounting Ltd | London | 2023 |
| APT Action on Poverty | Bristol | 1984 |
| APT Advisory Limited | Newtownards | 2021 |
| APT Architects + Designers Ltd | London | 2017 |
| APT Architectural Services Ltd | Stoke-On-Trent | 2019 |
| APT Auditors Ltd | London | 2023 |
| APT Building Compliance Ltd | Stockport | 2025 |
| APT Business Accountancy Ltd | Shoreham-By-Sea | 2021 |
| APT Consulting (UK) Limited | Uttoxeter | 2011 |
| APT Consulting Project Management Limited | London | 2014 |
| APT Contracting Limited | Dunstable | 2024 |
| APT Design Limited | Wigston | 2001 |
| APT Design Services Limited | Southam | 2017 |
| APT Digital Services Ltd | Trafford Park | 2023 |
| APT Ingredients Ltd | Kidderminster | 2025 |
| APT Legal Limited | Nottingham | 2016 |
| APT Locum Ltd | London | 2020 |
| APT Payroll Services Ltd | Shepton Mallet | 2025 |
| APT Performance Media Ltd | London | 2013 |
| APT Photography Ltd | Shrewsbury | 2013 |
| APT Planning & Development Limited | Whitekirk | 2012 |
| APT Process Solutions Ltd | Glasgow | 2026 |
| APT Projects Limited | Birmingham | 2023 |
| APT Rigging Ltd | Middlesbrough | 2025 |
| APT Secondaries Transaction Solutions Limited | London | 2026 |
| APT Services Limited | West Midlands | 1991 |
| APT Smith-Thomas Ltd | Berwick Upon Tweed | 2017 |
| APT Squirrel Designs Ltd | Warrington | 2024 |
| APT Strategic Consulting Limited | Uttoxeter | 2023 |
| APT Subsea Services Ltd | St Ives | 2017 |
| APT Support Ltd. | Bicester | 2014 |
| APT Support Services Ltd | Manchester | 2021 |
| APT Tax Accountants Ltd | London | 2025 |
| APT Technical Design Ltd | Tonbridge | 2009 |
| APT the Agency Ltd | London | 2024 |
| APT Trading (UK) Ltd | London | 2024 |
| APT Translations Ltd | Dorchester | 2007 |
| APT Transtelex Ltd | Dorchester | 1974 |
| APT Works Limited | London | 2009 |
| Apt-Itude Ltd | Northampton | 2009 |
| APT21 Fire Safety Ltd | Dunmow | 2025 |
| Aptagenix Oncology Ltd | Birmingham | 2026 |
| Aptalk Ltd | Lytham St.Annes | 2013 |
| Aptamer Diagnostics Limited | York | 2008 |
| Aptamer Group PLC | York | 2014 |
| Aptamer Solutions Limited | York | 2012 |
| Aptamer Therapeutics Limited | York | 2014 |
| Aptamu Limited | London | 2021 |
| Aptare Advisory Ltd | Glasgow | 2025 |
| Aptargroup UK Holdings Limited | Leeds | 2002 |
| Aptc Ltd | Lancaster | 2025 |
| Aptec Consultancy Ltd | London | 2017 |
| Aptec Industries Limited | Huddersfield | 2009 |
| Aptec Renewables Limited | Huddersfield | 2010 |
| Aptech (Powder Systems) Limited | Market Harborough | 1994 |
| Apteligen Limited | Watford | 2010 |
| Aptelligent Consultancy Limited | London | 2010 |
| Apteno Consulting Ltd | Bicester | 2017 |
| Aptenor Limited | Alresford | 2026 |
| Apter Consulting Ltd | Newport | 2021 |
| Apterna Limited | London | 2011 |
| Apteryx Limited | Taunton | 2021 |
| Apteum Limited | Bilston | 2022 |
| Apthorp Asbestos Management Ltd | Camberley | 2024 |
| Aptide Limited | Stoke-On-Trent | 2008 |
| Aptiflow Limited | Poole | 1998 |
| Aptiia Ltd | Longfield | 2023 |
| Aptilium Ltd | Billingshurst | 2019 |
| Aptim-Solutions Limited | London | 2019 |
| Aptimarketing Ltd | Stockport | 2025 |
| Aptis Consulting Limited | Waterlooville | 2019 |
| Aptis PAY Ltd | London | 2026 |
| Aptitude Accounting Limited | London | 2016 |
| Aptitude Agency Ltd. | Cambridge | 2009 |
| Aptitude Business Consulting Limited | Aberdeen | 2015 |
| Aptitude Consultancy Ltd | Kenley | 2022 |
| Aptitude Financial Solutions Limited | Aberdeen | 2025 |
| Aptitude Health UK Limited | London | 2023 |
| Aptitude Investments Limited | Ormskirk | 2024 |
| Aptitude Software Group PLC | London | 1981 |
| Aptitude Support Ltd | Belfast | 2025 |