| App Assure Ltd | Westmeston | 2024 |
| App Audits Limited | Bridlington | 2024 |
| App Boss Ltd | Barry | 2024 |
| App Consultancy Limited | Stroud | 2014 |
| App Consultants Ltd | London | 2023 |
| App Consulting Ltd | Birmingham | 2024 |
| App Dalmeny (Consulting) Ltd | South Queensferry | 2018 |
| App Dalmeny Ltd | South Queensferry | 2011 |
| App Holdco Limited | Eynsham | 2013 |
| App Holdings Limited | Cambridge | 2007 |
| App Insight Ltd | London | 2021 |
| App Management Cardiff Ltd | Cardiff | 2025 |
| App MTD Ltd | High Wycombe | 2022 |
| App Survey Solutions Ltd | Aberdeen | 2023 |
| App With Web Limited | London | 2013 |
| App-Econ Ltd | Sidcup | 2019 |
| Appa IT Solutions Limited | Melton Constable | 2013 |
| Appa Mount Pleasant Limited | Oxford | 2003 |
| Appaloosa Geoconsultants Limited | Edinburgh | 1999 |
| Appara Ltd | Ashton-Under-Lyne | 2020 |
| Apparatus Holdings Limited | Chatham | 2023 |
| Apparatus Limited | Carnforth | 2008 |
| Apparatus Software Limited | Chatham | 2019 |
| Apparel Concepts Ltd | Preston | 2023 |
| Apparel Group Limited | Burton On Trent | 2021 |
| Apparel Inspired Ltd | Harrogate | 2023 |
| Apparel Matters Limited | Manchester | 2003 |
| Apparent Marketing Limited | Loughborough | 2026 |
| Apparent Space Limited | London | 2024 |
| Apparent Wind Ltd | Colchester | 2018 |
| Apparition Content Ltd | Droitwich | 2025 |
| Apparition Marketing and Design Limited | Beccles | 2009 |
| Apparition Studio Ltd | London | 2026 |
| Appassionata Giacomo Leopardi Limited | Cossington | 2009 |
| Appassionata Ltd | Cossington | 2005 |
| Appaware Ltd | Redmile | 2019 |
| Appchemy Limited | Leeds | 2016 |
| Appco Group Energy Ltd | London | 2000 |
| Appco Group Financial Services Ltd | London | 2001 |
| Appco Group Telecommunications Ltd | London | 1996 |
| Appdraft Limited | London | 2018 |
| Appe Pharma Consulting Limited | Bishop'S Stortford | 2012 |
| Appeal Consulting Limited | Bury | 2007 |
| Appeal to Heaven Limited | London | 2019 |
| Appealing HR Ltd | Waterlooville | 2010 |
| Appealing Solutions Limited | Worthing | 2023 |
| Appear Online Limited | Swansea | 2023 |
| Appeel Geoscience Ltd | Saxmundham | 2015 |
| Appelboam Ltd | Waterlooville | 2024 |
| Appella Consulting Limited | Gerrards Cross | 2012 |
| Appella Limited | Chichester | 2004 |
| Appello Holdings Limited | New Milton | 2019 |
| Appello Limited | New Milton | 2007 |
| Appendix B Limited | Old Coulsdon | 2012 |
| Appendix Productions Limited | Sudbury | 2001 |
| Appends Consulting Ltd | Stockport | 2015 |
| Appening Events Limited | London | 2019 |
| Apperley Holdings Ltd | Stroud | 2024 |
| Apperley Honing Machines Limited | Evesham | 2006 |
| Apperley Wealth Management Limited | Henley-On-Thames | 2023 |
| Appersett Limited | West Yorkshire | 2005 |
| Apperture Ltd | London | 2020 |
| Appetite 4 Data Ltd | Norwich | 2026 |
| Appetite Consultants Limited | Henham | 2017 |
| Appetite Online Ltd | Leeds | 2022 |
| Appetite Project Management Ltd | Clitheroe | 2008 |
| Appetite Publicity Ltd | Brighton | 2021 |
| Appex Technicians Ltd | Purley | 2022 |
| Appexreputebpo Ltd | Bradford | 2025 |
| Appfluent Accounting Ltd | Liverpool | 2020 |
| Appford Services Limited | London | 2019 |
| Appg NI Economy Ltd | Bangor | 2022 |
| Appgrad Limited | London | 2012 |
| Apphia Consulting Limited | Wisbech | 2018 |
| Apphia Holdings Ltd | Wisbech | 2022 |
| Appia Infrastructure Solutions Limited | Wokingham | 2008 |
| Appiah & Associates Limited | Stockport | 2007 |
| Appiah Analytics LLC Ltd | London | 2025 |
| Appian Advisory Limited | Rickmansworth | 2026 |
| Appian Capital U.K. Limited | London | 2025 |
| Appian Energy Consulting Ltd | Bishops Stortford | 2023 |
| Appian Trading Limited | London | 2003 |
| Appier UK Co., Ltd. | Barnet | 2019 |
| Appietite Limited | Coventry | 2019 |
| Appila Limited | Gerrards Cross | 2004 |
| Appin Consultancy Services Limited | York | 2025 |
| Appin Data Services Limited | Glasgow | 2022 |
| Appin House Consulting Ltd | York | 2018 |
| Appinio Limited | London | 2021 |
| Appkraft Limited | Lancaster | 2014 |
| Appla Inc Limited | London | 2024 |
| Applaud Media Limited | Peterborough | 2015 |
| Applause Accountancy Services Limited | Houghton Le Spring | 2009 |
| Applause App Quality UK Ltd | London | 2015 |
| Applause Konsult Ltd | London | 2013 |
| Apple & BEE Limited | Rotherham | 2016 |
| Apple 2 Asparagus Limited | Westbury-On-Trym | 2005 |
| Apple Accountancy Ltd | Newport | 2018 |
| Apple Accountancy Services Limited | Borehamwood | 2008 |
| Apple Advisory Group Ltd | Waltham Abbey | 2007 |