| Alliance Finance Consultancy Ltd | London | 2021 |
| Alliance Financial Services (UK) Limited | London | 2018 |
| Alliance Flood Solutions Ltd | Kirkby In Ashfield | 2013 |
| Alliance Fluid Handling Limited | Doncaster | 2008 |
| Alliance for African Minds Ltd | Watford | 2024 |
| Alliance for Change Limited | Stretford, Manchester | 2025 |
| Alliance for Climate Solutions GB C.I.C. | Gainsborough | 2024 |
| Alliance for Inclusion Ltd | Horsham | 2024 |
| Alliance for Natural Health International | Ravenshead | 2002 |
| Alliance for Rabies Control | Glasgow | 2005 |
| Alliance for Reducing Antimicrobial Resistance | London | 2025 |
| Alliance GAS & Recertification Ltd | Birmingham | 2021 |
| Alliance Gestion Ltd | London | 2026 |
| Alliance Global (UK) Limited | Feltham | 2010 |
| Alliance Global Partners Ltd | London | 2026 |
| Alliance Group Solutions Ltd | Kirkby In Ashfield | 2013 |
| Alliance Healthcare Initiatives Limited | Swindon | 2022 |
| Alliance Infinite Ltd | London | 2024 |
| Alliance Innovation Ltd | Sutton Coldfield | 2023 |
| Alliance Insolvency Partners Limited | Sawbridgeworth | 2020 |
| Alliance Inventories Limited | Bury St Edmunds | 2019 |
| Alliance Investment Management Ltd | London | 2025 |
| Alliance Kapital Ltd | Barnet | 2021 |
| Alliance Law Solicitors Limited | Leeds | 2010 |
| Alliance Legal Group Ltd | Manchester | 2022 |
| Alliance Legal Limited | Plymouth | 2019 |
| Alliance Legal Solutions Ltd | London | 2016 |
| Alliance Linguistics Limited | London | 2016 |
| Alliance London Ltd | Sevenoaks | 2019 |
| Alliance Long Acre Limited | | 1940 |
| Alliance Management & Consultancy Ltd | Banbury | 2020 |
| Alliance Management Services Ltd. | Hook | 1988 |
| Alliance Management Solutions Limited | London | 2020 |
| Alliance Manufacturing and Trading Company Limited | London | 2009 |
| Alliance Marine Limited | London | 2008 |
| Alliance Marketing Agency Limited | Torfaen | 2017 |
| Alliance Media Partners North Limited | Glasgow | 2018 |
| Alliance Medical Group Limited | Warwick | 2007 |
| Alliance Medical Holdings Limited | Warwick | 2000 |
| Alliance NDT Ltd | Washington | 2019 |
| Alliance Nexus Consulting Limited | Glossop | 2024 |
| Alliance of Construction Networks Limited | Farnham | 2012 |
| Alliance of Ngos and Csos for South-South Cooperation Limited | London | 2019 |
| Alliance OIL Company Limited | Norwich | 2016 |
| Alliance Online Limited | London, | 2011 |
| Alliance Pack Limited | Aylesford | 2014 |
| Alliance Partnership Solutions Ltd | London | 2024 |
| Alliance Payroll Services Limited | Droitwich | 2005 |
| Alliance Petroleum 1 Ltd | Shetland | 2025 |
| Alliance Photography Studios Ltd | Southampton | 2021 |
| Alliance Powered Solutions Ltd | Eastbourne | 2020 |
| Alliance Procurement Solutions Limited | Park Row | 2016 |
| Alliance Productions Limited | London, | 2015 |
| Alliance Project Controls Limited | Glasgow | 2008 |
| Alliance QA Services Limited | Chepstow | 2000 |
| Alliance Recruitment Consultants Ltd | London | 2023 |
| Alliance Sales Support Services Limited | Norwich | 2013 |
| Alliance Services Ltd | Watford | 2008 |
| Alliance Site Engineers & Surveyors Ltd | Kilmarnock | 2014 |
| Alliance Solicitors Ltd | Slough | 2018 |
| Alliance Strategy Consulting Ltd | London | 2022 |
| Alliance Street Accountancy Ltd | Basildon | 2024 |
| Alliance Support Solutions CIC | Cheltenham | 2025 |
| Alliance Surgical PLC | Birmingham | 2004 |
| Alliance Wharfies Ltd | London | 2021 |
| ALLIANCE24 Consulting Limited | London | 2020 |
| Alliancehr Limited | Camberley | 2005 |
| Alliances-Global Solutions Limited | London | 2016 |
| Alliancevisas Limited | Harrow | 2012 |
| Alliancexp Limited | Tavistock | 2025 |
| Alliander Limited | Cheltenham | 2019 |
| Alliants Limited | Southampton | 2009 |
| Allianz Engineering Inspection Services Limited | Surrey | 2005 |
| Allianz Secure Ltd | Barking | 2022 |
| Allicom Global Ltd | Sherborne | 2014 |
| Allie Engineering Limited | Warrington | 2017 |
| Allie INT Ltd | Enfield | 2022 |
| Allie Wnuk Consulting Limited | Staines-Upon-Thames | 2023 |
| Allied & Co Limited | London | 2013 |
| Allied (a) Consultancy Limited | Southend-On-Sea | 2013 |
| Allied Accountancy Limited | Royston | 2017 |
| Allied Accountants & Tax Consultants Ltd | Birmingham | 2022 |
| Allied Accountants Ltd | Salford, Manchester | 2021 |
| Allied Accounting Services Limited | London | 2005 |
| Allied Advantage Limited | London | 2018 |
| Allied Affinity Limited | Epsom | 1980 |
| Allied Africa Group Ltd | Harrow | 2025 |
| Allied Air Limited | Smethwick | 2003 |
| Allied Approvals Ltd | Stoke-On-Trent | 2008 |
| Allied Assessment Holdings Limited | Shefford | 2022 |
| Allied Associates (Geophysical) Limited | Dunstable | 1988 |
| Allied Associates Ltd | Leamington Spa | 2024 |
| Allied Axiom Ltd | Carnforth | 2016 |
| Allied Bakeries Limited | London | 1926 |
| Allied Beau Consultancy Limited | Stockport | 2024 |
| Allied Business Consult Ltd | Glasgow | 2009 |
| Allied Business Management Consulting Limited | London | 2014 |
| Allied Capital Financials Limited | Manchester | 2017 |
| Allied Cbam Limited | Armagh | 2025 |
| Allied Certification Services Limited | Stanford-Le-Hope | 2014 |