The move will see the firm relocate from its current Baker Street offices to the new headquarters in autumn 2027, providing space for 5,000 staff.

BDO, which has been headquartered in the West End for over a century and at 55 Baker Street since 2007, has taken 220,000 sq ft for its 5,000 London-based employees, representing more than half of its UK footprint.

BDO will be the first major office occupier to take space in the redeveloped former Debenhams building, which is owned and being developed by Ramsbury in partnership with development advisors, Capital Real Estate Partners. The move will make BDO’s letting the largest in the West End this year to date.

In total, the building will provide almost 280,000 sq ft of new workspace, with over 13,000 sq ft of landscaped terracing and views across the capital. It is less than a minute’s walk from Bond Street underground station.

A further 58,000 sq ft of prime office space remains available on the top three floors of the building, benefiting from 9,000 sq ft of private terraces. The building is due to be completed in late 2025.

The M Building has been intelligently designed to improve the wellbeing of its occupants, including dual entrances, an abundance of natural light, expansive terracing and on-site amenities, including changing rooms, showers and bike storage. It is targeting BREEAM Outstanding, Nabers 5*, and an EPC A rating.

Paul Eagland, BDO’s managing partner, said: ‘It’s exciting to have secured such a great building, which helps us meet many of our commitments: to our people, to our clients, the West End of London, and to our planet.

‘Working together is what powers our business, and we remain committed to offering flexible, modern spaces where we can learn together, share ideas and collectively deliver work to our clients.

‘We have a strong attachment to the West End and our new UK headquarters will provide a modern, flexible working space in the beating heart of the regenerated Oxford Street area.

‘It marks the start of a new chapter in BDO’s history and gives us a new home from which to grow our UK business in a responsible and sustainable way.’

Ramsbury directors Lars Drangel and Ola Nilsson, added: ‘It is very exciting to be able to welcome BDO to The M Building and we are looking forward to building a long-term relationship with the team there as we work together to develop a new headquarters they can be justifiably very proud of and that helps them achieve their own ambitions as a business.’

According to CBRE, there is currently 9.1m sq ft of UK office development under construction which could complete this year, 60% of which is in central London.

However, despite the high construction levels, 40% of the UK under construction pipeline to 2028 is already pre-let or under offer, demonstrating the high demand that exists from occupiers for the highest quality stock.

BDO’s investment in London forms a key part of its national property portfolio across 17 UK locations, which are home to its 8,000-strong workforce.

In the last two years, BDO has moved into new premises in Glasgow, Nottingham and Ipswich, and has invested in major refits in Edinburgh, Bristol, and Southampton. It is shortly moving in Guildford and, next month, will move into its new Manchester office, Eden, the most sustainable office building in Manchester.

CBRE and Capital Real Estate Partners advised on the transaction.