| ALL Seasons Underwriting Agencies Limited | London | 1996 |
| ALL Shore Holdings Limited | Wolverhampton | 2023 |
| ALL Silva Ltd | Lydney | 2024 |
| ALL SIX Chester Limited | London | 2025 |
| ALL SIX Liverpool Limited | London | 2023 |
| ALL SIX Manchester Limited | London | 2026 |
| ALL SIX York Limited | London | 2023 |
| ALL Sorted Financial Planning Limited | Southport | 2016 |
| ALL Sorted Mortgages Limited | Southport | 2023 |
| ALL Sport Insurance Services Limited | Torquay | 2015 |
| ALL Sport Ireland Limited | Torquay | 2023 |
| ALL Square Finance Limited | Skipton | 2012 |
| ALL Star Funding Solutions Limited | Bedford | 2017 |
| ALL Stars Finance Limited | Loughton | 2021 |
| ALL Stars UK Debtco Limited | Slough | 2024 |
| ALL Steels Trading Holdings Limited | Thirsk | 2017 |
| ALL Successful Group Ltd | Gravesend | 2025 |
| ALL TEL Communications Limited | Wotton Under Edge | 2012 |
| ALL That I AM UN Limited | Yarm | 2014 |
| ALL Things Considered Services Ltd | London | 2023 |
| ALL Things Financial Limited | | 2004 |
| ALL Things Nice Group Ltd | Grays | 2023 |
| ALL Things Wealth Ltd | Ely | 2020 |
| ALL Together Holdings Limited | London | 2023 |
| ALL Traffic Holdings Ltd | Willenhall | 2023 |
| ALL Weather Strategy Ltd | London | 2020 |
| ALL Weathers Lottery CIC | Telford | 2021 |
| ALL Work and Social Holdco Limited | Manchester | 2020 |
| ALL Works Services Limited | Worthing | 2025 |
| ALL YOU Need Mortgages Limited | Southend-On-Sea | 2016 |
| ALL Zone Ventures Limited | London | 2019 |
| All-In-One-Financial@Your-Solutions Ltd | London | 2022 |
| All-Pak Engineering Holdings Limited | Stamford | 2019 |
| ALL2PLAY4 Holdings Limited | Bournemouth | 2025 |
| ALL4HOLDINGS Limited | Burnley | 2017 |
| Alla HQ Ltd | London | 2026 |
| Allaboutfinance Limited | London | 2008 |
| Allaboutgroup Holdings Ltd | Poole | 2016 |
| Allada Development Corporation Ltd | Cardiff | 2025 |
| Allam Capital Limited | London | 2021 |
| Allan and Sons Holdings Ltd | Finchley | 2025 |
| Allan Capital Ltd | Glasgow | 2023 |
| Allan Corfield Group Limited | Dunfermline | 2024 |
| Allan Family Limited | Sutton | 2025 |
| Allan G Stewart Mortgages Ltd | By Lochgilphead | 2024 |
| Allan Group Holdings Ltd | Glasgow | 2023 |
| Allan Investment Management Limited | Northampton | 2005 |
| Allan Investment Strategies Ltd | Altrincham | 2025 |
| Allan Liddle (Holding) Limited | Gateshead | 2014 |
| Allan Marlow Mortgages Limited | Northamptonshire | 2006 |
| Allan Packer Capital Limited | Fareham | 2016 |
| Allan Sichel Limited | Tiverton | 1951 |
| Allandale Investment Group Ltd | Accrington | 2026 |
| Allanfauld (Holdings) Limited | Glasgow | 1991 |
| Allanite Capital (UK) Limited | Greenford | 2021 |
| Allans IP Limited | Armagh | 2026 |
| Allans PMI Limited | New Milton | 2002 |
| Allarburn Group Limited | Elgin | 2017 |
| Allarburn Holdings Limited | Elgin | 1959 |
| Allard Investments Limited | Bristol | 2026 |
| Allard Wealth Ltd | London | 2020 |
| Allaro Holdings Limited | Faversham | 2013 |
| Allars Holdings Limited | Kingston Upon Thames | 2025 |
| Allasa Limited | London | 2023 |
| Allavent Limited | London | 2016 |
| Allawah Ltd | London | 2007 |
| Allbart Group Limited | Sheerness | 2017 |
| Allberry Holdings Limited | Hornchurch | 2025 |
| Allbon Holdings Ltd | Ipswich | 2025 |
| Allbright Bishop Rowley Limited | Leicester | 2000 |
| Allbright Holdings Limited | Bognor Regis | 2025 |
| Allbright Law Offices (London) Limited | London | 2017 |
| Allbritain Holdings Limited | Worcester | 2022 |
| Allbro Enclosures Ltd | Sunderland | 2021 |
| Allbrook Group Limited | Southampton | 2016 |
| Allcare Community Support Holdings Limited | Salhouse | 2025 |
| Allchin Holdings Limited | London | 2021 |
| Allcity Finance Ltd. | London | 2014 |
| Allclaims Consultancy Limited | Southend-On-Sea | 2021 |
| Allclout UK Ltd | Ashford | 2020 |
| Allcontrast Holdings Limited | Brierley Hill | 2025 |
| Allcover Financial Services Ltd | Chesham | 2021 |
| Allcover Insurance Brokers Ltd | London | 2004 |
| Alldacc Group Ltd | Reading | 2024 |
| Allday Time Systems (Holdings) Limited | Farnborough | 2025 |
| Alldec Holdings Limited | Sunderland | 2023 |
| Allder Group Limited | Reading | 2018 |
| Allderidge Properties Limited | Hull | 2008 |
| Alldirectioncapital Ltd | London | 2025 |
| Alldoctors Holdings Ltd | Milton Keynes | 2022 |
| Alldubee Ltd | Leeds | 2019 |
| Alleans Capital International Limited | London | 2019 |
| Alleans Renewables Capital Limited | London | 2019 |
| Allect Holdings Limited | Warwickshire | 2017 |
| Allect Investments Limited | Stratford-Upon-Avon | 2024 |
| Allectus Quantum Holdings Ltd | Epsom | 2021 |
| Allectus Quantum Ltd | Epsom | 2021 |
| Allegiant Holdings Ltd | London | 2023 |
| Allegis Services Holdings Limited | Bracknell | 2019 |
| Allegn Limited | London | 2021 |