| 12 Coral Street Limited | Households | 2016 |
| 12-13 Baxtergate (Whitby) Limited | Real estate | 2023 |
| 14549158 Limited | Information & communication | 2022 |
| 15298075 Ltd | Information & communication | 2023 |
| 27/29 Milton Street Management Company Limited | Households | 2017 |
| 2B HR Limited | Professional & scientific | 2003 |
| 3 Albion Terrace Management Company Limited | Professional & scientific | 2010 |
| 360 Safety Services Ltd | Professional & scientific | 2022 |
| 41 Milton Street Management Company Limited | Real estate | 2011 |
| 43 Ruby Street Saltburn Management Company Limited | Households | 2019 |
| 44 Garnet Street (Freehold) Company Ltd | Households | 2017 |
| 5 Star Civils Ltd | Construction | 2025 |
| 540 Studios Limited | Information & communication | 2019 |
| 68 Ruby Street (Saltburn) Limited | Real estate | 2008 |
| A & J Stubbs Limited | Construction | 2003 |
| A J Premier Trading Ltd | Wholesale & retail | 2026 |
| A R Jackson Ltd | Administrative & support | 2018 |
| A R Retail Ltd | Financial services | 2011 |
| A&C Commercial Ltd | Real estate | 2024 |
| AAA Property & Lettings Ltd | Real estate | 2024 |
| Aahi Homes Limited | Real estate | 2025 |
| AAR Design Services Ltd | Professional & scientific | 2014 |
| Abbey Micropubs Ltd | Hospitality | 2021 |
| Abcarbon Limited | Professional & scientific | 2025 |
| Abel Property Services Limited | Real estate | 2021 |
| AC Engineering Solutions (North East) Ltd | Professional & scientific | 2022 |
| Acclaim Systems Ltd | Information & communication | 2001 |
| Accurate Windows & Doors Ltd | Wholesale & retail | 2018 |
| Across- the- Board Games CIC | Manufacturing | 2021 |
| ACT 74 Ltd | Professional & scientific | 2025 |
| AD Design and Development Ltd | Construction | 2024 |
| Adam Evans Interiors Ltd | Construction | 2020 |
| ADG Teesside Limited | Construction | 2018 |
| Adore Review Everything Ltd | Professional & scientific | 2025 |
| AFE (Solutions) Ltd. | Education | 2006 |
| Airhost for YOU Ltd | Real estate | 2015 |
| ALC Accountancy Services Ltd | Professional & scientific | 2022 |
| Alexandra Investment Company Limited | Other services | 1979 |
| ALG Couriers Ltd | Transport & logistics | 2025 |
| ALG Engineering Services Ltd | Mining & quarrying | 2021 |
| ALL Kinds of Minds Ltd | Education | 2025 |
| Alpha Health & Safety Training Solutions Ltd | Education | 2024 |
| Altair Digital Ltd | Other services | 2024 |
| Always.Services Ltd | Manufacturing | 2021 |
| AMC Home & Craft Ltd | Wholesale & retail | 2020 |
| Ancell Equity Holdings Ltd | Financial services | 2025 |
| Andercote Limited | Hospitality | 2006 |
| Andrew Dunn RE Ltd | Professional & scientific | 2018 |
| Andrew Spenceley Consultancy Limited | Professional & scientific | 2023 |
| Anglo Castles Ltd | Real estate | 2022 |
| AP Model Engineering Limited | Professional & scientific | 2017 |
| Apartments Middlesbrough LLP | | 2014 |
| Apex GAS Plumbing and Heating Services Ltd | Construction | 2017 |
| Apex Rope Access Solutions Ltd | Construction | 2026 |
| Arch & Abbey Ltd | Hospitality | 2018 |
| Archie and BEA Ltd | Wholesale & retail | 2022 |
| Archstone Ventures Ltd | Real estate | 2024 |
| Archway Leisure Limited | Arts & recreation | 2020 |
| Archway Sport and Leisure Limited | Arts & recreation | 2025 |
| Arthuraccess Ltd | Administrative & support | 2016 |
| Ascent Heating and Plumbing Ltd | Construction | 2023 |
| ASH Management and Properties Limited | Real estate | 2012 |
| ASM Wellbeing Limited | Other services | 2026 |
| Aspire - Education and Consultancy Ltd | Education | 2026 |
| AT Engineering Services Ltd | Manufacturing | 2012 |
| Atlas Development Group Ltd | Real estate | 2022 |
| Avocado Printed Gifts Ltd | Wholesale & retail | 2023 |
| AWB Performance Ltd | Manufacturing | 2021 |
| B W Access Ltd | Other services | 2017 |
| Bailey Close Automotive Ltd | Wholesale & retail | 2025 |
| Balmoral Terrace (Saltburn by the Sea) Management Company Limited | Real estate | 2012 |
| Banh Clothing Limited | Wholesale & retail | 2023 |
| BAR45 Ltd | Hospitality | 2023 |
| Barber by the Sea Ltd | Other services | 2023 |
| Barker Bros. Limited | Agriculture & fishing | 2008 |
| Barmet Holdings Limited | Real estate | 2017 |
| Barwick Property Development Ltd | Real estate | 2020 |
| Barwick Property Maintenance Ltd | Construction | 2021 |
| Base Camp Industries Limited | Education | 2022 |
| BB Clinical Solutions Ltd | Health & social care | 2026 |
| BE at the Game Ltd | Arts & recreation | 2020 |
| Beach Bars Ltd | Hospitality | 2026 |
| Beachview Estates Limited | Households | 2024 |
| Beckstones Limited | Real estate | 2004 |
| Beesley Housing Ltd | Real estate | 2020 |
| Bell Plant & Civils Ltd | Construction | 2024 |
| Bello Bistro Ltd | Hospitality | 2024 |
| Bennison Rigging Ltd | Construction | 2023 |
| Bespoke Joinery Liverton Limited | Manufacturing | 2024 |
| Bestill-For Mind and Body C.I.C. | Other services | 2022 |
| Betty’S Bagels Limited | Hospitality | 2026 |
| Beyond BUN Ltd | Hospitality | 2025 |
| Big Mouth Productions Ltd | Arts & recreation | 2013 |
| BL Manufacture Ltd | Wholesale & retail | 2019 |
| Blackthorn Beauty Ltd | Wholesale & retail | 2025 |
| Blinds 2000 Chris Bulmer Limited | Manufacturing | 2009 |
| Blockreach Ltd | Professional & scientific | 2021 |
| Blue Platypus Digital Ltd | Administrative & support | 2026 |
| Blue Thorn Property Ltd | Real estate | 2023 |
| Booskbeck Green Ltd | Hospitality | 2025 |