"Our intent is to position the Halifax for future growth, in line with our mission to be the biggest and best personal finance business in the UK," chief executive Mike Blackburn said.
He added: "This means providing our growing operations with additional, highly skilled staff, at the same time as creating a more efficient and effective central support function for the group as a whole."
Halifax, which last year merged with Leeds building society, intends to lose a total of 1,200 jobs, but simultaneously create 1,000 posts in its general insurance and direct telephone banking business.
Halifax employs a total of 27,000 people, including 3,500 at the Halifax head office and 1,500 in Leeds. The majority of the job cuts announced yesterday will be in Halifax.
Working practices and administrative processes within both offices have been reviewed "to support and sustain future expansion", a spokesman said. Staff associations were kept informed of the review and staff were told of the changes today.
The Independent Union of Halifax Staff and the Leeds Staff Association, which jointly represent 85 per cent of staff, said they had secured important agreements with the society.
Ged Nichols, IUHS general secretary, said: "The unions fully comprehend the commercial needs of the Halifax but we have continually asserted that individuals must not be flattened by the march of progress.
"We have, therefore, taken every step possible to protect our members' future."
Clive Webster, LSA general secretary, said his union had worked with the IUHS since the merger announcement in November 1994 to ensure members' interests were protected.
"We have secured key agreements that there will be no compulsory redundancies, on pay and benefits protection and on retraining and redeployments opportunities," he said.