Potter Baker has two offices in Launceston and Tavistock, which brings Baldwins’ total to 56, with the Cornish firm’s 15 staff joining the 1500 across the Baldwins group.
The acquisition, announced on Wednesday, will see revenue grow to £90m.
Baldwins has been buying up firms all across the UK after joining Cogital Group in November last year.
The group, chaired by former Deloitte chief executive John Connelly, was launched as a merger between Baldwins, Blick Rothenberg and Nordic firm Visma at the end of last year.
This is the group’s first acquisition in Cornwall and the latest in its West Country expansion, following on from the acquisition on Devon-based firm Davidsons in May – Matthew Gard, managing director of Davidsons, will lead the region.
Baldwins made its biggest acquisition yet in October when it acquired Scottish accountancy firm Campbell Dallas, alongside another Scottish firm Springfords.
It then acquired Cheltenham firm David Mayers Barnett on 31 October.
Some of the other acquisitions this year include Finnieston Berry Partnership Limited in Birmingham, Minshalls Chartered Accountants in Nottinghamshire, S V Bye in North Yorkshire, Newcastle-based CTC Chartered Accountants, Burton Sweet in Gloucester, KTS Owns Thomas in Wales, Rice and Co in Cannock.