Shaw Gibbs, the ECI Partners-backed top 35 accountancy, tax and business advisory group, has acquired Calculo Tax Audit Limited (“Calculo”), a chartered accountancy practice with offices in High Wycombe and Bicester and approximately 1,300 clients. Calculo’s client base is a mix of audit and accounts and tax based work as well as specialism in service charge accounting.
With a total team of 27 led by Jonathan Walton and Rebecca Craker, Calculo provides audit and assurance, accounts, tax, payroll, outsourced accounting and business advisory services.
The acquisition supports Shaw Gibbs’ strategy of combining strong local client relationships and high-quality personal service with the broader capabilities, technical expertise and resources of a growing national group. It strengthens the Group’s presence across Oxfordshire and Buckinghamshire alongside its Oxford base.
Calculo was established in 2024 following a demerger from a previous firm, although the business was formed from two long-established offices with an existing client base and an experienced management team.
The High Wycombe and Bicester offices complement Shaw Gibbs’ existing Oxford presence, strengthening the Group’s ability to support businesses and individuals across the Thames Valley.
The firm will trade as Calculo Tax Audit, part of the Shaw Gibbs Group, with its existing team and client relationships remaining central to the business.
Clients will continue to receive the personal service and local knowledge they value, while gaining access to the wider capabilities of Shaw Gibbs, including specialist tax, corporate finance, business advisory and audit expertise. Calculo’s people gain a wider professional network, enhanced learning and development opportunities and the support of a larger multidisciplinary group.
Peter O’Connell, CEO of Shaw Gibbs, said:
“Calculo is a high-quality practice with strong local relationships, an experienced team and an approach to client service that aligns closely with our own.
“Its presence in High Wycombe and Bicester is a natural fit with our Oxford base and strengthens our presence across the Thames Valley. I’m delighted to welcome Jonathan, Rebecca and the whole Calculo team to Shaw Gibbs.”
Jonathan Walton, Director of Calculo, said:
“Finding the right home for Calculo has been extremely important to us. Shaw Gibbs shares our commitment to personal service and trusted client relationships, while giving us access to much broader expertise and resources.
“It means we can retain what makes Calculo special while creating new opportunities for our clients and our people.”
Jonathan Walton, Director of Calculo, said:
“Finding the right home for Calculo has been extremely important to us. Shaw Gibbs shares our commitment to personal service and trusted client relationships, while giving us access to much broader expertise and resources.
“It means we can retain what makes Calculo special while creating new opportunities for our clients and our people.”
Rebecca Craker, Director of Calculo, said:
“Our clients value accessible, proactive advice from people who understand their businesses, and preserving that approach was very important to us.
“Joining Shaw Gibbs allows us to continue providing that personal service while giving our clients access to a much wider range of specialist expertise and creating exciting opportunities for our team.”
Backed by ECI Partners, Shaw Gibbs supports more than 25,000 clients across the UK and Ireland, combining strong local relationships with specialist technical expertise across audit, accounting, tax and advisory services. The acquisition marks another step in the Group’s expansion across the UK and Ireland.
For further information, please contact:
Shaw Gibbs:
Fran Kidd
fran.kidd@shawgibbs.com
+44 (0) 1865 292297
About Shaw Gibbs
Shaw Gibbs is a top 35 accountancy practice who provide expert solutions for private individuals, entrepreneurial businesses, public sector/non-profit organisations, and international groups. Investing in teams of high-quality specialists, they work with the best-in-breed technology to create value for clients which exceeds expectation.
About Calculo
Calculo Tax Audit Limited (“Calculo”) is a chartered accountancy and professional services practice with offices in High Wycombe and Bicester, providing accounting, tax and advisory services to businesses and individuals.
The firm provides services spanning audit and assurance, accounts, taxation, payroll, outsourced accounting and business advisory. It supports approximately 1,300 clients through a team of [28] people, led by Jonathan Walton and Rebecca Craker.
Following its acquisition by Shaw Gibbs, the firm will trade as Calculo Tax Audit, part of the Shaw Gibbs Group.