The move by Britain's fourth largest bank is expected to create 1500 jobs, and is aimed at increasing market share.
The new branches will be opened over the next five years, with around 12 expected in 2006.
HBOS currently has around 1000 Halifax branches and 300 Bank of Scotland branches nationwide, giving it around ten per cent of high street bank and building society presence.
The company has also reported an increase in 2005 pre-tax profits of 17 per cent year-on-year, of Â£4.8 billion.
"The economic background to trading in the UK remains encouraging," HBOS UK chief executive James Crosby commented on the figures.
However, the markets have not responded well to HBOS' results.
Early trading on Wednesday saw HBOS shares fall by 4.9 per cent, after broker Dresdner Kleinwort Wasserstein cut its recommendation on the stock from "add" to "hold".