| Addaura Limited | Sittingbourne | 2003 |
| Addax Film Productions Limited | Brighton | 1980 |
| Addax Petroleum Development Limited | London | 2001 |
| Addax Petroleum UK Limited | London | 2012 |
| Addback Limited | Lancashire | 2003 |
| Addboost Ltd | Doncaster | 2024 |
| Addclad Limited | Derbyshire | 2000 |
| Addconvert Ltd | Dunfermline | 2026 |
| Addcountax Ltd | London | 2014 |
| Adddg Ltd | Darlington | 2023 |
| Adddzero Limited | Sleaford | 2023 |
| Adde & Co Limited | Nr Hungerford | 2008 |
| Adde (Redditch) Holdings Limited | Hayle | 2010 |
| Addecet Ltd | London | 2022 |
| Addeco Group Solutions Limited | London | 2025 |
| Added Accounting Limited | Gorebridge | 2012 |
| Added Extra Limited | Cheadle | 2015 |
| Added Genius Limited | Cranleigh | 2024 |
| Added Lightness Limited | Warrington | 2017 |
| Added Plus Ltd | New Milton | 2013 |
| Added Scientific Limited | Nottingham | 2014 |
| Added Value Accountancy Ltd | London | 2018 |
| Added Value Architecture Limited | Congleton | 2017 |
| Added Value Consultants Limited | Stourbridge | 2013 |
| Added Value Financial Consulting Services Limited | Maidenhead | 2008 |
| Added Value Portal Limited | Hull | 2019 |
| Added Value Ventures Limited | Watford | 2021 |
| Addedmile Ltd | Beckenham | 2024 |
| Addee Business & Finance Analytics Limited | London | 2025 |
| Addeelia Consultancy Limited | Belfast | 2017 |
| Addelam Services Limited | Harpenden | 2020 |
| Addelo Trading Ltd | South Croydon | 2023 |
| Addelsee - Smith Limited | Sleaford | 2002 |
| Addend Ltd | London | 2022 |
| Adder Bookkeeping Ltd | London | 2017 |
| Adder-Vax Limited | Manchester | 2025 |
| Adderbury Carpet Company Limited | Nr Banbury | 2005 |
| Adderbury QS Services Limited | Leamington Spa | 2016 |
| Addere Capital Ltd | London | 2020 |
| Addere Valorem Ltd | Newcastle Upon Tyne | 2012 |
| Adderha Ltd | Rotherham | 2013 |
| Adderley Associates Ltd | North Shields | 2022 |
| Adderley Creative Ltd | Dalkeith | 2025 |
| Adderley House Ltd | Bideford | 2025 |
| Adderley Ltd | Edinburgh | 2018 |
| Adderley Recruitment Group Limited | London | 2019 |
| Adders Accountants Limited | Northampton | 2011 |
| Adderson Consultancy Limited | Alton | 1996 |
| Adderstone Consulting Ltd. | Newcastle Upon Tyne | 2000 |
| Addes Advisory Limited | Stratford Upon Avon | 2024 |
| Addev Materials UK Limited | Poole | 1996 |
| Addeyannie Limited | Birmingham | 2015 |
| Addfin Consult Limited | London | 2025 |
| Addfluence Ltd | Potters Bar | 2025 |
| Addguru Limited | London | 2007 |
| Addi London Ltd | London | 2023 |
| Addible Ltd | Stockton-On-Tees | 2020 |
| Addicted 2 PPC Limited | Burgess Hill | 2021 |
| Addicted Content Limited | Norwich | 2013 |
| Addicted Marketing Ltd | Wrexham | 2022 |
| Addiction Advocates Ltd | Wallasey | 2026 |
| Addictive Creations Ltd | Newport Pagnell | 2022 |
| Addictive Digital Ltd | Sale | 2024 |
| Addictive Pixel Limited | Etchingham | 2009 |
| Addicus Plus Limited | Poole | 2004 |
| Addidat Ltd | Magdalen Laver | 2022 |
| Addie B Consulting Ltd | London | 2026 |
| Addies Limited | Fleetwood | 2013 |
| Addin Limited | Sheffield | 2008 |
| Adding IT UP Ltd | Brighton | 2023 |
| Adding Limited | London | 2010 |
| Adding Value Consultancy Ltd | Liverpool | 2014 |
| Addington Construction Consultants Limited | West Malling | 2025 |
| Addington Consultancy Limited | London | 2025 |
| Addington Court Property Limited | Camberley | 2017 |
| Addington Development Tree Limited | Plaxtol | 2025 |
| Addington Green Management Limited | West Malling | 2014 |
| Addingyou Limited | Northampton | 2024 |
| ADDINSERVICES18 Limited | Cardiff | 2018 |
| Addionics Limited | London | 2017 |
| Addis & Yassir Ltd | St Mary Hill | 2021 |
| Addis Consult Ltd | London | 2025 |
| Addis Consulting Limited | St. Albans | 2010 |
| Addis Town Planning Ltd | Penrith | 2018 |
| Addiscombe Environmental Consultants Limited | Oxted | 2004 |
| Addison & Co (Teesdale) Limited | Co.Durham | 2002 |
| Addison & Co Trustees Limited | Barnard Castle | 2026 |
| Addison Aaron (Birmingham) Limited | Birmingham | 2009 |
| Addison ABC Limited | Hounslow | 2024 |
| Addison Accounting Limited | Woodhouse | 2008 |
| Addison Accounts & Training Ltd | Bedford | 2015 |
| Addison Accounts and Business Consultants Limited | London | 2023 |
| Addison Alliance Limited | London | 2005 |
| Addison and Holland Park Veterinary Clinic Limited | Rye | 2010 |
| Addison and Khan Solicitors London Limited | Essex | 2014 |
| Addison Associates Limited | Redhill | 2026 |
| Addison Atlas Ltd | London | 2024 |
| Addison Bradley Consulting Ltd | Hampton | 2026 |
| Addison Clark Ltd | Newbury | 2017 |
| Addison Clark Search Limited | Haywards Heath | 2022 |