| Citadel Ministries | Horsham | 1990 |
| Citadel of Grace Ltd | Colchester | 2025 |
| Citadel Parking Limited | Dawlish | 2006 |
| Citadel Support Services Ltd | London | 2025 |
| Citadel Temple Investment Ltd | Edinburgh | 2022 |
| Citaldel Limited | London | 2020 |
| Citi Education Ltd | London | 2019 |
| Citi Electrics Ltd | Uxbridge | 2003 |
| Citi Group Development Ltd | London | 2011 |
| Citi Healthcare Plan Trust Limited | London | 2024 |
| Citi Living Investments Ltd | Manchester | 2025 |
| Citic Construction (UK) Limited | London | 2015 |
| Citidogs Ltd | Melrose | 2010 |
| Cities & Collaboration Ltd | London | 2015 |
| Citifaith Church | Swindon | 2004 |
| Citikane Investments Limited | Waltham Cross | 2014 |
| Citiline Consultants Ltd | Luton | 2017 |
| Citiline Properties Ltd | Luton | 2018 |
| Citipharm Ltd | Aldershot | 2019 |
| Citiplay Limited | Leeds | 2003 |
| Citipost Limited | Erith | 1997 |
| Citisense Ltd | London | 2019 |
| Citizen Canine Limited | Guildford | 2023 |
| Citizen DRY Cleaners London Ltd | Barnet, | 2021 |
| Citizen DRY Cleaners Ltd | Luton | 2017 |
| Citizen Entertainment Ltd | London | 2012 |
| Citizen Focused Research and Development Ltd | West Bromwich | 2024 |
| Citizen Hub South West London CIC | London | 2025 |
| Citizen Hub ST Neots CIC | St Neots | 2024 |
| Citizen Seven Ltd | Weybridge | 2020 |
| Citizen Shareholders International Ltd | Cardiff | 2019 |
| Citizen Window Cleaning Ltd | Larbert | 2020 |
| Citizencard Limited | London | 1998 |
| Citizens Advice - Hart District Limited | Fleet | 2006 |
| Citizens Advice and Rights Fife Limited | Glenrothes | 1997 |
| Citizens Advice Bradford & Airedale and Bradford Law Centre Ltd | Bradford | 2002 |
| Citizens Advice County Durham | Spennymoor | 2013 |
| Citizens Advice Darlington, Redcar and Cleveland | Darlington | 2005 |
| Citizens Advice East Suffolk Ltd | Lowestoft | 2006 |
| Citizens Advice East Sussex | St Leonards On Sea | 2005 |
| Citizens Advice Edinburgh Limited | | 2007 |
| Citizens Advice Gateshead | Gateshead | 1991 |
| Citizens Advice Gosport | Gosport | 2006 |
| Citizens Advice Greater Manchester Limited | Salford | 2017 |
| Citizens Advice Hampshire | Portsmouth | 2007 |
| Citizens Advice Hillingdon Ltd | Stanmore | 1995 |
| Citizens Advice in East Dorset and Purbeck Ltd. | Dorset | 1998 |
| Citizens Advice Lancashire West | Lancashire | 1999 |
| Citizens Advice Limited | London | 1982 |
| Citizens Advice Manchester | Manchester | 1992 |
| Citizens Advice Merton and Lambeth Limited | Surrey | 1994 |
| Citizens Advice MID Lincolnshire | Boston | 2005 |
| Citizens Advice Service in the Borough of Wigan | Leigh | 1989 |
| Citizens Advice Services Corby & Kettering | Corby | 2007 |
| Citizens Advice Shropshire | Shrewsbury | 2000 |
| Citizens Advice Solihull Borough | Birmingham | 2011 |
| Citizens Advice Sort Group Ltd | Manchester | 2012 |
| Citizens Advice South Warwickshire | Warwickshire | 2004 |
| Citizens Advice South West Surrey | Godalming | 1996 |
| Citizens Advice Stroud & Cotswold Districts Limited | Stroud | 2002 |
| Citizens Advice Sunderland | Sunderland | 2007 |
| Citizens Advice Swansea Neath Port Talbot Limited | Swansea | 1983 |
| Citizens Advice Tandridge District | Caterham | 2011 |
| Citizens Advice Thanet | Margate | 2001 |
| Citizens Advice Woking | Woking | 1991 |
| Citizens for Change | London | 2009 |
| Citizens in Power | Totnes | 2022 |
| Citizens of Light Church Ltd | Leeds | 2024 |
| Citizens UK Charity | London | 2004 |
| Citizens' Card Alliance Limited | Cambridge | 2004 |
| Citizenship in Christ Fellowship | London | 2000 |
| Citn United Kingdom (UK) District Society | London | 2023 |
| Cito Facilities Ltd | Carlisle | 2019 |
| Citrin Holdings Ltd | Nottingham | 2025 |
| Citrina Foundation UK Limited | London | 1997 |
| Citrine Beauty & Aesthetics Ltd | Bradford | 2021 |
| Citrine Clinic Limited | Ilford | 2025 |
| Citrine Luna Ltd | Clacton On Sea | 2017 |
| Citrine Spa Basingstoke Limited | Enfield | 2022 |
| Citroen Car Club Limited | Chichester | 2002 |
| Citrus F.S. Limited | Solihull | 2006 |
| Citrus Foundation Limited | London | 2026 |
| Citrus Hair & Beauty Limited | Derby | 2008 |
| Citrus Management Limited | London | 2026 |
| Citrus Relocation Services Limited | Northampton | 2006 |
| Citrus Rooms Beauty (ST Ives) Limited | St. Neots | 2016 |
| Citrus Training Limited | Irthlingborough | 2004 |
| Cittaslow UK CIC | Mold | 2009 |
| City & Central Barber Shops Ltd | Ilford | 2016 |
| City & Country Shutters Limited | Chigwell | 2018 |
| City & Urban Leasing Limited | Wanstead | 2017 |
| City & Westend Environmental Ltd | London | 2007 |
| City Address Limited | Eastbourne | 2021 |
| City Advisory Group Ltd | London | 2024 |
| City Aesthetics Limited | East Boldon | 2019 |
| City Agency Ltd | Liverpool | 2022 |
| City and Guilds Enterprises Ltd. | London | 2004 |
| City and Westminster Limited | Borehamwood | 1982 |
| City Bandit Limited | Leicester | 2022 |
| City Barber (UK) Limited | | 2007 |