| Armonialuxury Ltd | London | 2025 |
| Armor Safety & Security Ltd | London | 2009 |
| Armoraro Solutions Ltd | London | 2024 |
| Armorduct Systems Limited | Andover | 1998 |
| Armored (UK) Limited | London | 2005 |
| Armorgard Limited | Fareham | 2013 |
| Armorive Limited | Fareham | 2024 |
| Armorpax Ltd | Waterlooville | 2021 |
| Armortag Ltd | Stourbridge | 2023 |
| Armortek Limited | Chandler'S Ford | 2007 |
| Armos Ltd | Birmingham | 2013 |
| Armoto Ltd | Chesterfield | 2015 |
| Armour Class Limited | Glasgow | 2004 |
| Armour Coatings Limited | Thornaby | 2019 |
| Armour DS Ltd | Wallsend | 2017 |
| Armour Electrical Services Ltd | Enfield | 2020 |
| Armour Engineering Ltd | East Bergholt | 2010 |
| Armour Foods Limited | Stockport | 2018 |
| Armour Glass Limited | Keighley | 2009 |
| Armour Home Electronics Limited | Bishop'S Stortford | 1980 |
| Armour Industries Ltd | Liverpool | 2023 |
| Armour Jewellery Limited | Altrincham | 2025 |
| Armour Ltd | Gravesend | 2023 |
| Armour Media Ltd | Crawley | 2019 |
| Armour Motor Products (Bournemouth) Limited | Bournemouth | 1973 |
| Armour Plastics Limited | Sunderland | 1971 |
| Armour Pumps Limited | London | 2026 |
| Armour Systems Limited | Milton Keynes | 2013 |
| Armour Windows Limited | Chipping Sodbury | 1996 |
| Armourcoat Limited | Sevenoaks | 1986 |
| Armourdillo Ltd | Prestatyn | 2018 |
| Armoured Engineering Ltd | Romney Marsh | 2016 |
| Armoured Martial Arts Ltd | Nottingham | 2023 |
| Armoured Surfaces Ltd | London | 2026 |
| Armourfast (London) Limited | Grays | 2014 |
| Armourflex Sports Limited | Rochford | 2013 |
| Armourlight Limited | Bognor Regis | 2015 |
| Armourlite Ltd | Bilston | 2011 |
| Armourpost Limited | Gateshead | 1991 |
| Armoury Sign Company Ltd | Ebbw Vale | 2022 |
| Armoury Square Limited | | 1908 |
| Arms Khinda Limited | Coventry | 2008 |
| Armsconstruction Limited | Worthing | 2025 |
| Armson Engineering Limited | Newcastle Upon Tyne | 2020 |
| Armson-Boult Ltd | Coventry | 2015 |
| Armstorm Ltd | Haslemere | 2003 |
| Armstrong & Holmes Limited | Grantham | 1977 |
| Armstrong Composites Limited | Coventry | 2023 |
| Armstrong Fabrication Limited | Bishop Auckland | 2025 |
| Armstrong Games Ltd | Sandwich | 2023 |
| Armstrong Hydraulic Services (Hull) Limited | Hull | 1985 |
| Armstrong Industries Limited | Coventry | 1996 |
| Armstrong INK Limited | Sudbury | 2016 |
| Armstrong Integrated Limited | Manchester | 2003 |
| Armstrong Integrated Systems Limited | Manchester | 2004 |
| Armstrong Joinery (West Auckland) Limited | West Auckland | 2023 |
| Armstrong Joinery Products Limited | Thornhill | 2002 |
| Armstrong Jordan Limited | Bishops Stortford | 2005 |
| Armstrong Lyon Hydraulics Limited | Park North | 1972 |
| Armstrong Manufacturing Ltd | Exhall | 2022 |
| Armstrong Meats Limited | | 2004 |
| Armstrong Mechanical Services Ltd. | Edinburgh | 2010 |
| Armstrong Medical Ltd | Coleraine | 1991 |
| Armstrong Motorcycles Limited | Liverpool | 2009 |
| Armstrong Music Ltd | Ashford | 2022 |
| Armstrong Oiler Company Limited | Leeds | 1903 |
| Armstrong Optical Limited | Kings Park Road Northampton | 1997 |
| Armstrong Painting Services Ltd | South Shields | 2014 |
| Armstrong Prefab Services Ltd | London | 2026 |
| Armstrong Printing (Alloa) Limited | Stirling | 2012 |
| Armstrong Products Limited | Huddersfield | 2009 |
| Armstrong Pumps Limited | Manchester | 1977 |
| Armstrong Quattropillar Ltd | Ballymena | 2022 |
| Armstrong Refrigeration Services Limited | Woodhall Spa | 2009 |
| Armstrong Roofing Components Limited | Glasgow | 1990 |
| Armstrong Siddeley Limited | Otley | 2020 |
| Armstrong Vinton Furniture Limited | London | 2012 |
| Armstrong Watches Ltd | Wigan | 2026 |
| Armstrong Welding & Fabrication Ltd | Glasgow | 2011 |
| Armstrongs Bakers Limited | Lancashire | 2008 |
| Armstrongs Blacksmiths & Engineers Ltd | Tamworth | 2022 |
| Armstrotech Ltd | Sheffield | 2021 |
| Armtec Engineering Ltd | North Shields | 2016 |
| Armtech Services Ltd | Alnwick | 2026 |
| Armtrac Holdings Ltd | Burwell | 2025 |
| Armtrac Limited | Burwell | 2000 |
| Armultra Limited | Great Yarmouth | 1985 |
| Armure Armatura Ltd | London | 2024 |
| Armx Technology and Innovation Ltd | Buckhurst Hill | 2024 |
| Army and Navy C.S.L Limited | Leighton Buzzard | 2016 |
| Army and Navy Gunmakers Limited | Leighton Buzzard | 2016 |
| Armybits Limited | Woking | 2020 |
| ARN CNC Ltd | Frome | 2020 |
| ARN Impex Ltd | Bradford | 2020 |
| ARN Technologies Ltd | London | 2026 |
| Arna Purna Trekking Ltd | Chelmsford | 2020 |
| Arnai UK Ltd | Leeds | 2023 |
| Arnamsco Ltd | Birmingham | 2024 |
| Arnaouti Pitta Bread Bakery Limited | London | 1978 |
| Arnarya Ltd | Barnsley | 2025 |