Some 565 people could lose their jobs under plans by the Nationwide Building Society to shut branches by 2012.
The move affects branches of the Derbyshire, Dumfermline and Cheshire building societies.
Nationwide, which merged with the Derbyshire, Cheshire and Dunfermline societies in 2008, is also closing its Duffield regional office.
It will also shut its regional office in Macclesfield as well as the Cheshire Estate Agency.
The society said the move was a result of slow trading and the close location of the branches to existing Nationwide branches.
Twelve Derbyshire branches will close in Arnold, Buxton, New Mills, Chapel-en-le-Frith, Chester, Coventry, Grimsby, Hanley, Leicester, Loughborough, Manchester and Sheffield.
The Cheshire branches facing closure are Biddulph, Droyleden, Leyland, Poynton and Romiley.
The job losses will include 240 in Derbyshire, 250 in Cheshire and 75 in Dumferline.
Nationwide's branch in Dunfermline will become a dedicated administration centre with the creation of 150 jobs.
Another 90 jobs will be created in Nationwide's Swindon and Northampton offices.
A Nationwide spokesman said the Derbyshire would focus on savings and investments, with the ability to offer a range of Nationwide products.
He said the Duffield regional office would close to reduce duplication of work carried out at other Nationwide offices.
The firm said it would support employees by helping them find jobs within the society or with other firms.
Matthew Wyles, a director of Nationwide, said: "Since rescuing the Derbyshire Building Society during the global financial crisis of 2008/9 we have remained committed to keeping their presence on the High Street.
"But it has become clear that we need to make a number of changes in order to sustain their future viability."