| 3 Shires Craft Workz Ltd | Coventry | 2022 |
| 3 Sisters Bakery Limited | Birmingham | 2014 |
| 3 Stars Above Limited | London | 2013 |
| 3 Transport Refrigeration Ltd | Warrington | 2019 |
| 3 Trees Makery Limited | Fareham | 2023 |
| 3 Way Engineering (2002) Limited | Kent | 2002 |
| 3 WIS UK Limited | Newcastle Upon Tyne | 2023 |
| 3 Words Brewing Ltd | Worcester | 2020 |
| 3 Zero 2 Race Limited | Nuneaton | 2004 |
| 3'S a Crowd Brewing Ltd | Greater Manchester | 2016 |
| 3-D Print Centre Ltd | Bournemouth | 2021 |
| 3-MAKER Limited | Glasgow | 2023 |
| 3-WAY Displays Limited | Chesham | 2000 |
| 30 Bucks Ltd | Greenock | 2021 |
| 30 CP Ltd | Old Harlow | 2019 |
| 30 Superfoods Ltd | Brighton | 2024 |
| 300 Instruments Limited | Stoke-On-Trent | 2023 |
| 300 SC Precision Engineering Ltd | Biggleswade | 2019 |
| 3001 RBT Ltd | Croydon | 2015 |
| 301 Automation Ltd | Matlock | 2015 |
| 301 Packaging Services Ltd | East Leake | 2024 |
| 303 Bikes Ltd | Southampton | 2024 |
| 303 Ltd | Walton-On-Thames | 2026 |
| 304 Stainless Exhaust Parts Ltd | Worcester | 2011 |
| 30:30 Vision Limited | Teignmouth | 2019 |
| 30IPS Limited | Newport | 1989 |
| 30SIX Ltd | Harrogate | 2017 |
| 30THIRTY Print House Limited | High Wycombe | 2018 |
| 31 Air Ltd | Gatwick | 2023 |
| 31 Local Ltd | London | 2025 |
| 310 Machine Repair Ltd | Leeds | 2013 |
| 310NEX Outdoor Media Limited | Cardiff | 2018 |
| 313 Glass Ltd | Bradford | 2026 |
| 313 National Halal Ltd | Mold | 2019 |
| 314 Engineering Ltd | Fareham | 2024 |
| 316 Ltd | Maldon | 2025 |
| 316 Marine Fabrication Limited | Criccieth | 2023 |
| 316 Metal Solutions Limited | Wimborne | 2021 |
| 316 Process Fabrications Ltd | Peterborough | 2021 |
| 316 Sheet Metal Ltd | Grimsby | 2025 |
| 316 Welding & Fabrication Ltd | Bracknell | 2020 |
| 32 Boroughs Ltd | Northwood | 2019 |
| 323 Supplier Limited | Horley | 2024 |
| 323 Welding Ltd | Glenrothes | 2024 |
| 324 Boutique Limited | Radstock | 2025 |
| 325 Fast Food Ltd | Glasgow | 2019 |
| 32GI Limited | Hornchurch | 2018 |
| 32X Games Ltd | London | 2025 |
| 33 Carat Ltd | Glasgow | 2024 |
| 33 Creative DPW Ltd | Stoke-On-Trent | 2017 |
| 33 FAB Ltd | Corby | 2021 |
| 33 Holding Group Limited | London | 2025 |
| 33 RPM Limited | Luton | 1994 |
| 33 Strong Ltd | London | 2025 |
| 333 Design Ltd | Carmarthen | 2021 |
| 333RR Ltd | Golborne | 2020 |
| 3343 Limited | Birmingham | 2014 |
| 338 Cable Hire Ltd | Watford | 2018 |
| 33COCOA Ltd | Bicester | 2024 |
| 33COE.GLASS Jewellery Ltd | Sunderland | 2024 |
| 33DEGREECONSULTANCY Ltd | Nuneaton | 2024 |
| 34 Design Company Ltd | Burnley | 2018 |
| 34 Hereward Gardens N136EU 6EU Limited | London | 2021 |
| 345 Collective Ltd | Glasgow | 2025 |
| 345 Design Limited | Telford | 2017 |
| 34CASTLE Limited | Beaumaris | 2023 |
| 34RR Studio Ltd | Birmingham | 2023 |
| 35 Brewing Company Ltd | Rugby | 2019 |
| 36.7 Studio Ltd | London | 2024 |
| 360 Auto Global Ltd | Basildon | 2023 |
| 360 Beauty Brand Ltd | Rotherham | 2025 |
| 360 Boat Services Ltd | Largs | 2016 |
| 360 Boomerang Booth Limited | Dewsbury | 2020 |
| 360 Clouds Ltd | London | 2017 |
| 360 Cranes Limited | Buckingham | 2023 |
| 360 Degree Brewing Company Ltd | Northampton | 2003 |
| 360 Fabrications Limited | Pershore | 2016 |
| 360 Finish Ltd | Shoreham-By-Sea | 2021 |
| 360 Graffix Ltd | Bedford | 2021 |
| 360 Interiors Limited | Cleethorpes | 2014 |
| 360 Jewellery Limited | London | 2023 |
| 360 Laser Solutions Ltd | Belfast | 2019 |
| 360 Marine Ltd | Wimborne | 2023 |
| 360 Media Works Ltd | Stockton-On-Tees | 2020 |
| 360 Office (North) Limited | Hull | 2021 |
| 360 Plant Ltd | Knutsford | 2008 |
| 360 Plant Services Limited | Southampton | 2015 |
| 360 Recruitment Limited | Nottingham | 2010 |
| 360 Repair Ltd | London | 2024 |
| 360 Rugz Ltd | Willenhall | 2026 |
| 360 Safety & Engineering Limited | Ayr | 2013 |
| 360 Telemetry Ltd | Bolton | 2008 |
| 360 Vision Technology Limited | Cheshire | 2003 |
| 360 Wellness Hub Ltd | Bournemouth | 2025 |
| 360 Windows Ltd | Redhill | 2022 |
| 360 Workshop Services Limited | Ayr | 2026 |
| 360-CARPENTRY Limited | Ely | 2023 |
| 360ANDVIBES Limited | Birmingham | 2022 |
| 360BUBBLE Ltd | Newport | 2018 |
| 360DENT Ltd | Ilkley | 2019 |